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SOCCER ARTICALS Football training: the demands of the game and the attributes required for specific football positions Football players need specific physical and skill based attributes for each position By: Simon Thadani Football conditioning has become much more specific and scientific. Professional players are now subject to a rigorous fitness regime to get them – and crucially maintain them – as match ready as possible, but this does not mean that all players train exactly the same
Football is changing, whether we like it or not, and over the seven years I have worked with Pro Zone (a match analysis system) it has become very noticeable that Championship and Premiership players seem to be working more intensely, covering more distance on the pitch, year in year out (see the future of conditioning within football). Therefore, training must continue to reflect the ever-changing demands of the game. Football is a skilled team based sport, all about technique, decision making and creative play. It is a continuous, multi-directional, multi-paced, explosive sport but with an aerobic foundation. In terms of the overall playing demands across the year, it is a marathon and not a sprint. A game is played on average every five days for nine months. I have the highest respect for boxers, rugby players and track and field athletes, to such an extent that I spend a lot of time talking to the respective sports’ coaches and participants. I look at their training methods and their physical and mental approach. There is a lot to learn from them. This has made me a better conditioning coach and hopefully in turn improved my players’ condition. But I believe that football is unique, in regard to the short-, mid- and long-term demands of a season. Other sportsmen and sportswomen may say that footballers have an easy life, that they don’t work enough, or are not fit or strong and so on. To these my reply has always been: come and join in for a few weeks or look at the training programme, remembering of course what you have to do with a ball. You need supreme physical condition and playing skill. Over the years, several different athletes from different sports have done this and I would like to think they have changed their opinion in consequence. I’m sure, though, that this change in opinion would be the same if a footballer participated in the training regimes of these other athletes’ sports. Yes, football can learn from other sports, but the game itself, ex-players, coaches, managers, other teams’ methods at home and abroad, can teach football more.
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The demands of the game
The actual demands of a game Let’s now take a look at what players do in an average match, based on playing position. As I pointed out in my other articles there is 10-30% different in the fitness
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SOCCER ARTICALS levels between amateur and professional players. By understanding the demands of the game, specific to position, it will be easier to design position specific drills and training programmes. I use the following acronym to assist with specific player conditioning FITT - this stands for, Frequency, Intensity, Type and Time.
Full backs Total distance covered 11.22km High intensity distance covered 1130m Sprint distance covered 350m Number of high intensity activities 157 Number of sprints 54 Centre backs Total distance covered 10.32km High intensity distance covered 764m Sprint distance covered 211m Number of high intensity activities 112 Number of sprints 33 Wide Total distance covered 11.70km Midfield High intensity distance covered 1390m Sprint distance covered 430m Number of high intensity activities 182 Number of sprints 63 Central Total distance covered 11.73km Midfield High intensity distance covered 1144m Sprint distance covered 302m Number of high intensity activities 169 Number of sprints 49
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The following statistics are provided by ProZone:
Attacker Total distance covered 10.72km High intensity distance covered 106m Sprint distance covered 351m Number of high intensity activities 142 Number of sprints 51 Note: attacker = either the ‘target’ or ‘channel man’ Key to figures Distance covered, from walking to sprinting in 90 minutes High Intensity >5.5 metres per second Sprints > 7.0 metres per second These stats do not show that players will change direction over 1,000 times and turn (over 120 degrees or more) 450 times a match. Also not shown is the time between each high intensity effort ¬– this is on average 60 seconds for centre backs, 32 seconds
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SOCCER ARTICALS for fullbacks, 34 seconds for wide midfielders, 36 seconds for centre midfielders and 39 seconds for centre forwards. Also not shown is the number of tackles and jumps etc made. These are very important factors because turning, twisting, changing directions, jumping and tackling take a lot out of players physically.
Despite some experts’ beliefs that each outfield playing position should have a certain physical standard/profile (body type) so that you get the best out of them playing wise, I disagree. Yes, generally speaking it might be advantageous if an attacker is 6’3’ and well-built, but I believe that if the player has other exceptional attributes, then it doesn’t matter what height or body type they have. Footballing ability will often outweigh physical attributes. Look at the Spanish national team’s victory over Germany in the recent European Championship final, they were much slighter than the more heavily built Germans. Then there are players like Roberto Carlos, Lionel Messi, Michael Owen, Fabio Cannavaro, Aaron Lennon, Shaun Wright Philips and Deco, the list is endless, of these great but not physically big players.
A guide to the physical attributes required for players related to their playing position For me every player needs to be fit, strong, agile and fast. In the perfect team all the players would possess these attributes. However, we don’t live in a perfect world. I have therefore identified the key training requirements of players according to position. Speed, stamina and mental attitude will be the key underpinning elements, for all positions.
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Footballers can come in all shapes and sizes
Centre backs • Powerful, dynamic strength • Physically strong under contact situations • Vertical, single leg jumping power • Balanced – rarely talked about in fitness, but important in this position • Agile – must be able to turn quickly in both directions • Anaerobically very fit position, lots of explosive training required • High endurance capacity not needed – can get away with a relatively low VO2max (VO2max is a measure of the body’s oxygen processing capability) • Ideally have pace – becomes more important if the player is not physically that big • Should enjoy the contact side of the sport • Must be very mentally strong
Full backs
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SOCCER ARTICALS • High aerobic capacity (looking for a VO2max of 63/64ml of oxygen per kg of body weight) • Some top managers expect full backs to be the fittest players in the team • Speed endurance work is very important • The modern game is tending to use taller players in this position although this is not essential • Aerobic recovery interval training (based on heart rate) is important • Players with pace will stand out in this position
• Good aerobic foundation is essential. They are the ‘engine room of the team’ • Physically the team’s ‘all rounder’ does a lot of everything • Holding midfielders, strong, agile and good in the tackle • Advanced midfielders are ‘box to box’, high intensity players, training must reflect this, will need to do, for example, more longer sprint work • Ideally should be two-footed • Are always twisting, turning and changing directions, must therefore have very good local muscular endurance and be very highly fatigue resistant • Pace – this will be very much a bonus
Wide midfielders • Some of the fittest players in the team - VO2max of 63/64 ml/kg/body wt • Good recovery rate is important, therefore short recovery work training is essential • Ideally players will have pace • Can be the physically smaller subject to the team’s format. • Mobile and agile – therefore need to do relevant agility and power work • Two-footed players in this position will be a massive advantage to be able to go inside and outside of defenders, for example
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Central midfielders
Centre forward – target man • Usually big players with a presence • Ideally with good agility and balance under pressure – therefore need relevant agility and power training • Dynamically strong players • Vertical, single leg jumping power • Explosive position, training should reflect that – work on the first step and accleration • Average VO2max, approx 59 ml/kg/body wt • Must enjoy the contact side of the sport • If timings of jumps are a conditioning issue, than this is important and should be specifically worked on
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SOCCER ARTICALS Centre forward – channel man • Fit players, with above average VO2max • Good pace, some of the quickest players in the team • Speed endurance training is essential • Agile, in the respect of turning quickly – this skill should be practised • Balance • Explosive position, therefore training should reflect that, for example for linear and curvilinear acceleration • Strength required, for example to hold off defenders
Football fitness- conditioning techniques to ensure you stay in shape the whole season By: Simon Thadani Football is one of the most unique and demanding sports. At the top level, players are expected to play 50 or more matches in a season that lasts nine months, and the physical toll is increased by all the training between matches, as well as the travelling up and down the country and abroad. Players are mentally and physically fully taxed. Football is rightly described as ‘a marathon, not a sprint’. Once pre-season has been completed and professional teams are into league and cup games, conditioning does not take priority for the regular starting 11 players. Rather, games, football training (ie, with the ball) and recovery/rest days become the priority. Conditioning comes next, but I am always looking to continue a player’s individual personal development – to keep them as match-sharp as possible.
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Football training: how to maintain fitness all year round
Training and playing is conditioning. This means that football training and games maintain aerobic and anaerobic fitness, for example. And if you plan with the football coaches, you can cover other conditioning aspects, such as strength, speed and power, within specific football sessions. It really depends on where you are in the playing cycle, what your conditioning priorities are and how you want to achieve them. The great Muhammad Ali neatly neatly summed up the importance of getting training right when he said: ‘The fight is won and lost far away from witnesses, it’s won behind the lines, in the gym and out there on the roads, long before I dance under those lights.’ So how do you – as a football conditioning coach – ensure that your players are able to perform at maximum in their ‘fight arena’?
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SOCCER ARTICALS Amateur players
Personal Responsibility In Developing Excellence
Guidelines for progressing footballers’ conditioning across the season Early in-season Match analysis systems quite clearly indicate that players continue to improve their match fitness several games into the season. At this time, subject to fixtures, you are looking to overload the players three times a week. Note that this also includes matches and can be done either by football training or specific conditioning. Individual strength programmes are continuing during this period. It is also important to continue to develop speed and power.
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A great deal depends on how high you are up the non-league ladder and why you play football. The higher you are, the more seriously you should take your conditioning. If you train (with the team) twice a week then you should certainly fit in conditioning work within these sessions. However, you should also do more conditioning within your own time. As a conditioning coach, you need to give players guidelines and programmes to follow and do, and trust (but monitor) that they get on with them. Consequently you must encourage players to keep you informed of what they have done so you can start to build up a picture of their condition. Following the PRIDE acronym will help – this is used in professional football, but it is just as important in the amateur game. It stands for:
Examples of drills we might use: 1) High-intensity aerobic/anaerobic without ball This drill will be used if we are playing Saturday-to-Saturday fixtures and football training is not of a high intensity. Mark out a 300m oval track and place cones in a straight line at intervals of 4m, 8m, 12m, 16m and 20m within it (depending on the number of players you are working with, more than one lane can be marked out). a) Players run around the 300m track in 50 seconds – this time is based on professional players. They rest for one minute and go again. Three further runs are completed. b) They then do a simple ‘doggy drill’ (normal running action, there and back, there and back, etc) to the 4m cone and back, then to the 8m cone and back.
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SOCCER ARTICALS This pattern is repeated to the remaining 12m, 16m and 20m cones. The drill is completed at 100% effort. Professional players will complete the course in less than 27 seconds. The players rest for one and a half minutes and then go again. This constitutes one set – each contains two efforts. Aim for two to four sets. This is a very tough session. 2) High-intensity aerobic/anaerobic workout with ball
Around Christmas time In the professional game, Christmas and the New Year is a very hectic period, so the four ‘Rs’ take priority – Rest, Recovery, Rehydration and Refuelling. However, lower down the amateur leagues this time could be ideal to have a mini-break and then do some serious training, such as speed-endurance or strength and power work. Examples of drills we might use: 1) Speed endurance without ball Jog 5 metres and then sprint 30 metres Jog 5 metres and then sprint 35 metres Jog 5 metres and then sprint 40 metres Jog 5 metres and then sprint 45 metres Recovery – walk for 2 minutes between sets
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This drill uses a pitch, approximately 42m by 35m, with two goals and two goalkeepers and two teams of five outfield players. You’ll also need about 20 balls – these are spread out around the outside of the pitch. Players basically play a high intensity fivea-side for four minutes and then take an active rest (this can involve walking and light jogging) of 90 seconds. The emphasis is on continuous play (hence the spare balls). Repeat four to six times.
Do: 4-6 sets 2) Speed endurance with ball Cones- f d b o a c e Players - *1 *2 Use six cones - a b c d e f and o (as shown in diagram). The players start at cone ‘o’. The players are marked as *1 and *2. Distance between each cone is 5 yards.
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SOCCER ARTICALS Each player has a ball and they face in opposite directions. At the command ‘go’, player 1 sprint-dribbles to cone ‘b’ and leaves the ball there. He then turns and sprints to collect his partner’s ball at ‘a’. At the same time, player 2 has sprint-dribbled to ‘a’, left the ball there, turned and sprinted to ‘b’, where he collects the ball left by player 1. On arriving at their respective cones (b and a), the players each collect their partner’s ball (as noted), turn and sprint with the ball to cones ‘d’ and ‘c.’ respectively. They leave the balls at these cones, then turn and sprint to collect their partner’s ball, then turn and sprint-dribble with the ball to cones ‘f’ and ‘e’ respectively, where they leave the balls, turn and sprint to pick up their partner’s ball, and turn and sprint back with the ball to ‘o.’ Professional players take less than 20 seconds to complete this drill.
Maintenance period The maintenance period usually starts around February time. Prozone (this is a very precise method of measuring player movements and intensity on pitch) has clearly shown me that it’s rare that professional players beat their on-field performance bests – for example, for a wide midfield player, 13km (distance covered) 2000 metres (high intensity) and 600metres (sprint work) in a match. They are as fit, strong and quick as you will get them at this time of the season and they will have played some 30-plus games. If you can get them to continually match their personal bests, week in, week out, then you have done well. The next three to four months of the season will be a real challenge – players’ physical condition must be maintained, without dips in performance.
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Do: 10-12 times with 40 seconds’ active recovery.
Examples of drills we might use: Football maintains many of the components of conditioning. But, subject to what the players do in football training, you may need to top up certain aspects, such as speed or endurance. This is the time of year when I like to move outside and continue to develop the strength that has been developed inside in the gym and sports hall, via the use of fresh new drills and workouts. Over-speed drill – slingshot, using bungees, for speed This drill improves stride rate, stride frequency, arm swing acceleration and reflexes. Two players work together, one resisting and holding the bungee tension and the other working. You need one harness and two bungees, which are attached together. Players stand 25m apart. Player 1 wears the harness and player 2 provides the resistance.
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SOCCER ARTICALS On the shout ‘go’, player 2 sprints 5m and stops. At the same time, player 1(sprinting approx 30m) sprints past player 2 and stops slowly. The drill is repeated three or four times, after which the players sprint without resistance.
End-of-season
Examples of training we might use instead of football training: 1. 2. 3. 4. 5.
Simple pool sessions – moderate intensity level Spinning bike sessions – moderate intensity level Volleyball competition – light intensity level Football head tennis competition – light intensity level Cycling around a park or lake – light/moderate level.
Golden tips for conditioning during the season Prioritise conditioning; you can’t do everything you know that players need.
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This is a highly dangerous period, physically and mentally – one when players can and do get injured. Forty-five games might have been played, but those last five or more could be the most important, sorting out relegation or promotion. Attitude, motivation, over-training, under-training and fatigue become big issues; so it is important to keep training fresh to keep the players fresh. I give them variety by introducing cross-training and striving to keep them mentally positive. ‘Short and sharp’ is very much my training mantra at this time. Stretching is also emphasised.
The starting 11 will have a different schedule from the rest of the squad. With the latter you must ensure that their fitness levels are high enough so that, if they are called upon, they can slot into the first team without their fitness being an issue. Amateur players, subject to what level they play at and why they play, should take responsibility for doing extra conditioning work in their own time. If your players are playing two games a week, eg, Saturdays and Tuesdays, then conditioning takes a back seat and the four ‘Rs’ take priority. Do not underestimate the benefit of sleep and of not disturbing the sleep patterns as part of recovery. Nutrition is very important – get specialised help. Food and fluid intake does affect performances. It is interesting to note that younger professional players do not seem to adhere to this, while older players seem to take it on board. Have the latter learned from their mistakes? When working on a weekly cycle (Saturday to Saturday matches) follow the tapering principles, ie, do conditioning drills in the early part of the week and technical, higher-quality work closer to matches. Prioritise the conditioning components to the individual and the team.
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cardiovascular fitness, subject to the time of the season, is to train three times a week, ideally achieving approximately 16 to 20 minutes in the upper training zone (85% to 95% of heart rate maximum). Note: there will always be exceptions to this rule. Try to have a ‘theme’ for every warm-up, which works on a conditioning component as well as warms the player up. Themes could be speed with relay races, or acceleration, or technique work, power with plyometrics or resistance sprint work, such as hill work or mobility with dynamic stretching, or strength work with press ups, core work and lunges, etc. A little and often specific conditioning work is better than none, so plan ahead. Do the simple things well. Keep the sessions simple and specific, especially if time is an issue and overtraining is to be avoided. Mix it up – keep conditioning fresh. There will by necessity be certain conditioning aspects you must continually repeat, but when the opportunity arises, employ variety. Examples include using different coaches to do sessions, sprint relays with a baton or a rugby or a tennis ball, or in different locations, and so on. Do drills accurately and with specificity in mind. For example, in a match, players walk, jog, run and sprint, so your aerobic and anaerobic workouts without a ball should reflect this. As a specific example, sprints in a game last between two and five seconds, therefore drills should reflect this Plan ahead as much as possible. Speak to the football coaches and work with them and find slots where football training intensity is low or moderate and then plan your conditioning. Failing to plan is planning to fail. Educate the players why they are doing specific drills and suchlike. Get them to ‘buy into’ what they are doing by telling them that they will become better players. Heart-rate monitors are a good way to monitor players’ training – although they are not infallible, they will allow a good degree of control. Player mentality is important. Players will always ‘moan’ when they have to do a hard specific conditioning drill – it’s their nature! Their attitude on the day will always have an effect on the drill, so be positive and reinforce that it will make them better players.
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Although every player is genetically different, our basic rule for improving
Simon’s star tip Hard work There is no substitute for hard physical work, at the right time and place. All the sports science, nutritional information and gadgets will never replace the passion, desire and the will to win that hard physical work can give you.
Football training: the importance of testing for players and coaches 10
SOCCER ARTICALS Testing is an objective way of confirming a coach or manager's thoughts By: Simon Thadani
Basically, the extent of testing and monitoring usually reflects the manager’s and coaches’ philosophy on how players should train and play and how their condition should be measured. Conditioning coaches will also try to educate them on the importance of having some measurable standards in place to back up/confirm what the manager and coaches see in training and games. My opinion is simple: testing is important but it should be kept simple and, just as crucially, should be specific to the game. Testing is not only evaluative, but also about educating the players about the importance and the benefits of being tested (i.e. so that they can strive for higher levels of condition). Testing is also an objective way of confirming the manager’s/coaches’ thoughts.
What tests should you do? Several years ago I went to a course run by the Football Association. There were around 20 conditioning coaches on the course, from the Premiership and the Championship. The tutors asked us to compile a list of the tests we do at our clubs both past and present. Most of us were expecting maybe a total of 12 to 15 tests. When the combined list came back, there were 30-plus tests, several of which I and many others had never heard of! The point I am trying to get over is that there are so many different opinions in the game regarding testing.
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I have had the privilege to work with several top managers and coaches. I have also talked to many other conditioning coaches, managers, coaches and visited several other clubs over the years, and many of them have different opinions on testing players. Some were not convinced about the benefits, whereas others would be, and would have a whole battery of tests. And then again, there would be clubs that perhaps used only one or two tests.
Football is a multi-directional and multi-paced explosive game, primarily anaerobic, but with an aerobic foundation. We should therefore test those components, more specifically as aerobic endurance; speed; and speed, agility, power and recovery rate. Testing amateur players When testing amateur teams, ask yourself two very important questions: how much time does the team have to train, and why does the team play? If your team plays Saturday to Saturday (or Sunday to Sunday) and does not train between games, then it will be very difficult to test players, therefore testing might not be feasible. This is because you will not specifically be working on developing improved football condition. If your team plays for the fun of playing and the social side of football, then
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SOCCER ARTICALS I think testing is not relevant, it’s important that players to continue to enjoy and love the game. However, if your players are more serious and regular training does take place, or they are at a higher level, then testing becomes more relevant and appropriate. Difference between professional and amateur players Subject to your standard of play, you are looking at (subject to the tests used) a difference of 10% to 25% between amateurs and professionals. However, you should be less concerned with this variance and more with past testing history. This will give you a better indication of fitness levels and the effects of the playing and conditioning programme.
To assess fitness levels To set programmes and schedules To study the effect of training programmes and matches To turn weakness into strength (team and individual) To motivate players and give them objective feedback To educate players To assess rehabilitation work and post-injury condition To create future standards and a player condition database To monitor over-training To advise the manager of any issues To make players better To give players the confidence to perform well And finally - and often highly underrated – for the mental benefits of telling a player they look and are fit.
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Testing is important for the following reasons:
A very practical look at monitoring and testing, based on my opinion and experience Generally speaking, what follows are examples of what professional clubs (subject to financial status) would monitor in training from Mondays to Fridays. They may use one or more of the following: Heart rate monitors If you are looking to improve a player’s aerobic fitness, research indicates that you need to work players three times a week for 16-20 minutes in the top heart rate zone, ie, 90% to 95% of heart rate max. Heart rate monitors are widely used in the professional game. Resting heart rates and questionnaires
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SOCCER ARTICALS Measuring players’ resting heart rates (RHR*) and using a questionnaire (‘Perceived training loads’), designed to measure the way the player is feeling about their physical condition, can evaluate training status and inform the coach as to whether they need a rest or some lighter work or are OK to carry on at the current intensity. Some clubs use this system, but in my experience it is more widely used abroad. You need to trust your players because they can manipulate the questionnaire answers! * RHR is taken a few moments after waking. A variation from the ‘norm’ can indicate that the players are in an over-trained state. Omega wave system
Player tests Laboratory tests The only two lab tests I would use would be the VO2* and possibly the Wingate test*. I would consider other tests if there were specific individual player issues, for example a need to determine hamstring strength, due to a player’s propensity to sustain strains. The average professional player’s VO2 max is approx 60ml/kg/min (this indicates a high aerobic capacity on a par with a male elite 400m runner, but allows for a significant anaerobic contribution to their ‘energy system power’ - Ed). In terms of anaerobic power and the Wingate test, you are looking at player’s power levels not declining by more than 15-20% between the first and tenth effort.
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Again, only a couple of clubs have this system, due to its cost. It measures the time between heartbeats over several minutes - which in theory, using past history, would give you some feedback on training status.
* The VO2 test measures a player’s maximum aerobic capacity; the Wingate test measures anaerobic power endurance and ‘fade’. Field tests These form the bulk of your tests. Keep them simple and specific. ‘multi-stage bleep’ or ‘Yo Yo’ tests can fall into this category. They are popular all around the world in many different sports. Top international manager Guus Hiddink wants his players to achieve level 14 on the bleep test. The average in the professional game is between 13.8 and 14.2. The 12-minute run is also a test I use – although there are numerous versions (different durations). At Ipswich, players achieve distances of 3.35km/2.06 miles outdoors and 3.41km/2.1 miles on treadmills. Game analysis ProZone or Amisco analysis system (see monitoring section above).
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SOCCER ARTICALS Recovery test There are numerous examples in use that have been designed on an individual basis by different clubs. Ours is simple and easy to do.
Power - vertical jump test Players’ leg power can be measured using a force plate or the much more low-tech sergeant jump. Players use a countermovement jump – they bend and then extend their legs to jump. This utilises the stretch/reflex capacity of muscles. Max jump height is recorded in cm. Professional players average approx 57cm. Speed - linear There are many ways to test for speed. To be 100% accurate, speed gates with infrared beams that time the start and finish and any intermediate points should be used. Players perform a flat-out sprint over 20m, with splits at 5m and 10m to assess acceleration. Static and rolling starts are used. Speed - multi-directional For example, the ‘T agility sprint test’ – where the player has to move forward, laterally and turn. Speed - endurance There are numerous variations to this test. We might do 8 to 10 sprints over 30m or 40m, with a short recovery of 20/30 seconds. We are looking for professional players to not fatigue more than 15% to 20% from effort 1 to effort 10.
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8 x 45 second multi-paced efforts on a pre-set circuit. The players’ heart rates are monitored. The (active) recovery between the circuits is used to monitor their training status. Thus, if a player’s heart rate is dropping and stabilising more quickly than it did during previous tests during the active recovery, then their fitness has improved (active recovery involves gentle CV exercise, eg walking/slow jogging). We look for players to not fatigue by more than 8% in terms of heart rate recovery values, across the circuit.
Strength/local muscular endurance tests Again there are many possibilities. These include using machines (isokinetic – that measure a muscle’s constant force expression over a designated path) or everyday free weights or body weight exercises. Selected scores from professionals: Number of press-ups - 65 Number of clap (plyo) press-ups - 19 Squat – 1.5 times body weight.
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SOCCER ARTICALS A word of caution: any testing is only accurate if the players’ attitude and effort toward them are 100%.
The final whistle on testing Choose the right time to test. Avoid testing players when they are tired, or during a hectic schedule of games. Try to produce the same environment for each test as previously done, eg, after a couple of days off, or always outside on a dry day (professional players are usually tested two to four times a year).
Over the years I would say that the manager and coaches’ observations with reference to conditioning issues in games and training are right 75% of the time. The surprise and food for thought comes with the other 25% of the time! This is when test results could just make the manager and coaches think a bit! And, perhaps, rest or change playing and conditioning in regard to a specific player/players. Having the fittest team in the league will not win you the league. As an exinternational and world cup player once told me (as have many other top coaches), conditioning is a very important aspect of today’s game BUT more importantly, it’s the players’ ATTITUDE, DESIRE. SKILL and ABILITY that matters first and then, and only then, the coaching and conditioning they receive.
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I believe that any test with a ball is testing skill. This makes it very much a coaching issue – therefore, in my opinion, you should avoid testing with a ball.
About Simon Thadani After serving in HM Armed Forces, Simon became a professional football conditioning coach some 20 years ago, with the last 9 years spent at Ipswich Town Football club. Simon has overseen the conditioning of the squad during Ipswich’s promotion and successful Premiership and European campaigns and thereafter the tough and demanding Championship campaigns.
Football matches: half time psychology Effective communication between the coach and players is essential at half time The half-time period in a match is the only direct opportunity the coach has to speak to all the players once the match has started, and to influence the second half performance and result. Effective communication between the coach and players is therefore essential, as Jim Petruzzi explains…
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Maximising second half performance is the goal of any coach and this will entail discussions about tactics, state of the pitch, player formations etc. However, just as important as what is said is how effectively it is communicated. Communication is a 2way process and while most coaches are good at talking to players and giving out instructions, some are less accomplished at listening! This is unfortunate as coaches can often get a good feel for what’s going on by asking players questions and instigating a 2-way discussion. How a coach communicates with the players is partly reflected in his or her leadership style; ideally this style should be adapted to the circumstances of the dressing room. For example, a hostile attitude among the players may require a more autocratic style, whereas a friendly and co-operative attitude may favour a more democratic style. The characteristics of these two styles are summarised below:
Autocratic Style (eg ex-Portugal & Chelsea manager Phil Scolari)
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What a coach says to the players during half-time will depend on both the score, and the perspective of the match. If a team is winning 2-0 at half-time, it will almost certainly go into the changing rooms with a more positive attitude than the opposition. However, suppose the opposition score just before the break; although still losing at half-time, they may well feel very positive, believing that they now have the momentum. The type of game also affects psychological perspectives; knockout games are different to league games and top of the league teams tend to have different expectations to those at the bottom! Whatever the perspective however, the half-time period is crucial because players will have their first opportunity to reflect consciously on the game for an extended period, and the role of the coach is critical.
• The coach decides what needs to be done; • The players do not participate in the decision-making process; • The coach clearly defines how what needs to be done should be done.
Democratic Style – (eg ex-England manager Sven Goran Errikson) • The coach sets out what the players need to achieve; • He then invites the players to out forward ideas or make suggestions on how to go about it; • The coach decides the best course of action based on the suggestions the players have made.
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Using NLP at half-time NLP is about a series of psychological techniques, which can help us gain control over parts of the brain that we normally think of as ‘automatically’ regulating the way we think, behave and perform. And when applied to sport, NLP can help athletes to maximise performance. One of these techniques is positive instruction; instead of a coach telling a player not to miss the target when shooting and create negative thoughts in his or her mind, it’s far more positive to tell the player to hit the target. In relation to half-time, there are 3 very useful techniques that can favourably affect the state of mind of players and coach and maximise second half performance: • Dissociation – this technique recreates a past experience but from the perspective of somebody who was not emotionally involved (eg an onlooker). For example, if the team has conceded a scrappy goal, the coach would try and recreate that experience in the mind, but imagine that he or she is a passive onlooker watching the event. This enables a coach to analyse the situation coolly and logically without emotion, and thus come up with a solution that can be discussed calmly and rationally at half-time; • Reframing – this is about changing the frame of reference in order to interpret a situation in a more positive light. A good example of this was in football’s 2005 European Champions League final. Liverpool were 3-0 down to AC Milan at half-time; during the team-talk, Rafa Benitiz, the Liverpool manager suggested that his players ‘go out and score the first goal and see what happens from there’. This was a far more positive frame of reference than asking them to go out and score 3 goals in order to draw level; • Anchoring – is a useful practical technique to help create a desired state of mind by applying a simple physical stimulus. This involves recalling a powerful memory where you experienced the desired state of mind and then simultaneously creating an ‘anchoring stimulus’ – eg pressing together your thumb and index finger. With enough repetition and practice, merely pressing together your thumb and index finger can be sufficient to reproduce the desired state of mind, whether it be confidence, relaxation
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Whether and who the manager decides to substitute at half-time can make an enormous impact on the second half psychology. If a team is ahead at half-time, substituting an attacking player for a defender may suggest that the manager lacks confidence in holding the lead and has decided to ‘batten down the hatches’! Substituting the team captain can have a devastating impact on a team, suggesting perhaps that the manager in panicking. Putting on a player who’s performed particularly well against the opposition in previous encounters may on the other hand unsettle the opponents! Deciding the best course of action is often a balancing act; if a team is playing well but losing at half-time, should the manager keep the faith and trust that things will come good, or should he or she make a bold attacking substitution, but risk disrupting the flow and cohesion of the first half? In order to make these kind of decisions, it’s important that the manager and players are in the right frame of mind and this is where psychological techniques borrowed from neurolinguistic programming (NLP) can come in handy.
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SOCCER ARTICALS etc. Applying a combination of these techniques at half-time can significantly enhance the performance of both players and coaches, and increase the second half performance of the team. Original article by Jim Petruzzi Summary by Andrew Hamilton BSc Hons MRSC ACSM
Plyometric training: can it improve football performance?
Plyometric type training exercises for power and speed are used with great effect in a number of sports. But how useful are they for footballers? John Shepherd looks at the latest research and comes up with some surprising conclusions‌
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Plyometric type exercises for power and speed are used with great effect but how useful are they for footballers?
Football is a high-intensity intermittent sport. Although players can cover up to 11km in a game, most of this is done in short, sharp bursts lasting seconds, and this performance therefore relies on anaerobic energy, speed and power. Plyometric (jumping) exercises to develop power are used by sportsmen and sportswomen from myriad sports with success. But can they be applied to football and combined with traditional approaches? A plyometric exercise involves the combination of two muscle contractions coming together to enhance muscular power outputs and therefore speed and power (see box 1). Footballers need to posses agility, speed and strength (see box 2) and plyometrics are a great way to condition these outcomes. Firstly, let’s take a look at some research that has examined the inclusion of these types of exercises into football training.
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Swiss researchers examined the effect of surface type (grass or sand) on residual muscle soreness, vertical jump and sprint performance in 37 footballers (2). Why residual muscle soreness? Well, if a player suffers from soreness or gets injured and has to be rehabbed back to full fitness, the knowledge of the best surfaces on which to train will be of great benefit to football conditioners, physiotherapists and managers.
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In the world of sports conditioning, specificity is seen as key in terms of conditioning drills and practice, and maybe, therefore, jumping from sand could be seen as less relevant than jumping from grass. However, it’s not always that simple. To perform a squat jump requires the generation of force from a stationary position, primarily using a concentric muscle contraction in the ankles, thighs and hip muscles. But the counter movement jump utilises the eccentric/concentric stretch shortening cycle interaction and jumping from the softer surface will slow this down. Basically the sand will ‘damp’ the explosive capability of the muscles, which explains the reduced adaptation to this training method of the players in that group. However jumping from sand requires greater strength and this probably explains why the players who performed their plyometrics from this surface improved this jump more significantly. It was as if they were performing their jumps with added resistance, which overloaded their muscles to a greater extent than the grass, producing a resultant increase in strength. What are the lessons here for football conditioners? Varying the surface from which players perform their plyometrics training could yield physiological and performance benefits, and reduce residual muscular soreness, allowing a player to complete more high-intensity training. However, everything else being equal, it’s probably still better that players train on hard dry grass, running tracks or sprung sports hall floors when performing plyometrics. This is because the harder surfaces will help develop a ‘quick fire stretch shortening cycle’, which will translate into improved on-pitch performance.
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Eighteen players followed a four-week plyometric training programme on grass, while 19 followed the same programme on sand. Pre and post-intervention programme, the players were tested on 10m and 20m sprint performance, squat jump and counter movement jump ability. Muscle soreness was tested using a questionnaire. The results showed that both interventions improved sprint speed and squat jump performance similarly. However, it was discovered that the footballers performing plyometrics on sand improved their counter movement jump more than those who jumped from the grass. It was additionally discovered that the players who performed their jumps from sand reported less muscle soreness.
Weight training For comprehensive football conditioning, weight training and plyometrics can be combined. But what kind of weight training protocol works best for footballers? Researchers from Norway examined weight training protocols used by professional football teams (3). Specifically they wanted to find out whether there was a strong relationship between maximal strength, sprint and vertical jump performance among elite players. Seventeen international players, with an average age of 25, participated in the survey. They were tested for maximum half-squat, vertical jump and sprint performance over
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30m and using a 10m-shuttle run. It was discovered that half squat performance was a key determinant of all test performances and it was also noted that this did not compromise anaerobic endurance as measured by the shuttle run. The researchers concluded that ‘elite soccer players should focus on maximal strength training, with emphasis on maximal mobilisation of concentric movements’ (see box 3).
Power combination training Power combination training combines plyometric and weight training exercises into the same workout. The exercises are usually paired and must work the same muscle groups. Typical examples include the squat jump and half squat, and the split jump and the single leg press. Loadings on the weights exercises must be in excess of 70% of one repetition maximum (1RM). This is to ensure that the exercise targets large numbers of fast twitch fibres (a lighter weight would tend to emphasise slow twitch fibres – which have an endurance role and are consequentially much less likely to contribute to power, speed and strength development). Power combination workouts have been shown to enhance the power outputs of fast twitch muscle fibres within the workout and over a training period. This is believed to occur as a result of ‘potentiation’, which is essentially heightened neuromuscular activity in the relevant muscles. The net effect is that an athlete is able to recruit larger numbers of fast twitch muscle fibres without conscious effort, thus boosting their power output.
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SOCCER ARTICALS However, there is some research which argues that this method of training may be less beneficial for football players. Norwegian researchers looked at power combination training methods and their effects on professional players (5). Six players were assigned to a heavy weight training group, who also completed 6-8 specific football sessions a week, whilst 8 players performed plyometrics as well as the heavy strength work and the football sessions. A control group just performed the 6-8 weekly soccer sessions.
The result showed that there were no significant differences between the footballers who had performed the power combination training or the heavy squats only. As a result of these findings, the researchers decided to create just one intervention group with players performing heavy weights and plyometrics. Again, a control group just performed a comparable number of weekly football sessions. The power combination training footballers showed improvements across all tests, except the counter movement jump. These improvements were deemed to be significant for the half squat 1RM and sergeant jump for example. However, non-significant differences were seen on the half squat power tests with 20kg and 35kg loads and all of the sprint tests. This led the researchers to conclude that, ‘there are no significant performanceenhancing effects of combining strength and plyometric training in professional soccer players concurrently performing 6-8 soccer sessions a week compared to strength training alone. However, heavy strength training leads to significant gains in strength and power-related measurements in professional soccer players’.
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The pre- and post-intervention tests used by the researchers included maximum half squat, counter-movement jumps and peak power in half squat with 20kg, 35kg, and 50kg loads (basically the players’ speeds of movement were measured during the half squat with these weights and their power outputs measured). In terms of sprint speed, acceleration, flat out speed and 40m times were tested.
How can these findings be reconciled with the fact that much other research indicates that power combination training works? Simon Thadani is the conditioning coach at Ipswich Town FC, and believes that football conditioners must be conscious of the training that players are doing with the football coaches and that this must all be assessed and added to the overall training load on the players. He provides the following real life scenario: ‘One of the football coaches took away several of the defenders for half an hour to concentrate on heading. I watched the session and observed that each player ended up doing 150 plus headers. I therefore decided that the players had done enough and did not need to do the afternoon session, nor plyometrics the next day.’ Basically, what Simon is noting is that the football sessions were conditioning the jump performance of the players without them having to do a specific jumping workout. This might explain the findings of the Norwegian researchers above; a crucial
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SOCCER ARTICALS consideration for football conditioners (indeed conditioners of all high intensity intermittent sports) is that the physiological demands of the sport itself (both through training and competition) cannot be overlooked as a contributor to the overall training and conditioning load.
Developing the maximum power capabilities of footballers is crucial for maximum playing performance. Although plyometric exercises tick all the right boxes in this respect, it would appear that heavy weight exercises, notably the half squat, are perhaps even more effective as part of a properly constructed training programme. Plyometric exercises, as specific training units, may be more beneficial in pre-season and from an injury prevention perspective (in terms of mastering improved technique and strengthening relevant muscles) in a controlled environment. And, finally, when plyometrics are used, conditioning coaches should also be mindful of the surface on which they are performed, in terms of training response and potential muscle soreness. John Shepherd MA is a specialist health, sport and fitness writer and a former international long jumper References 1) 2) 3) 4) 5)
Journal of Sports Science and Medicine (2007) 6, 63-70 Br J Sports Med. 2008 Jan;42(1):42-6. Epub 2007 May 25 Br J Sports Med. 2004 Jun;38(3):285-8. Periodization Training for Sports, 2nd edition: Bompa Et al, Human Kinetics, 2005 J Strength Cond Res. 2008 May;22(3):773-80.
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Conclusion
Football Training: combining agility training and fitness workouts to improve performance Football conditioning to maintain and improve performance Pre match warm-up drills and exercises are a commonplace sight in football but are these drills making the footballers better at what they do, or are coaches merely replicating past practice or advocating what they did as a player years ago? More generally, do the technical training and exercise routines reduce the risk of injury and enhance the players’ performance on the field, and can they be made better? James Marshall investigates
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Research on professional women football players in the USA compared their performance in matches to that of good players (but not professional or internationals) in the Danish and Swedish leagues and found that the work rate was much higher in the professional players, who covered 33% more distance in their hardest five minutes of a match than the ‘good’ players (1). However, it was interesting to see that following this burst, the next five minutes resulted in a 17% below average work rate, showing that it is impossible to maintain the absolute top work rates. The professionals also ran at top speeds for 28% longer over the match than the ‘good’ players, covering 1.68km compared to 1.33km. The overall distance covered was between 9-11km with over 1,300 changes in activity in the match – an average of one change every 4 seconds! There was also a difference in activity levels between the positions for both groups, with defenders performing fewer sprints than midfielders and attackers and also fewer intervals of high intensity running overall. Fatigue had an effect on both groups, with the professionals running 25-27% less at high intensity in the last 15 minutes of the game compared to the previous five 15-minute intervals. The ‘good’ players performed less work in the last 15 minutes of both halves compared to the previous 30 minutes, highlighting the difference between activity levels of merely good amateur players and professionals.
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Football players have to perform repeated sprints throughout the match. Fitter players will be able to perform these sprints for longer. A less fit player may be faster, but won’t be able to produce that speed when it counts – for example during the last 10 minutes of each half or in injury time.
Small-sided games Small-sided games are often used in training as an efficient way of working on fitness and simultaneously. These consist of games of two versus two, three versus three and so on in a half or quarter-sized pitch that requires all players to work almost continuously throughout the duration of the session. The coach can adjust the game to make it more accurately replicate the demands of matches themselves. But, do they actually allow for maximal bursts of activity in a limited space? A study compared the training activity profiles of elite women football players and also their domestic and international matches (2). While the work-to-rest ratios were very similar, the composition of the activities was different. Matches usually had a period of up to four seconds of high intensity activity (defined as sprinting, striding or
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SOCCER ARTICALS high intensity running) followed by 44-64 seconds of low intensity activity (defined as standing, walking or jogging). This equated to work:rest ratios of 1:13 for attackers, 1:10 for midfielders, and 1:15 for defenders. In international matches, however, there were more episodes of repeated sprints than in domestic competition and training. The average player had performed 4.8 repeated sprints in international games, with each sprint averaging 2.1 seconds and with 5.8 seconds of active recovery between the sprints. This type of repeated sprint activity wasn’t found in the small-sided games in training, so clearly they were not helping to prepare the players as well for international matches as for domestic matches.
Having assessed the levels of activity required in football, how do we know if players are fit enough to play at the highest level? Any test has to be able to measure a fitness parameter that is used in football, and also to distinguish between good and very good players. These fitness tests may be useful to see if the player is fit enough but lacks skill, or is skilful in training but lacks the ability to produce that consistently throughout the game. Some researchers are now trying to integrate skill work into the fitness tests to try and separate the different levels of ability more accurately. The advantage of this is that it becomes more specific to football; the disadvantage is that when you are testing more than one variable at once, it is harder to discern which is the weakest point that needs to be trained – skill or fitness. One group of Serbian researchers used a zigzag run test without a ball and then one when dribbling a ball (3). The course was series of four 5-metre sections set out at 100-degree angles (see figure 1 below). The smaller the gap between the two times indicated a higher level of skill and was known as the ‘skill index’. This allows the testers to identify the quick players with the ball, and then see whether less quick players need to work on speed, or skill level.
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Testing
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Training speed or agility It’s quite common to see football coaches do generic speed or agility work using various pieces of equipment on the ground as aids to their training. However, whether this works or not is debatable; it looks good, it’s easy to do, but is it transferable to the sport of football itself? The problem is that most agility tests identify how quick a player moves around obstacles or between two or three different cones. They don’t identify how a player reacts to a stimulus that actually occurs in the game. A good tennis player therefore may do well on a football agility test, but that doesn’t mean he can play football!
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To illustrate this, researchers looked at speed and agility for six random intermittent dynamic type sports: football, field hockey, rugby, basketball, tennis and netball (4). They tested players before and after three training protocols using the T-Test, a 15metre sprint, a countermovement jump and a dynamic balance test. The training protocols used were based on either programmed agility movements, random agility movements in the form of small-sided games or a control group with no conditioning. The programmed group was further split into two subgroups, with one subgroup using specialised equipment while the other didn’t (see box 1). The trials ran over six weeks with training being split into two separate 60-minute sessions a week, including a 15-minute warm up. The subjects involved in this study were untrained, so the results may not be transferable to trained athletes. Both training groups improved their performance over the six weeks, with the programmed group improving more than the random group. There was no difference within the programmed group between subjects who used equipment and those who didn’t.
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As well as the subjects being untrained (where any type of training will normally lead to an improvement) another limitation of this study was that the tests themselves were programmed tests – ie the subjects knew exactly where to go and in what order, so programmed conditioning may well be more suitable for doing better at these tests. Moreover, the group who played the games were also improving their ball skills and game awareness concurrently, and this was not measured.
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SOCCER ARTICALS One study that did look at trained professional football players used either strength or strength and plyometric training plan to improve sprint and jump performance over seven weeks(5). One group of players performed the strength-only sessions, which consisted of half squats performed at 4-6RM (the maximum amount of weight that could be lifted safely either four, five or six times) for three to five sets. The other group completed the same strength sessions but also performed various plyometric exercises such as leg bounds and hurdle jumps.
Pre-season conditioning Most studies done on football players conditioning are short in nature, normally six to eight weeks, because there’s only limited time available to implement new tests and protocols out of season. However, the longer-term effects of training plans and protocols will differ as players continue to adapt. Similarly, if some maintenance work is not done each week, the effects of a pre-season training programme may not last beyond Christmas. Footballers often talk about being ‘match fit’ but that maybe should read ‘match fat’ as evidence shows that just training and playing football may result in greater body fat levels at the end of the season than at the beginning (6)! The same trend has also been demonstrated in rugby league players who recorded increased fat and reduced aerobic and muscular power at the end of the season compared to the beginning (7).
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Both groups improved their leg strength and their sprint and jump performances. The rationale behind the study was that strength training has been shown to improve high force, but not necessarily high velocity. The plyometrics were designed as part of a power programme to help improve force production at speed, which translates into linear sprint speed and vertical jump ability. The authors concluded that players who were also doing football specific training sessions gained no further benefits by performing additional plyometric work – possibly because the football training sessions were already specific enough to aid in increasing the rate of force development.
A study carried out at Texas A&M University looked at a female varsity football team and measures of VO2max, body mass and body fat % through a one-year cycle (8). Despite their season only being 15 weeks long, the players’ average VO2max decreased from just over 49mls/kg/min to 44.9mls/kg/min while body fat increased from 15.7% to 18.8 %! The difference in the training schedule from pre-season to in-season to off-season can be seen in table 1. The main difference was the elimination of the high-intensity speed sessions during the season and also the reduction of weightlifting volume by 35%, with no increase in load. The emphasis during the season was on maintaining the cardiovascular workouts (presumably to maintain VO2max and keep body fat in check) but these did not have the desired effect.
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Although there are no comparable studies in elite footballers, extrapolating these results to a typical European season (which lasts over twice as long) suggests that inseason detraining may be even more of a problem. Indeed, this effect has been observed in a longer season in junior reserve team players (10 to 14 year olds) who gained fat and were slower at the end of the season than the start (8). Caution is needed when looking at data in this age group as maturation levels play a big part in changing physiology, but the decline in performance can be linked to lack of an inseason training plan.
Take home message So how do you plan your training programme? Time is a factor and part-time clubs obviously have less. I would recommend the warm-up as the ideal place to work on the technical aspects of agility, rather than the standard jog around the pitch. Also, the agility drills must replicate the movement patterns of football, and not just be comprised of equipment obstacle courses that distract from the purpose of training. Here are some tips:
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Maybe the coaches believed that matches and cardiovascular training sessions would be enough to maintain fitness. However, as we saw in the study of small-sided games (2), while matches and cardiovascular training can have many benefits, the necessary high-intensity work to maintain peak performance may be missing. By dropping the volume of weight lifting and eliminating the high-intensity speed workouts, the players effectively became detrained as the season went on.
 A combination of programmed and unprogrammed agility sessions, leading into
small-sided games will give players a sound aerobic base and incorporate skill work;  These should be combined with higher intensity quality work for speed and also anaerobic power;  Weight training should be conducted in the off-season with squats being a key lift, to develop lower body power and speed; In-season work should also incorporate shorter sessions of weight training and sprints, but with high levels of intensity. Coaches and researchers often have a particular approach, which they firmly believe in and will often go to great lengths to prove or justify these beliefs. However, it seems that all aspects of training can work to some extent, but also have their flaws,
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SOCCER ARTICALS and that detraining is a common factor during the season. It is therefore important to vary the types of training to prevent staleness and also to maintain intensity and quality work throughout the season. This will ensure that the players are as fit at the end of the season as they were at the beginning.
Football training: improve your speed, power and strength What can you do to achieve optimum condition? Conditioning for football has travelled light years in the last decade. Clubs are determined to get as much out of their multi-million pound investments as they can. Sports science therefore plays a big part and players are subject to rigorous physiological assessment and testing, As a weekend warrior, you won’t have quite the same back-up team to ensure your football fitness, but what can you do to achieve optimum condition?
Warming up for football
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References 1. JSCR, 22 (2), 341-349 (2008) 2. JSCR, 22 (2) 543-552 (2008) 3. JSCR 22 (4), 1046-1050 (2008) 4. JSCR, 21 (4), 1093-1100 (2007) 5. JSCR 22 (3), 773-780 (2008) 6. JSCR, 21 (1), 48-51 (2007) 7. JSCR, 22(4), 1308-1314 (2008) 8. JSCR 19 (2), 400-408 (2005)
A recent survey indicated that hamstring strain rates were negatively linked to the amount of static stretching that Premiership footballers performed. Basically, the more ‘bend down and touch your toes and hold’ type of stretching exercises they did, the more they were likely to strain their hamstrings in practice and matches. This may come as a surprise, but it shouldn’t, when you consider the physical requirements of football. Players have to make repeated dynamic movements, such as sprints, jumps and turns. Research from Finland discovered that in the course of a season, players could make 3,900 jumps and 7,000 turns. These movements all require dynamic muscular contractions; contractions that have little relevance to those involved in held stretches. Most top clubs now employ dynamic warm-ups, which place a much greater emphasis on active and football relevant dynamic mobility. Professor Angel Spassov is a conditioning expert, originally from Bulgaria, who is now based in the USA. He is a football specialist and has worked with six World Cup squads.
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SOCCER ARTICALS The professor has put together a specific football warm-up. You should use and adapt it to your purposes, if you want to avoid crying off with injuries that could be avoided. Spassov’s warm-up involves both passive and active (dynamic) elements. For the passive part, he advises players to loosen their muscles 30-60 minutes before the game/training session, by rubbing their ankles, knees, all the leg muscles, lower back, neck and shoulders with a heating ointment, preferably one that is odourless and not too hot on the skin.
The active warm-up is divided into two parts: 1. General.
Next, the legs (hamstrings, hip flexors, abductors, adductors, quads and calf muscles) are targeted, with passive (held) and dynamic stretches (two to three standard routines with 10-12 reps, with performance speed increased every set for the dynamic stretches, such as leg swings). Next, varying-intensity sprints are performed in different directions. At the end of this general part of the warm-up, players’ pulse rates should have reached 160-170 beats per minute.
2. Specific.
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This begins with six to eight minutes of jogging, followed by neck, shoulder, lower back and abdominal stretches. There should be two to three different routines, with 10-12 repetitions of each.
This begins with various kicks of the ball with both legs, and various technical moves with the ball, such as dribbling and stopping the ball. These should progress to medium intensity and be performed with another player, then to high intensity, with players combining into groups to practise all the technical skills at the highest possible intensity and speed. Spassov’s suggested warm-up makes great sense and should control players’ progression to match readiness. With the early parts of the warm-up performed individually, players should be able to focus on their own movements and progress and not be tempted to perform too-dynamic movements before their muscles are fully prepared.
Football speed All players require speed. Everything else being equal, the faster you are, the better player you will be. However, football speed is different to the speed required of a
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SOCCER ARTICALS sprinter. 1. Football speed is reactive and often unpredictable 2. The first step (linear or rotational) makes all the difference to getting past an opponent or close enough to make a winning tackle. 3. A skill will often be have to performed from the basis of speed – tackles, headers, passes, shots and so on. 4. Although elite players play on pitches that could support a game of bowls, many of us will not be so lucky. Muddy, undulating surfaces will impair speed generation.
Your training must reflect the above considerations. Use the following practices to improve your speed:
1. Turn and sprint drill Players stand on the halfway line; at a command, they turn and sprint 10m. Repeat six times, taking 30 seconds’ recovery time between efforts, while varying the turn direction.
2. Run and dribble intervals
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5. A sprint may be needed when you’re ‘blowing hard’ (see Developing football endurance, on the next page).
Run at three-quarter pace to a ball placed 20m away. Dribble it and swerve around a cone, and pass after a further 15m. Jog back and repeat six times.
3. Speed dribble ‘Speed dribble’ over 30m (from standing: simply dribble as fast as you can, in a straight line). Repeat six times, with one minute’s recovery time between each effort.
4. Floor/speed ladder drills You may have seen players performing various drills through floor/speed ladders on TV (you can also see these types of drills being performed on Peak Performance Premium – search: speed, agility). These exercises are designed to improve, speed, agility and reactive ability. They will positively affect your neuromuscular system if used over time, so that you will be able to get your legs moving that bit quicker. There are
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SOCCER ARTICALS hundreds of permutations that can be used with one or more ladders. Here are some examples: i) One foot in each rung (use a low knee lift and concentrate on foot speed, driving your arms backwards and forwards). ii) Step sideways through the ladder. Keep low and light on the ground. iii) Run backwards through the ladder one rung at a time – use your calf muscles and ankles to generate your speed and don’t forget to co-ordinate your arms with your legs.
Developing power for football Footballers are athletes in every sense of the word. All will resistance train. Their training plans will involve body weight, weights and plyometric (jumping) exercises. Weight training will provide foundation strength for more specific football condition, such as speed, to be built on.
Key weight-training exercises for football include: Squats, lunges, leg extensions and leg curls – with the latter, concentrate on the lowering (eccentric) phase of the movement to reduce potential hamstring strain. Lift a medium to heavy weight (70-80% of 1RM) using 6-10 reps, over two to four sets. Everything else being equal, a larger muscle will be more powerful and enduring.
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iv) As i), above, but on exiting the floor ladder, take control of a ball, dribble 10m round a cone and speed-dribble back to the start.
Can weight training make you a net buster? Research has indicated that improving kicking power directly through weight training or other means is unlikely to produce positive results when it comes to greater kicking power. You will get greater returns by working on your technique. However, greater muscle power can significantly improve other aspects of play, such as your leap, sprinting and injury resilience.
Bodyweight exercises The dreaded ‘burpie’ (squat thrust with jump at the end) still has a place in football conditioning, as do other body weight moves, such as press-ups and sit-ups. Put them
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SOCCER ARTICALS into a circuit that lasts (with recoveries) 20-plus minutes and also contains ball skills and you are onto a winner. Incorporating ‘keepy uppy’ and short distance passes between players in a circuit will condition specific power and skill endurance – the ability to perform a precision skill under conditions of fatigue is crucial for football players.
The core Pay particular attention to core strengthening exercises, such as crunches and ‘chinnies’ (alternate knee to elbow sit-ups), hyper (back) extensions and the plank. A strong and dynamic core is required to maintain player solidity on the ball and reduce injury.
Sit on the floor with knees bent to a 90-degree angle as per normal sit-up. You’ll need a partner who should carefully toss a football toward you as you reach the top of your sit-up. At this point you head the ball back to him. You then control the descent of your body as it returns back to the floor. Complete 10 reps over 4 sets swapping positions with your partner.
Football-specific circuit Perform on a ‘20 seconds on, 30 seconds’ off basis
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Football-specific core strength exercise: sit-up with header
Press-ups, squat jumps, crunch, keepy-uppy, simulated headers (alternating left, double, and right foot leaps from a static or one stride approach), the plank, wall passes over 10m, alternating left to right foot strikes, burpies, chinnies, single leg squats, sit-ups with header (see above)). 10m sprints (back and forwards), floor ladder drills.
Developing football endurance Forget the 10-mile runs – football is an anaerobic (stop/start) activity. You’ll be much better off performing various pace running repetitions over distances from 10m to 100m, with short recoveries. Some workout examples: 1. Twenty minutes of jogging, sprinting, walking and half-speed and three-quarter paced runs. Coach (or fittest player taking part) determines the distance to be run and the recovery by calling out, for example: ‘20m sprint; walk 15m; 40m three- quarter pace run; jog back’ and so on. This drill should be contained within one half of the football pitch.
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SOCCER ARTICALS 2. Pass and sprint drill. Two players stand 10m apart. They perform 20 alternate left to right leg passes and then turn in opposite directions to sprint 10m round a cone and back to the start position to perform another set of passes. Take 30 seconds’ recovery and repeat five times. 3. Players perform 20 press-ups and 20 squats on one goal line, jog to centre circle to collect the ball, sprint dribble toward the other goal and then shoot from just outside the penalty area (keeper optional). Repeat five times, with jog back recovery between efforts.
Sports Coaching: coaches should rely more on sport science than sports trends Coaching has always been something of an art Coaching has always been something of an art. But in a thought-provoking article, Tom McNab argues that many coaches should pay more heed to science and less to following the latest trends… Extraordinary Popular Delusions and the Madness of Crowds should be obligatory reading for all coaches. It was written by Charles Mackay back in 1841 and details the various crazes that have afflicted mankind over the centuries. Among those discussed are The South Sea Bubble, Tulipomania, and the Crusades. Indeed, the list of lunacies to which mankind has at some time subscribed is a long one!
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Use these practices and drills in your pre-season training and maintain your fitness with them in-season, and before long you’ll be challenging for the title – whatever your level.
Athletics, and in particular running, has not been immune to such delusions. Prior to the practice of coaching, and in its early years, this was both understandable and excusable, because science had not yet been extensively applied to sport. However, it is less excusable now, especially when some degree of scientific scrutiny can be applied to each new technique or training method.
Past (and present) delusions It might be worthwhile to cast our eyes back to history to consider some past delusions and some that are still in vogue today (see boxes 1-8). Now, not all of these ideas were totally misguided; some simply represent misapplications of valid training methods. However, I hope that they might, in their totality, put in perspective some of the flabby thinking that has often invaded some recent coaching methods.
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SOCCER ARTICALS As I said at the outset, not all of the methods described here have been discredited. Some (like interval training and 100 miles a week) were simply misused or misapplied. Some, like circuit training (though of some value for the unfit) must be seriously questioned as a means of training for mature athletes. And some, like speedball, are just plain daft! The problem is that all have been at some time accepted as Holy Writ, and this of course begs the question of how many of our present widely accepted training methods will stand up to serious scientific scrutiny.
It is, I believe, possible to determine which course a coach has attended by the drills he presents to his athletes a week later! The big toe drill, the left eyebrow drill, a drill for the index finger devised by Professor Alucard of Transylvania University – any or all of these can be adopted by coaches simply because that drill has become the current orthodoxy. In very few cases are these drills subjected to even the slightest scrutiny. This is often because coaches believe they must surely be right – they are after all being proposed either by an ex-international or by the coach of a prominent athlete! Thus, within a week after any course, various mutations of these drills surface all over the place, many as different from what were originally demonstrated as I am from Hercules! At this point I should raise my hand and plead guilty; I have for years used and developed the running drills of the late Bud Winter (former US Olympic track coach). Indeed, these drills helped to take British 100m runner Greg Rutherford from around 11.50s to 10.38s in two years. But then these were not isolated drills taken out of the event, but focus-drills that all were practiced within the skill of running itself. Effective drills are all about transfer of training and might therefore better be called ‘related practices’. Assuming it’s valid and practised within the skill of the sport itself, to be effective any drill must be applied within the full movement as soon as possible if there is to be successful transfer. However, what is more often observed on the training ground is ‘drilling’, with athletes of widely varying abilities, and all for some reason doing the same number of repetitions, but in isolation, with no early transfer to the event itself!
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Drills training transfer
There is ample precedent for this type of activity. I well remember land drills, deployed as late as the 1950s as a means of learning to swim. The fact that, when I was placed in the pool, I was still quite unable to swim bothered my teacher not a jot. He had taken me through the drill. The fact that I could not swim was my fault!
Football drills Let’s take a look at football, where the Dutch coach Coerver has devised a series of ball drills for children. These include the ‘Cruyff step-over’, the ‘Ronaldo shuffle’ and many others. However, Coerver tries to put these mini-skills into two against one and small team games as early as possible, in order that there is effective transfer.
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SOCCER ARTICALS Without that, they remain sterile drills with little practical value. All of this is not to deny that most drills have some value. What I’m hoping to do here is to question the amount of time spent on them, (particularly with beginners), to stress the need to secure transfer, and the importance of subjecting each new drill to rigorous technical scrutiny. Each moment we spend with an athlete must have a justifiable purpose and measurable benefits. It is said that the discus thrower Wolfgang Schmidt of the former East German Republic admitted that, although he described dozens of discus drills to coaches eager to learn new techniques, he only ever used two of these drills himself. His explanation was that he was only providing what coaches wanted to hear, and what they wanted was to return to their athletes with a fresh set of drills!
The ‘good old days’ are usually only evidence of bad memory. But in the past, national coaches tended to act as a filter for any new ideas. Now, however (in the UK at least), the link between our voluntary coaches and practical international level coaches who are capable of subjecting new methods to some degree of rational scrutiny has gone. But there is no good reason why coaches cannot create filters of their own by subjecting new and fashionable drills and trends to good old-fashioned scientific scrutiny. This being said, it is important to repeat that coaching is not a science, but rather a practical art – it is how we deploy scientifically tested methods that will determine our success as coaches. But someone or something must surely be created to protect us from another speedball and to evaluate Professor Alucard’s index finger drill!
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Summary
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Football Training Drills for Improving Energy Systems During Pre-season Football Tips and Exercises to Make You Ready for the New Season Article at a glance:  The energy requirements of football are outlined;
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SOCCER ARTICALS The principles of pre-season training are discussed, particularly the importance
of skills-based fitness training; Examples are given of these principles applied in practice.
‘I wouldn’t say pre-seasons are a lot easier now but they’re a lot better,’ says the Villa striker. ‘All I can remember is you didn’t get to see a ball for four or five days. As soon as you reported back for training it was straight into running morning and afternoon. I think if you asked a lot of older players, they would say that’s exactly what it was like. The difference nowadays is that you see the ball right away, the first day. Yes, we still do running but it’s not so intense, pounding the roads for a couple of hours. It’s a hell of a lot different.’ Kevin Philips, Aston Villa striker, 2006 Sports science and modern technology has had a major effect on football training over the past 10 years. Many teams have become much more analytical about their players’ work rate in games, and also in training, by introducing tools such as game analysis and heart rate monitors, in order to gain an accurate understanding of the physical demands of players in games. The structure and training methods in football throughout the season have also changed significantly and the period of pre-season training has seen some of the biggest and most significant changes, due to the importance of ensuring that players starting the season are in the best possible shape, and the need to maintain their fitness throughout the season.
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Effective pre-season football training is not just about running around the football pitch in order to shed those off-season pounds. According to Jim Petruzzi, a much more scientific approach is needed, which combines energy systems training with skill development
Gone are the days when players would report to pre-season training and told they would not see a ball for two weeks. Small-sided games and ball-related exercises now comprise a major part of training within the modern professional game. A perfect example of this was the preparation that the Korean team (widely acknowledged to be one of the best prepared teams in the tournament) adopted in preparation for the 2002 World Cup finals. In a review, Verheijen described how initially the Korean players could not maintain their desired pace for the full 90 minutes(1). Players made high-intensity runs less frequently and there were fewer ‘explosive actions’ as the second half progressed. After a systematic training programme, they were able to maintain a higher tempo for the entire match and the recovery between explosive efforts was dramatically improved.
The energy requirements of footballers 44
SOCCER ARTICALS Football incorporates periods of high-intensity efforts interspersed with periods of lower-intensity exercise. The physiological demands of football require players to be competent in several aspects of fitness, which include aerobic and anaerobic power, muscle strength, flexibility and agility.
Jargonbuster Alactic the energy pathway which permits athletes to work at very high intensity for over 10-15 seconds without lactic acid production or the use of oxygen Figure 1 below illustrates an actual heart rate plot from a professional footballer using a heart rate monitor taken during a pre-season game; notice the continuously varying heart rate but with high average peak values. Figure 1: Actual heart rate plot of professional footballer
Date and Time
15/07/2006 14:12
Duration
3:07:30.0
Heart Rate Average
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Overall, the game of football is essentially aerobic with intermittent anaerobic and alactic bursts of energy. Outfield players average heart rates of about 160bpm during football games and operate at 75-80% of their maximum oxygen uptake (VO2max), which is comparable to marathon running. However, football is not characterised by steady heart rates of 160bpm, which are sustained for 90 minutes of play; heart rates are continually fluctuating depending on the nature of the activity the player is performing.
153 BPM
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SOCCER ARTICALS Running
Selection (red bar)
0:27:30 – 3:05:25 (2:37:55.0)
Heart Rate Maximum
190 BPM
At the professional level, the contemporary game of football seems to be more demanding than suggested in much of the early literature(2), which therefore suggests a more systematic approach to training is needed(3).A comparison of the work rates of English Premier League players over two seasons (1998-1999 and 1999-2000) with previous observations of top English League players before 1992 shows that today’s players cover approximately 1.5kms more ground in a game than their earlier counterparts(4) – a difference that is apparent for all the playing positions.The data for the 1997-98 season shows that compared with the 1991-92 season, there is also evidence of a faster tempo to the game, including more movement of the ball and shorter breaks in play. This is probably partly due to changes in the rules, such as the omission of the back pass and also advances in sports science and player conditioning.However, despite the high aerobic demands necessary to sustain work output for 90 minutes, games are often decided on the quality of explosive efforts, which depend on anaerobic and alactic bursts of energy; for example, to get to the ball first, leap above an opponent, spring into a goal-scoring position or to close down an opponent and deny them space to pass or shoot at goal.The simulation of the exercise intensity corresponding to match play has enabled sport scientists to study a number of aspects of play under laboratory conditions. Observations highlight the value of exercising with the ball where possible, notably using activity drills in small groups. Small-sided games have particular advantages for young players, both in providing a physiological training stimulus and a suitable medium for skills work. While complementary training may be necessary in specific cases, integrating fitness training into a holistic process is generally advisable.
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Sport
Principles of pre-season training A successful pre-season programme is one that incorporates all of the necessary components to enable players to maximise their performance as soon as the season commences, and to be able to sustain peak physical condition throughout the season. These fitness components often vary with the individual player, the positional role in the team and the team’s style of play. Other considerations include the physical demands of the game, the current level of fitness of a particular player and what the team is striving to achieve. To meet these requirements, a well-designed pre-season training programme that addresses the specific demands of each footballer is a must. Because of this, it is worth considering physical and physiological tests at the start of your pre-season schedule to see how the players are doing, and to evaluate their preparation plans. These tests give information on the levels of endurance, speed, muscular endurance, strength, coordination, technical, and tactical elements during the preparation period.”A successful pre-season programme is one that incorporates all of the necessary components to enable players to maximise their performance as soon as the season commences“A pre-season preparation period covers the period
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Adapting these games to meet the physiological demands of football is important. Football is played by two teams of 11 players performing in an area of approximately 100m by 60m. However, during training, it is common practice to reduce both the number of players on the pitch and the size of the pitch, which has the effect of increasing the proportion of anaerobic/explosive work required. These small-sided games are one of the most common drills used by coaches in football training; whereas in the past small-sided games were mainly used to develop the technical tactical abilities of the players, they are now being employed by amateur and professional teams as an effective tool to improve physiological aspects of the game(6).
Changing approach to conditioning Although it’s true that footballers cover large distances during a match, it’s important to note that football players are continuously alternating between anaerobic and aerobic activity, which allows recovery to take place. As a consequence, football is characterised by one dominant energy system in the body (aerobic) but with the two other energy systems (anaerobic alactic and anaerobic lactic) that enable higherintensity outputs to play a vital role. Training all three energy systems, therefore, is important.
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from the beginning of team training until the first official match. The length of these training periods may differ from one country to another. During this training period, physical conditioning should be composed mainly of games and exercises with a ball. The frequency and number of training sessions should be increased gradually as the season approaches(5).Paul Aigbogun, coach of the San Francisco Seals team, speaks of some of his favourite practices demonstrating how the ball can be incorporated into training for physiological benefits: ‘Some of my favourite practices are crossing and finishing, keep ball, building up to a small-sided game, starting at 1 v 1, building up to 2 v 2, 3 v 3, 4 v 4, probably up to a maximum of 8 v 8. Another one of my favourite practices is attacking team play, 11 v 6’.
Jargonbuster Anaerobic lactic Short duration (1-2 minutes) high-intensity energy pathway involving the breakdown of glycogen (glycolysis) in the absence of oxygen, with the formation of ATP plus lactic acid Traditionally, footballers have used interval training to develop aerobic fitness. However, the use of small-sided games has recently been recommended as an ideal training method for improving fitness and competitive performance in football, because match-specific small-sided games can effectively improve the fitness of the cardiovascular system while mimicking match-specific skill requirements(7,8). Other advantages include increased player motivation, training the capacity to perform skilled movements under pressure and a reduced rate of training injuries.
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SOCCER ARTICALS Scientific research has established that five-a-side football drills on a pitch measuring 50m x 40m can produce heart rate responses within the intensity range previously shown to be effective for improving aerobic fitness and football performance (performing running interval training at 90 to 95% of maximal heart rate)(9).
Pre-season anaerobic training – One approach is to work on general anaerobic conditioning using quality interval training, which can be performed by performing football-related activities. In practice, that means alternating maximum speed sprints with very light jogging or walking. Workouts should last about 20-30 minutes and consist of 7-10 second sprints and 30-50 seconds of low-intensity jogging or walking, giving an aerobic/anaerobic training ratio of 5:1. For example, you could play 1 v 1, where one player is defending a goal on the edge of the 18-yard line. The other player sprints at full pace from the other 18-yard line, receives the ball on the halfway line and sprints towards the goal aiming to get a shot on target. He then jogs backs and repeats the same drill. Summary of energy Systems in football: 1. Anaerobic alactic, high intensity. Duration up to 15 seconds; used in explosive efforts and short sprints, kicking, tackling etc; 2. Anaerobic lactic, moderate-high intensity. Duration of 15-120 seconds; used in longer sprints and sustained high-intensity efforts (heart rate around 90% of maximum); 3. Aerobic moderate to low intensity 120 seconds plus used while jogging, walking, recovery between harder efforts etc. Aerobic activities
Anaerobic activities
Walking Walking backwards Jumping Jogging Running at speeds less than ¾ maximum pace
Most tackling and contact situations Accelerating and changing direction quickly Running at speeds greater than ¾ maximum pace
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Examples of principles in practice
An example of this was a training drill that Bansgo conducted with Zambrotta while he was assistant coach at Juventus. The drill was for Zambrotta to play the ball from the edge of his own box to a midfielder, sprint and then receive the ball inside the opposite half and run with the ball, cutting back inside and striking it with his left leg. The aerobic/anaerobic training ratio was 5:1 – ie very specific to football.Pre-season speed training – Here’s an example of a speed drill that combines skill and fitness training. Divide the players into two equal groups, placing them both in a single line
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Constructing a football-specific pre-season training sessionThe following is a guide you can use to help you plan your own pre-season training sessions. As well as simple running drills, you can also incorporate the relevant work/rest/intensity combinations into football-specific drills. Speed
Exercise (secs)
Rest
Intensity
Repetitions
2-10
5 times exercise duration
Maximal
2-10
Building speed/endurance
Exercise (secs)
Rest
Intensity
Repetitions
20-40
5 times exercise duration
Almost maximal
2-10
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formation, and have the two players at the front of the two groups facing each other at a distance of about 20 metres apart. Player A (the player at the front of the line) from group one passes the ball to the other player A (the player at the front of the line in group two) and sprints to the other side to the back of group two. Player A from group two receives the ball, controls and passes the ball then sprints to the back of group one. Each player repeats this with the emphasis being on speed. After passing the ball, it should take about 3 seconds for the player to sprint 20 metres, with a short rest before performing the exercise again.Pre-season aerobic training – Examples include drills lasting 2-3 minutes with a work/rest ratio of 1:1 working at low intensity or continuous low-intensity work over a period of 20 minutes. Alternatively you could play a small-sided game such as 4 v 4, though if you wanted to work solely on the aerobic system, these games would need to be played at low intensity to keep aerobic activity to a minimum.
Maintaining speed/endurance
Exercise (secs)
Rest
Intensity
Repetitions
30-90
30-90 seconds
Almost maximal
2-10
Intensity
Repetitions
Aerobic high intensity
Exercise (mins)
Rest
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Same as exercise duration
90%+ of heart rate maximum
4-6
Exercise (mins)
Rest
Intensity
Repetitions
8-10
1-2 minutes
70-80% of heart rate maximum
2-4
As a rule of thumb, training should involve regular use of the ball wherever possible as this will not only help develop the specific muscles involved in match play, but also improve technical and tactical skills and help keep players interested. This is where small-sided games offer an advantage and many coaches such as Marcello Lippi, formerly at Juventus, and winner of the 2006 World Cup with Italy, are big believers in the positive effects of small-sided games.
SummarySmall-sided games and football-related activities, as highlighted, have a number of benefits. Footballers love nothing more than to play football, and while the physiological aspect of football is one of the most important factors in players performing at their best, incorporating functional activity, small-sided games, and football-specific activity is bound to make sessions more enjoyable for the players while improving their physical fitness to meet the demands of the game. Jim Petruzzi is a performance coach, specialising in sports science and sports psychology, who works with several professional football clubs and international teams
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Aerobic low intensity
References 1. Verheijen Conditioning for Soccer 2003; 1/275-276 2. Insight – The FA Coaches Association Journal 2004; 2(7):56-57 3. Journal of Human Movement Studies 1976; 2:87-97 4. J Sports Sci Med 2001; 6:63-70 5. Acta Physiol Scand Suppl 1994; 619:1-155 6. Br J Sports Med 2002; 36(3):218-221 7. Balsom, PD. Precision Football. Kempele, Finland. Polar Electro Oy 1999 8. Sports Coach 2002; 24(4):18-20 9. Journal of Sports Sciences 2000; 18:885-892
10.Ankle injuries are more common than hamstring tears in footballers 10.
Ankle injuries can be tackled by proprioception training 50
SOCCER ARTICALS 11. Contrary to popular belief, it’s not hamstring tears but ankle injuries that are the most common injury in footballers. And when footballers do sustain ankle injuries, there are three common treatment strategies employed to help prevent reoccurrence; strength training (to strengthen muscles and ligaments that stabilise the ankle), orthotic inserts (placed in the shoe to try and place the foot in a more ‘biomechanically neutral’ position and so prevent injury) and proprioception training (which mainly involves balance training and enhancing the ability of the ankle/foot structures to respond to and control external forces).
13. * Strength training; * Orthotic use; * Proprioception training; * Control group (no intervention). 14. The players were then monitored for the rest of the season, during which data on the frequency of ankle sprain re-injury data were collected. There were no significant differences among the groups in the number of exposures (ie all the groups were exposed to the same degree of injury risk in terms of time, matches played etc), but the incidence of ankle sprains in players in the proprioception training group was significantly lower than in the control group. However, while the risk was also reduced in the strength and orthotic groups, the reduction was not large enough to be considered statistically significant and the researchers concluded that only the proprioception training group showed a significant reduction in rates of re-injury. Of course this is not to say that strength training and orthotics don’t have benefits; many rehab programmes use a combination of strength and proprioception training – something not assessed in this study. It does suggest however, that proprioception training is a crucial element in the prevention of ankle re-injury. Am J Sports Med 2007; 22 [Epub ahead of print]
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12. But which of these three single interventions is most effective at reducing the incidence of further ankle injury? That’s the question that Iranian researchers have been trying to address in a study on 80 male footballers in the first division of a men’s league who had all experienced previous ankle inversion sprains. The players were randomly assigned to one of four groups, each of which contained 20 subjects:
Head injuries in Football No long-term risk from concussion in football Football Injuries to the head Multiple concussions do not damage footballers’ brains: that’s the encouraging conclusion of a new study from Australia, which directly contradicts the findings of previous research. Earlier studies had suggested that footballers with a history of
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SOCCER ARTICALS concussion show cognitive (thinking) impairment by comparison with athletes with no such history. In the current study, 521 male Australian rules footballers completed a brief medical history questionnaire and then performed a series of six cognitive tasks assessing reaction time, decision-making, attention, learning and memory. For analysis purposes, the athletes were divided into five groups, as follows: No history of concussion (244 subjects); One concussion (95); Two concussions (72); Three concussions (48); Four or more concussions (62).
The researchers found no association between the number of previous concussions and performance in the cognitive tasks. ‘Evidence based reviews of the literature suggest that sustaining several concussions over a sporting career does not necessarily result in permanent neurological damage or increased risk of future concussion,’ the researchers point out. They conclude: ‘These findings support the current consensus management guidelines proposing that return to play should be determined by clinical evaluation of the individual athletes rather than by categorisation of the athlete according to their selfreported history of concussion…’ Br J Sports Med 2006; 40:550-551
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Football players' balance is inferior Comparison of standing balance in dancers and football players Could dancing and soccer technique be comparable? The possible benefits of dancing for developing athletic balance and agility were discussed by Peak Performance recently. Now a new US study on dancers and footballers appears to provide further confirmation of these benefits. Thirty two female collegiate soccer players were compared with 32 dancers for a number of measures of standing balance using ‘centre of pressure’ measurements, which involved balancing on a special pressure sensitive mat while the following were recorded:
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upright); The centre acquisition time (the time required to achieve vertical balance after performing a movement); The sway path length and velocity. The results showed that while the scores from 15 of the 20 balance tests were not significantly different between the two groups, the dancers achieved superior scores in the other five tests. The Harvard Medical School researchers went on to conclude that: ‘Dancers have certain standing balance abilities that are better than those of soccer players,’ and also that ‘the COP measurements in this study can be used as a tool in future studies investigating standing balance in different groups of athletes.’
Hamstring injuries: A Study Surgical treatment of partial hamstring tears, a common hamstring injury, is successful in most cases, even after conservative treatment has failed. That’s the encouraging conclusion of Finnish researchers, following the largest study of hamstring injury surgery to date, focusing particularly on soccer training. Forty-seven athletes – 32 men and 15 women – with partial hamstring tears had surgery to repair the damage over an 11-year period between 1994 and 2005. They included 13 international-level professional athletes, 15 competitive-level athletes and 19 recreational athletes from a variety of sports, most commonly football. Forty-two of the patients had been treated conservatively, with unsatisfactory results, and the remaining five had been offered surgery shortly after sustaining their injuries. Ten of the 28 professional and competitive level athletes continued to take part in their sport before surgery but complained of pain, weakness and impaired performance. The other 18 athletes were prevented by their symptoms from performing at all.
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Hamstring injury solution?
The surgical treatment involved reattaching the torn tendons to their point of origin in the athletes’ legs. They had to use an elastic bandage for one to two weeks afterwards and were allowed to begin partial weight bearing within two weeks and full weight bearing after two to four weeks. Follow-up over an average of 36 months showed excellent results in 33 cases (70%) and good results in nine (19%). The best news was that 41 of the athletes (87%) were able to return to their former level of sport after an average of five months. Hamstring strains and tears are common, potentially disabling and even careerthreatening in some cases, the researchers point out. ‘According to our results, it
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SOCCER ARTICALS seems that excellent or good outcomes may be expected after surgical repair in most cases of partial proximal hamstring tear. However, surgery is technically easier in the acute [early] phase. If conservative treatment is chosen, the possibility of surgical treatment should still be kept in mind,’ they conclude, ‘especially if the symptoms are prolonged.’
Football 'Throw-ins': Attaining maximum distance Being able to throw the ball large distances from the touchline confers an obvious advantage in football, especially if the ball can be propelled into the region of the opponents’ goal area. But while some football players are renowned for having long throw-ins, what does the science say about maximising thrown-in distance generally? A team of British scientists has been trying to answer exactly this question by studying maximum-effort throws using videography. In the study, a male football player performed maximum-effort throws using release angles of between 10 and 60 degrees (the initial inclination of the path of the ball as it is released from the hands). These throws were then analysed using two-dimensional videography and the player’s optimum release angle was calculated by substituting mathematical expressions for the measured relationships between release speed, release height and release angle into the equations for the flight of a spherical projectile. The result indicated that the musculoskeletal structure of the thrower’s body has a strong influence on the optimum release angle. In the study, using low release angles helped the player to release the ball with a greater release speed; because the range of a projectile is strongly dependent on the release speed, this bias toward low release angles reduced the optimum release angle from 45 degrees (the mathematical theoretically optimum angle for projectiles generally) to about 30 degrees. Calculations showed that the distance of a throw may be increased a few metres further by launching the ball with a fast backspin, but when backspin is applied, the ball must be launched at a slightly lower release angle than 30 degrees!
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Attaining maximum distance in football ‘throw-ins’
Sports Biomech 2006 Jul; 5(2):243-60
Football Player Injuries - Are they becoming more frequent? Football injuries - are they really on the rise?
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SOCCER ARTICALS With the World Cup in full swing, the media has been full of stories about the apparently increasing incidence of injuries among professional footballers. But as TJ Salih explains, the reality is far more complicated than the tabloid headlines would have you believe
During the run up to the World Cup, few can have been unaware of the increased reporting of injuries to high profile footballers. Just 10 days before the start of the tournament, the sporting headlines were full of footballing injury stories. The Argentina and Barcelona forward Lionel Messi was still recovering from a thigh injury, while his fellow countryman and Villarreal centre back Gonzalo Rodríguez had effectively waved goodbye to his chances of going to the World Cup Finals after tearing a ligament in his left ankle. Meanwhile, the Germany and Bayern Munich player, Michael Ballack, was also doubtful due to an ankle injury, as was the Dutchman Rafael van der Vaart of Hamburg, who limped out of training after hurting the same ankle he thought had healed. And with the British media brimming with stories about the fitness or otherwise of Michael Owen and Wayne Rooney, it’s been hard to avoid the conclusion that the overall incidence of footballing injuries is increasing. However, there’s mixed evidence for this. Increased sport participation does increase the risk(2), but on an hour-for-hour participation basis, it is likely that the risk has remained the same (3). The fact that certain injuries can keep high profile players away from the game for months or even years brings particular injuries into the public arena. With this in mind, this article reviews the evidence for injury patterns to the lower limb and spine, the mechanisms of injury, and the trends and possible theories underlying the findings.
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Football is a highly athletic sport with rapid deceleration, acceleration, single-stance twists, single-stance ballistic movements and aerobatic manoeuvres. This may explain why the overall level of injury to a professional footballer has been shown to be around 1,000 times higher than in industrial occupations generally regarded as high risk (1).
Lower limb injuries With the advent of Wayne Rooney’s injury in the run-up to the World Cup, metatarsal fractures have been topical. Rooney fractured the fourth metatarsal in his right foot. This type of injury has also afflicted other international players, such as Edwin van der Sar (Netherlands and Manchester United), Gaël Clichy (France and Arsenal), Ivan Campo (Spain and Bolton) and Paulo Ferreira (Portugal and Chelsea). The high incidence of metatarsal fractures in football players has raised the question as to whether modern football boots offer enough protection to the foot and whether they are to blame for the high number of foot injuries. Indeed, Rooney was wearing a new Nike model, the Total 90 Supremacy, for the first time on the day that he was injured.
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SOCCER ARTICALS Although Nike denies that its boots are linked to a higher risk of injury, Tommy Docherty, the former manager of Manchester United, said that when he was a professional football player in the 1950s, it used to take six weeks to break a pair of boots in and players used to have to put them in a bucket of water (4)!
Another reason why we are hearing more of these types of injury is the terminology now used and the increased reporting of the injury by the media. Tony Book, a former professional UK footballer, told the Manchester Evening News that he believes the name of the injury has changed. He believes the old ‘broken toe’ injury is now reported as ‘fractured/broken metatarsal’ (4). This changing terminology, coupled with increased media reporting, may be giving rise to a perceived increase in the number of injuries. There may not be more metatarsal injuries now than there used to be, but we all certainly know more about them (6). Before MRI scans were widely available, ‘ankle pain’ was common, but now we have various degrees of ‘bone bruises’. Likewise, in 1960, no one had heard of ‘Gilmore’s Groin’, but by 1990 everyone had one! Again, this indicates that with changing times and advances in technology, the terminology changes but the underlying injury does not. The foot and footwear
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The English Football Association also states that, ‘players are ill-advised to start a game having not previously worn the boots they are to play in as it may lead to unnecessary injury’. They also go on to advise how to break in the boots progressively during training sessions prior to wearing them in a match, and concur with the idea that soaking them in water may not be a bad idea(5). The theory here is that the water softens the leather and allows the boot to be broken in faster.
When considering the foot in the context of injury, we have to allow for the position of the foot on the ground, the forces applied to it and the type of grip available (in terms of studs or blades) and any additional support offered by the footwear. Other forces may come into play with the other foot (the non-stance foot), and relate to the instantaneous forces applied to the toes, foot and ankle in kicking the ball, or accidentally kicking or being kicked by another player. Ideally any boot should: 1. provide good grip and traction to allow rapid acceleration/deceleration and change of direction; 2. provide adequate support and stability for the foot; 3. distribute the load and decrease the shock of impact; 4. protect the foot and toes against direct trauma (ball and another boot); 5. be comfortable and flexible (7). The older style football boot with its hard toecap and high sides offered protection to the foot and ankle, but limited the range of motion of both (8). The design of modern
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SOCCER ARTICALS football boots allows the foot and ankle total freedom of movement to provide maximum flexibility to the player. But has the modern football boot succeeded in protecting the player while optimising performance? Also, have the changes led to injuries elsewhere, such as an increased tendency to rupture the anterior cruciate ligament, by virtue of increasing torsion on the extended knee?
It is very easy to blame football players’ ‘tools’, but other factors also have to be taken into account and it is highly unlikely that any single factor is to blame for an injury pattern. It is also unlikely that any single factor could be isolated unless there was a large increase in a particular type of injury in association with a particular boot or playing surface. What the research says Research has identified three main factors that influence the increased likelihood of injuries in football players: Intrinsic factors, such as age, previous injury history, fitness and skill level; Extrinsic factors such as the amount and quality of training, playing field
conditions, equipment (eg boots, shin guards), subjective exercise overload during training and matches; Violation of the rules (foul play) (9).
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The available research on these questions is far from conclusive, as the literature is full of anecdotal and conflicting evidence. Simply looking at the number of injuries to the foot is of little value since the forces on the foot cannot be accurately assessed and the level of play, position on pitch and technique would have to be taken into consideration.
For example, artificial playing surfaces have been implicated in non-contact injuries of the lower limb, such as ruptures of the anterior cruciate ligament. Evidence from research in America has indicated that there may be an increased number of lower limb injuries when playing on artificial surfaces compared with grass (9, 10). Again, however, we cannot simply blame artificial grass, as it appears that variations in shoesurface traction can also account for some injuries(11). This includes ground hardness, dryness, grass cover, grass root density, length of studs on players’ boots and relative speed of the game. It is possible that measures to reduce shoe-surface traction, such as ground watering and softening, and players using boots with shorter studs, may reduce the risk of football injuries (12). Studies have indicated that up to 87% of injuries in football occur in the lower limb (thigh, knee and ankle), with only 38% of injuries involving player-to-player contact (13). With this in mind, non-contact injury mechanisms are under increasing analysis in order to try to minimise and reduce further injuries.
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SOCCER ARTICALS Spinal pain and football Modern football requires exceptional gymnastic abilities in the spine as well as the lower limbs. The spine, in conjunction with the ‘grounded’ foot, provides the stable platform for the mobile foot to kick the ball, or for the head to head the ball.
Considering the number of lower limb injuries sustained by football players, it is surprising that more do not get spinal pain. One possible explanation could be that the selection process for footballers is such that those with back pain develop symptoms early in their career and never reach the status of an elite athlete. Another explanation is that spinal flexibility, spinal muscle strength and highly developed motor pathways protect the players from the potential damage to the spine that might result in pain. Indeed, severe back pain is uncommon in footballers and injury patterns such a spondylolisthesis (as often seen in cricket players) is absent. One noteworthy exception to this is David Beckham who suffers from back pain. He has been reported to have one leg (left) shorter than the other; this, together with his unique kicking style, may put unusual stress on certain areas of his spine and therefore cause his particular pain and dysfunction.
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The spine is a complicated system of segmented levers with 33 joints stacked one on top of each other, separated by small shock absorbers. It is therefore no wonder that it occasionally fails. As people age, so do the intervertebral discs, and this process can start as early as the mid-20s. Players are therefore at increased risk of injury to their spine during the peak of their career but this is likely to be a feature of degeneration and heavy demand rather than one of increased rate of injury because of a single occupational aspect of sport.
Seasonality and overuse injuries Footballers generally only have four to six weeks off from training and playing. If they are not involved in cup games or representing their country, they may stop playing in mid-May and restart pre-season training in July. However, if they are playing for their country in tournaments (such as the World Cup) most players will be lucky if they have three to four weeks of not playing football. With this amount of time spent playing, overuse injuries are not uncommon. Overuse injuries are unlikely to be a significant influence in overall injury trends. The risk of injury is related to the time spent playing (just as the risk of a driver crashing a car is related to the number of miles travelled). Below a certain minimum playing time, the risk is increased where there is a lack of skill or training or there is poor fitness, but above this level, increased play, on balance of probabilities, will result in increased injuries.
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SOCCER ARTICALS Although this makes sense, research has found that top level football players who also represented their country in a World Cup (and so played more games than players who did not play for their country) did not show any increased risk of injury during the season, and actually had a lower injury risk at training than non-World Cup players (14). Pre-season injuries in football are inevitable, possibly due to a number of factors, such as a decrease in fitness, hard playing surfaces (after the summer), fatigue or inappropriate content or progression of pre-season training programmes. One study found that 17% of all injuries occurred during pre-season training, with the average time lost from these injuries being 22 days. It was also found that younger age groups (17-25 years old) sustained more pre-season injuries that senior players (26-35+ years old) (15). Overall, however, injury in youth team (academy) football is approximately half that of professional players (16).
In this modern era, with increased coverage of football on television, media demand and financial influence, we all want to know how and why our favourite football players are getting injured, and when they will be able to play again. For the fans, this is an important question; for the club and player it is a vital question. With the cost to professional clubs in England of injuries occurring during an average season estimated to be in excess of £75m and up to 10% of the professional squad unable to play due to injury, it is imperative that measures to prevent injuries, and not just to treat them, are in place. Studies have shown that better shin pad design may help cut the rate of tibial fractures (sometimes known as ‘footballers fracture’) (17). However, this particular study also showed that 85% of footballers wearing shin pads still sustained a tibial fracture, suggesting there’s a long way to go. Other simple measures may prevent some of these injuries. These include:
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What can we learn?
a joint approach to training between the medical and coaching staff; a progressive training regime during the pre-season; wearing running trainers or shock absorbent orthotics when the ground is hard
in pre-season; using other training methods to get players’ cardiovascular fitness up prior to
running, eg cycling. Injuries also occur at the amateur level. There are essential differences between the amateur and professional footballer (apart from the salaries!) and this revolves around training and pre-game preparation. The lessons that have been learned in professional football should be used in the amateur game in an attempt to reduce injuries. Likewise, the lessons from other sports should be used to help professional footballers improve their game and prevent them from becoming injured.
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References 1) Br J Sports Med 1999; 33:196-203 2) Acta Orthop Scand 1976 Feb; 47(1):118-21 3) Am J Sports Med 2004; 32(1 Suppl):23S-7S 4) Medical News Today, 2nd May 2006 5) The FA.com; 24 June 2003; ‘Close Season Encounters’ 6) BBC Sport; Health & Fitness; ‘Metatarsals – a football fad?’ 7) The FA.com; 17th March 2004; ‘Putting the boot in’ 8) FIFA.com; Feb 2000; ‘Taping Ankles: Prevention or Cure?’ 9) Am J Sports Med 2000; 28:S (2000) 10) Am J Sports Med 1992; 20(6):686-94 11) Am J Sports Med 2006; 34(3):415-22 12) Sports med 2002; 32(7):419-32 13) Br J Sports Med 2001; 35;43-47 14) Br J Sports Med 2004; 38:493-497 15) Br J Sports Med 2003; 36:436-441 16) Br J Sports Med 2004; 38;466-471 17) Br J Sports Med 1996; 30;171-175
Sports Injury: Anterior Cruciate Ligament Facts New findings on ACL injuries in football
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TJ Salih is a chartered physiotherapist and worked for Tottenham Hotspur Football Club for two seasons, before establishing his own clinic, Back2Normal – www.back2normal.co.uk
Rupture of the anterior cruciate ligament (ACL) in the knee is the injury that causes the longest lasting disability to footballers. Now a new study from Denmark has shed unexpected light on the causes of this injury that should help to prevent it in future. The researchers, from a hospital sports clinic, surveyed 113 patients, consecutively admitted to their clinic with an ACL rupture sustained while playing football, to analyse the mechanism behind their injury. Their key findings – some of them surprising – were as follows: Goalies sustained as many ACL injuries as other players; 62 ACL injuries occurred on the opponent’s half of the field – 18 of them inside
the penalty box; There was no statistical difference between the numbers of players in
defensive and offensive roles at the time of injury; 30 of the injured players were in contact neither with other players nor the
ball at the time of injury and 58 were in contact with the ball alone; Only 17 sustained an ACL rupture while being touched or pushed;
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SOCCER ARTICALS 56 had intended to change their direction towards the side of the injured knee
at the time the ACL was torn, while only ten had intended to turn towards the uninjured side; 26 sustained their injury when landing after heading the ball, of whom 20 were being tackled by an opponent in the air, so jeopardising their landing; 19 had a previous injury other than an ACL injury in the now ACL-injured knee, compared with five in the other knee. The researchers draw two main conclusions from their findings:
Secondly, two distinctive actions – change of direction and landing after heading – are responsible for the vast majority of ruptures. If players could be trained to perform these particular moves more safely, the risk of injury could be substantially reduced. Int J Sports Med 2006; 27:75-79
Powerful, Accurate and Injury Free Kicking A Mental Guide Kicking Training for Rugby and Football Training for kicks – just how can you improve kicking performance?
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First, that ‘the mechanism behind ACL rupture differs from that of other soccerrelated injuries because only a small fraction of the injured players had contact with another player at the time of the accident. We therefore conclude that tackling and kicking do not contribute significantly to ACL ruptures in soccer’.
On the face of it, kicking a ball seems the simplest thing in the world. But as John Shepherd explains, powerful, accurate and injury-free kicking doesn’t just happen by accident; it requires the right mental approach combined with appropriate skill development and physical conditioning Have you ever wondered why you seem to have two left feet, or why you’re prone to hamstring strains when it comes to kicking a ball? And where you should look when you are about to put the ball in the net from the penalty spot? Although it’s something we take for granted, the ability to kick is like any other sports skill in that it can be developed and improved. And like other sports skills, improvement requires the correct mental, as well as physical, approach Using the mind to improve kicking Mental training can play a vital role when it comes to improving kicking technique and one of the most important training methods is visualisation, which involves running
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SOCCER ARTICALS through the performance of a sports skill in the mind. For this to be most effective, the skill should be practised at real speed; visualising a skill at slower speeds can be detrimental, as it can ‘pattern’ this skill in the brain at a ‘less than optimal’ velocity – ie the motor system becomes better at executing the action, but only at lower speeds.
Regular visualisation will bolster confidence, physical practice and maximise the potential for successful kicking. To aid visualisation a ‘script’ can also be established. Basically, this is a set of instructions that the athlete runs through repeatedly in their mind as they visualise the kicking action. Here is an example that could be used to support the visualisation used by a football penalty taker: I will place the ball calmly and securely on the spot; I will look at the goalkeeper to assess his position, inhale, and turn around and
walk back nine steps; As I do this, I will breathe out and remind myself of where I am going to place
the ball; I will pause, turn towards the goal, and look at where I am going to place the ball; I will see the ball going into the net where I want it; I will breathe in and slowly out before I start my run; I will start my run; I will strike the ball cleanly with the in-step of my foot, placing the ball to the left of the keeper, low and hard into the corner; I will not lift my head or eyes until the ball is on its way into the back of the net.
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When visualising a kicking skill, you should find a quiet spot, relax and run through it in your mind in varying conditions and states of fatigues. For example, an elite rugby goal kicker could visualise slotting the ball between the posts from a position that is least preferred (eg on the ‘wrong’ side of the posts), in the wind and rain, in front of a TV audience of millions and against particular opposition.
Visual acuity How does David Beckham bend it? The former England captain is one of the world’s greatest deadball specialists. He has a unique kicking action, which has been attributed to his specific lower leg physiology, enabling him to give the ball more spin, curl and dip. His ability to wrap his kicking foot around the ball is enabled by his nonstriking leg seemingly being able to bow almost stick-like, as he strikes the ball. This drives his kicking foot into the ball in a very unique manner. So what do you do without Beckham’s legs? Well, research has indicated that the angle of the approach run when taking a kick will have a significant effect on kicking biomechanics (the greater the angle the greater the ability to impart swerve, dip and
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SOCCER ARTICALS curl)(1). And deciding where to place the ball before striking it is crucial, as is where and how you actually look when you strike the ball. Japanese researchers considered the latter in regard to short and long in-step kicks(2). Players were asked to aim at a target; the top three scorers were defined as the ‘highscore group’ (HSG) and the three low scorers were defined as the ‘low-score group’ (LSG). Analysis indicated that: The HSG was characterised by longer ‘quiet eye’ durations (constant focus
gaze) on the target prior to kicking; The LSG spent less (quiet eye) time focussing of the target prior to kicking; The HSG score group kept their eyes down for longer when they struck the ball,
This research corroborates the accepted wisdom of looking at the ball when kicking, and not where it is going to be kicked when striking it. This is to avoid lifting the head (and in the case of the research above raising the eyes), which alters the biomechanics and accuracy of the subsequent kick. Preferred versus non-preferred kicking foot Most of us have a preferred kicking foot and a team of researchers from Denmark have looked at the possible biomechanical reasons for this(3). Seven skilled soccer players performed maximal speed place kicks with their preferred and non-preferred leg. The kicks were analysed with high-speed video recording equipment. Among numerous variables, the rate of force development in the hip flexors and the knee extensors (quadriceps) was measured using a dynamometer.
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specifically keeping focused on a point between the ball and target.
Not surprisingly, higher ball speeds were achieved with the preferred leg. The researchers attributed this to higher foot speed at the point of ball impact and a consequential ‘better inter-segmental motion pattern’ (ie smoother kicking action). Specifically, in terms of muscle recruitment/action at foot-strike, this was related to the angular velocity of the thigh. Research carried out on kicking in Aussie rules football also vindicates the importance of skill when it comes to kicking optimally with either foot(4). The researchers concluded that, ‘Kicking a football accurately with a certain velocity over a certain distance is dependent on the speed of the kicking foot and the quality of the contact between the foot and the ball – qualities that are primarily skills led.’ Any football player wanting to achieve parity between their kicking legs should therefore emphasise skill and, to coin a well used phrase in coaching, follow the mantra that ‘perfect practise makes for perfect performance’. They should also begin early, during the ‘skill hungry years’, between the ages of 8 and 12, when the body and mind can most rapidly learn the correct motor skills.
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SOCCER ARTICALS Kicking conditioning In most sports, improving strength and power improves performance. So does the same apply to kicking? Greek researchers examined the effects of a football strength and technique conditioning programme on the kinematics (movement of the body/limbs) and electromyographic (EMG) muscle activity during in-step kicking(5). Ten amateur football players made up the experimental group (EG) while 10 other players served as controls.
Kinematics in the form of three-dimensional data; EMG readings from six muscles in the swinging (kicking) and support legs prior
to and after the training programmes; Maximum isometric leg press strength; 10m-sprint performance; Maximum speed on a bicycle ergometer.
The researchers discovered that compared to the controls, the EG improved significantly in relation to maximum ball speed and the linear velocity of the foot and ankle, and the angular velocity of all the joints during the final phase of the kick (it has been previously noted that faster foot speed/limb speed results in longer and more powerful kicking).
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The EG followed a 10-week football-specific training programme. This combined strength and technique exercises. All participants performed an in-step kick using a two-step approach. The researchers recorded:
However, training had insignificant effects on EMG values, apart from an increase in the average EMG of the vastus medialis (thigh muscle that contributes to leg extension, ie kicking). Additionally, maximum isometric strength and sprint times were significantly improved after training. This lead the researchers to conclude that ‘…the application of training programmes using soccer-specific strength exercises would be particularly effective in improving soccer kick performance.’ However, not all the research backs this up. Further research from Denmark considered three different 12-week strength training protocols on 22 elite football players(8). Four groups were established: 1. A high resistance (HR) group who performed 4 sets, 8 reps at 8RM loading; 2. A low resistance (LR) group who performed 4 sets, 24 reps at 24RM loading; 3. A loaded kicking movement group (LK) who performed 4 sets, 16 reps at 16RM loading (loaded kicking drills include those using elastic bungee or power chords, which wrap around the foot and allow the kicking action to be performed against resistance.);
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SOCCER ARTICALS 4. A control group (CO). When peak isokinetic, concentric and eccentric force was measured, the researchers discovered that isokinetic knee joint strength was unchanged in the LR, LK, CO groups. However, the HR strength training players experienced greater eccentric and concentric force generation capability when kicking. However, despite this apparent kicking strength gain, actual kicking performance estimated by maximal ball flight velocity was unaffected – contrasting with the findings of the Greek team.
Thus it appears that experienced footballers can benefit from specific training, but the effects appear to be peripheral to the actual enhancement of kicking power. The heavy weight protocol does seem to offer a pathway to increased power but this may not translate directly into kicking distance due to the specifics of the kicking action and the high skill requirement. It seems therefore that (as with most technical sport skills) enhanced strength must be constantly married to technique if this is to translate into improved performance. Beating kicking-induced hamstring injuries Those involved in kicking sports are more prone to hamstring injury. A British team discovered that the incidence of hamstring injuries for top rugby players was 0.27 per 1,000 player training hours and 5.6 per 1,000 player match hours(9). On average, injuries resulted in 17 days of lost time, with recurrent injuries (23%) significantly more severe (25 days lost) than new injuries (14 days lost).
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This researchers concluded that only the heavy-resistance strength training induced increases in isokinetic muscle strength, and that the actual value of this training was likely to be more about injury prevention – specifically in terms of providing stability to the knee joint during fast extension (kicking) movements.
Second-row forwards sustained the fewest (2.4 injuries/1,000 player hours) and the least severe (7 days lost) match injuries. Running activities accounted for 68% of hamstring muscle injuries; however, injuries resulting from kicking were the most severe (36 days lost). Similar relatively high rates of hamstring strain have been discovered in professional football(10). In the rugby study it was discovered that players who included Nordic hamstring exercises in addition to conventional stretching and strengthening exercises in their conditioning routines, had lower incidences and severities of hamstring injury during training and competition. The Nordic hamstring exercise specifically develops eccentric strength in the hamstrings. This is important as it is during the ‘lengthening under load’ eccentric muscular action phase of numerous speed/power movements, including kicking when hamstring injuries are more likely. Researchers have in fact estimated that 85% of the
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SOCCER ARTICALS energy involved in kicking at and after foot-strike is a consequence of the eccentric action of the hamstrings(11). Conclusions
References 1) Med Sci Sports Exerc 2004; 36(6):1017-23 2) Percept Mot Skills 2006; 102(1):147-156 3) J Sports Sci 2002; 20(4):293-9 4) J Sci Med Sport 2003; 6(3):266-74 5) Scand J Med Sci Sports 2006; 16(2):102-10 6) Scand J Med Sci Sports 2006; 16(5):334-44 7) J Sports Sci 2006; 24(9):951-60 8) Acta Physiol Scand 1996; 156(2):123-9 9) Am J Sports Med 2006; 34(8):1297-306. Epub 2006 Feb 21 10) Br J Sports Med 2004; 38(6):793) 11) Am J Sports Med 1998; (6):185-193 Get o
tournament football
Tournament Football : What Sven can learn from research in the lead-up to the 2006 World Cup
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Specific conditioning methods seem to be slightly peripheral (particularly for experienced players), while high resistance weight training has its advocates and can be useful in terms of injury prevention, as can eccentric hamstring exercises. However, it appears that the biggest factor for improving kicking ability in terms of accuracy and distance are repeated, technically correct practices, with consideration paid to where to ‘look’. Mental training can also be highly beneficial.
‘In tournament football, fitness and conditioning are absolutely vital. They are among the most important things. You also need a little bit of luck with injuries and penalties and things like that.’ So says Sven Goran Eriksson (1). Wise words indeed from the England manager, but can PP make him any the wiser? This article takes an in- depth look at some of the key factors that impinge on creating a winning World Cup team, by John Shepherd. Next year’s playing season is designed to give the England squad more time to prepare for the 2006 World Cup in Germany. But will the rigours of a Premiership and European season for the majority of the English-based players have taken its toll on their readiness for the biggest tournament on earth? Research by Ekstrand and his colleagues from Linkoping University in Sweden looked specifically at the domestic season’s toll on topflight footballers from across Europe in the lead- up to the 2002 World Cup, focusing on the impact of number of matches
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SOCCER ARTICALS played on injury rates (2). Team doctors at 11 of the best football clubs in Europe monitored their players continuously over the 2001/02 season, when 65 of the players participated in the Korea/Japan World Cup. During the tournament the clubs reported the injuries sustained by these players, while three international experts analysed how well they played.
Perhaps surprisingly, given that they played more games, the World Cup players did not experience a greater injury rate than non-World Cup players during the season, However, 29% of them sustained injuries in Korea and Japan. And, ominously, 23 (60%) of the 38 players who had played more than one match in the week before the World Cup incurred injuries and/or underperformed during the tournament. This led the Swedish researchers to conclude that the number of games played in the last 10 weeks before the tournament was particularly crucial in terms of potential injury risk and/or underperformance. What of the demands of international football? Are those who play regularly at this level any more prone to injury than others? And should Sven forgo friendlies in the lead-up to Germany in consequence? This question was the subject of further research by Ekstrand, who carried out a longitudinal study of the Swedish team between 1991 and 1997(3). During this six-year period the team played 73 official matches and attended three training camps. Fifty-seven of these matches and the three training camps were included in the study, amounting to a total of 6,235 training and 1,010 match hours. Exposure to football was recorded individually for each player, and the team doctor examined all injuries.
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Domestic games played by Europe’s elite varied between 40 and 76. Not surprisingly, top players (or at least those in the more successful sides) played more matches, especially during the final period of the season, when there were more cup commitments. In all, World Cup players played 46 matches, compared with 33 for nontournament players.
In all there were 71 injuries (40 incurred during training and 31 during match play). Five (16%) of the match injuries were major and resulted in more than four weeks out of the game. The incidence of injury during training was 6.5 per 1,000 player hours, while the incidence during matches was 30.3/1,000 hours. Interestingly, a significantly higher injury incidence was found in matches lost than those won or drawn (52.5 compared with 22.7/1,000 hours), although no significant difference in injury rates was found between competitive and friendly matches and between matches played on home, away and neutral ground. These findings led Ekstrand to conclude that the risk of injury when playing for a national team was comparable to that previously reported for professional football at a high level. However, given his previous findings (2), it would seem prudent for the
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SOCCER ARTICALS English Football Association (FA) to limit their team to essential games only in the lead-up to the World Cup, to minimise the risk of injury and impaired performance in the tournament itself. England should also be careful to win all its games! The quote from Eriksson in my introductory paragraph mentions the importance of luck, and there is certainly a huge element of luck involved in injury risk, as FIFA, the international governing body of football, discovered when analysing the incidence and type of player injuries that occurred during the 2002 World Cup (5).
So, statistically speaking, luck will play a prominent part in determining Eriksson’s players’ injury risk, as there is not much than can be done to avoid contact injuries, especially if these are instigated deliberately by players on the opposing side. (Note: FIFA will be pushing the importance of ‘fair play’ in Germany in an attempt to reduce the incidence of deliberate fouls).
How to follow in Brazil’s footsteps Luis Filipe Scolari, manager of the victorious Brazil side in the 2002 Football World Cup, summarised the reasons for his team’s victory in the following terms(4):
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The team doctors of all the participating teams reported all injuries after each match on a standardised injury report form, and a total of 171 injuries were reported from the 64 matches, equating to an injury rate of 2.7 per match. Of all the injuries, 73% were contact injuries and the remainder incurred without contact with another player. Half of the contact injuries (37% of total injuries) were caused by foul play as defined by the team physician and the injured player.
The staff and team created a ‘winning spirit’; The staff focused the energies on convincing the younger players that they
could win if they wanted to. The veteran players already believed in their ability; Scolari interviewed all of the players’ individual club coaches, allowing him to gather additional information on his team; The staff constantly gathered statistical data on all of the team’s games and shared the information with the players, focusing on where goals were scored for and against; They put considerable effort into exciting the passions of the players as they felt that volatile Latinos were more likely to be led by their hearts than their minds! Physical fitness tests were carried out for all players at the very beginning of training so that there was a clear baseline from which improvements could be measured; The coaching staff focused on giving the players organisation and discipline as a team; They focused a lot of energy on winning the first game, as this was seen to be vital for mental preparation.
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SOCCER ARTICALS Hamstrings and hydration It is beyond the scope of this article to go into detail about football conditioning and pre-conditioning methods. However, I do want to focus on hamstring protection and player hydration since these are among the most important determinants of player endurance (in all senses of the word) in tournament football. A strained hamstring will almost inevitably mean the end of the line for a player – at least as far as this particular tournament is concerned – while inadequate hydration can significantly impair performance and even increase injury risk.
Although there was considerable variation in the way the different clubs trained for flexibility, the researcher discovered (surprisingly, given its limited relevance to match and training conditions) that static (passive) stretching was the most popular method. In terms of injuries, hamstring strains accounted for 11% of the total and one third of all muscle strains, while about 14% of hamstring strains were re-injuries. HSRs were most prevalent in the Premiership (13.3 for every 1,000 playing hours) and least prevalent in Division 2 (7.8 per 1,000 hours), with forwards mostly likely to be injured. Most (97%) hamstring strains were grade I and II and two thirds of them occurred late during training/matches.
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UK researchers Dadebo and a team from Manchester Metropolitan University investigated the relationship between current flexibility training protocols and hamstring strain rates (HSRs) in English professional football clubs (6). Data on flexibility training was collected from 30 clubs in the four divisions during the 1998/99 season.
Just to explain this terminology, a grade I strain might consist of small micro-tears in the muscle; a grade II strain would be a partial muscle tear and a grade III would be a severe or complete rupture of the muscle. When analysing injury rates in relation to flexibility protocols, the researchers concluded that about 80% of hamstring strain rate variability was accounted for by stretching holding time. In other words, the longer the muscle was stretched, the more likely a player was to suffer a hamstring strain. The implication of this research is that if hamstring strains are to be reduced among elite players, club coaches need to be better educated on the merits of active warmups, including specific stretches (of which more later). Fluid loss can inhibit performance and increase injury risk. We must hope that the England team will not assume that because the games are to be played in European conditions, albeit summer ones, there will be less need to pay attention to player
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SOCCER ARTICALS hydration, as a large body of research suggests that such a lax attitude could lead to the team flying home early. Maughan and colleagues from Loughborough University measured fluid balance during a 90minute pre-season training session in the first team squad of an English Premier League football team (7). Sweat loss during the session was measured by changes in body mass after taking account of fluids ingested in drink and excreted in urine. Sweat composition was analysed by patches attached to the skin at four sites.
Maughan concluded that sweat losses of water and solute (liquid containing electrolytes) in footballers in training can be substantial. However, there was considerable variation in losses between players, even in the same exercise and environmental conditions. There was also considerable variation in voluntary drinking, which was generally insufficient to compensate for fluid losses. So it seems that Sven and his backroom team need to design and implement individual fluid replacement programmes for each player. To help them, Maughan recommends that players should drink enough to limit weight loss to 1-2% of their pre-training session/match weight. Since salt loss can make players more prone to cramping, he also advises that those with a tendency to cramp should consider taking salt supplements.
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On the day of testing, the weather was warm: 24-29°C, with moderate humidity (4664%) – similar conditions to those expected next summer in Germany. Over the course of the training session, the mean body mass loss was 1.10kg, equivalent to 1.37% of pre-training body mass. Mean fluid intake was 971ml and estimated mean sweat loss was 2,033ml, with a total sweat sodium loss of 99mmol, corresponding to a salt (sodium chloride) loss of 5.8g.
The whole issue of how to calculate your personal fluid needs was covered in a recent issue of Peak Performance (PP 212, 2005) and the message of the article, written by Professor Maughan himself, is summarised in the box below.
Calculating personal fluid needs As a rule of thumb, during an endurance event you should drink just enough to be sure you lose no more than about 1-3% of pre-race weight. This can be achieved in the following way: Record your naked body weight immediately before and after a number of
training sessions, along with details of distance/duration, clothing and weather conditions; Add drink taken during the session to the amount of weight lost, ideally working in kilograms and litres, since 1kg of weight is roughly equivalent to 1L of fluid;
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SOCCER ARTICALS After a few weeks you should begin to see some patterns emerging and can
calculate your sweat rate per hour. This may be as little as 200-300ml or as much as 2-3L, depending on your physiology, your speed, clothing and conditions; Once you know what your sweat losses are likely to be in any given set of environmental conditions, you can plan your drinking strategy for any particular event. Ron Maughan, PP 212, 2005
Finally, we need to consider how to warm up for the big games. And here Professor Angel Spassov has some key pointers for the England side. A football conditioning expert from Bulgaria, now based in the US, Spassov has worked with no fewer than six World Cup squads, most recently Portugal during Euro 2002. Although his warm-up is far from revolutionary (from a general sports conditioning perspective) it is nevertheless very thorough and specific (see panel above right) (8).
Spassov’s active warm-up 1. Non-specific warm-up 6-8 minutes of jogging, followed by neck, shoulder, lower back and abdominal
stretches; Use 2-3 different routines with 10-12 repetitions of each; Next target legs (hamstrings, hip flexors, abductors, adductors, quads and calf
muscle) with passive and dynamic stretches. Perform 23 standard routines with 10-12 repetitions; Be sure to increase speed of performance for every set of the dynamic stretches; Next perform varying-intensity sprints in different directions; By the end of this part of the warm-up, players’ pulse rates should have risen to 160-170 beats per minute.
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Warm-ups for big games
2. Specific warm-up Begin with various kicks of the ball with both legs and various technical moves
with the ball, such as dribbling and stopping the ball; These should progress to medium intensity with one other player and then to
high intensity, with more players combining into groups to practise all technical skills at the highest possible intensity and speed. Spassov advocates a passive and active warm- up, the latter incorporating a specific warm-up. For the former he recommends that players loosen their muscles 30-60
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SOCCER ARTICALS minutes before the game by rubbing ankles, knees, all the muscles of the legs, lower back, neck and shoulders with heating ointment – preferably one that is odourless and not too hot on the skin. The warm-up that follows is divided into two parts, as described in the panel. Spassov’s suggested warm-up makes great sense and should control players’ progression to match readiness. With the first part of the warm-up performed alone, players should be able to focus on their own movements and progression rather than being tempted to lash out at the ball before their hamstrings are fully prepared, with potentially dire consequences.
John Shepherd MA is a specialist health, sport and fitness writer and a former international long jumper
References 1. From www.thefa.com 2. Br J Sports Med 2004 Aug; 38(4):493-7 3. Scand J Med Sci Sports 2004 Feb; 14(1):34-8 4. www.ontariosoccerweb.com 5. Am J Sports Med 2004 Jan-Feb; 32(1 Suppl):23S-7S 6. Br J Sports Med 2004 Dec; 38(6):793 7. Int J Sport Nutr Exerc Metab 2004 Jun; 14(3):333-46 8. www.overspeedtraining.com
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Neither I nor PP is being presumptuous in presenting these findings to Sven. Indeed we would be delighted if the Swede and his team already knew it all and only needed to worry about the luck factor out in Germany – and those penalties of course!
stretching football Stretching football: Stretching no help to kicking in football Static stretching, once an absolute pre-requisite of pre-exercise warm-ups, is increasingly under attack these days as study after study fails to demonstrate its efficacy. The latest blow comes from research carried out on Australian Rules footballers, which showed no significant changes in either flexibility or kicking variables following a stretching warmup. When planning their study, the researchers reasoned that, although static stretching might be unhelpful prior to strength and power activities, it has been found to be
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SOCCER ARTICALS effective for increasing range of motion (ROM) at various joints, such as the hip, which might prove useful for kicking in football. ‘Generally,’ they explain, ‘the greater the distance over which the swinging leg can move, the greater the potential to achieve a high foot speed at the instant of impact with the ball. Therefore, if stretching during warm-up can produce a short-term increase in flexibility, it could potentially enhance the ROM achieved in kicking and, in turn, increase foot speed at impact.’ Their study was set up to determine the effect of static stretching during warm-up on hip and knee joint flexibility, ROM at the hip and knee joints and foot speed during kicking for distance.
The control warm-up consisted of submaximal running and seven kicks of the football at 50- 100% of maximum effort, while the experimental warm-up included static stretching of the hip flexors and quadriceps between the submaximal running and kicking. Immediately before and after each warm-up, the players were assessed for hip flexor and quadriceps flexibility by means of a modified Thomas test, using joint angle calculations in a knee-to-chest position. After this test, each subject performed six labbased maximum-effort drop punt kicks with the right foot into a net about 10m away, while being videotaped to determine the range of motion of the kicking leg and foot speed at impact with the ball.
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Sixteen AR footballers performed six maximum effort kicks following two different warm-ups on two different days, 1-3 days apart.
Key results were as follows: There were no significant changes in flexibility as a result of either warm-up; There were no significant differences between the warm-ups for any of the
kicking variables. The findings on flexibility were considered ‘somewhat surprising’, given that static stretching has been reported to produce significant short-term gains in flexibility in the plantar flexors and hamstrings. It is possible, the researchers speculate, that a stretching routine is more effective for those with ‘tight’ muscles; or that a longer stretching period is needed to produce results; or that the Thomas test was not sensitive enough to detect changes resulting from the stretching warm-up.
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SOCCER ARTICALS However, as they point out: ‘the question of interest is whether or not the warm-ups differed in their influence on ROM and final foot speed in kicking. The results indicated no significant differences between the warm-up conditions on any of these variables, suggesting that stretching had no influence on kicking kinematics.’ They explain that foot speed at impact with the ball is a function of complex neuromuscular patterns from many other muscles. And they conclude that even if static stretching does produce short-term changes in flexibility, these ‘may not be reflected in the kinematics of kicking because of the complexity and multi-factorial nature of this skill’.
Recovery training: active recovery (light exercise) is recommended over passive (resting) recovery for the removal of lactate Recovery training decreases fatigue, accelerates physiological regeneration, enhances adaptation and decreases the risk of injury Recovery is increasingly recognised as a significant component of athletic training and performance – particularly for elite performers, who may be expected to engage in very demanding training two or even three times a day. An adequate recovery is known to decrease fatigue, accelerate physiological regeneration, enhance adaptation and (possibly) decrease the risk of injury. So what is the best recovery strategy?
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J Sci Med Sport 2004; 7:1, pp23-31
Research overwhelmingly supports the superiority of active recovery (light exercise) over passive (resting) recovery for the removal of lactate – a by-product of strenuous exercise – from the circulation. However, the relationship of active warm-down with other measures of recovery – including subsequent performance – remains unclear. And meanwhile there are newer kids on the recovery block – such as sports massage and various water therapies. Hot-and-cold (contrast temperature) water immersion, in particular, is currently being used as a recovery strategy by many athletes and coaches, although there has been very little research to substantiate its effectiveness. This is a gap a team of researchers from New Zealand and the UK sought to fill with a comparison of the impact of active recovery (ACT), passive recovery (PAS) and contrast temperature water immersion (CTW) on repeated treadmill running performance, lactate concentration and pH – the latter implicated as a contributor to metabolic fatigue.
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SOCCER ARTICALS The study involved 14 highly active male volunteers, who completed the following testing protocol on three separate occasions: two treadmill runs to exhaustion, at 120% and 90% of peak running speed (PRS), separated by 15 minutes’ rest. On completion of the second run to exhaustion, participants were exposed to one of the three recovery strategies for 15 minutes, as follows: Active recovery (ACT) – running at 40% PRS on the treadmill; Passive recovery (PAS) – standing upright within an 80cm diameter circle; Contrast temperature water immersion (CTW) – alternating between 60 seconds
cold and 120 seconds hot water immersion, starting with cold and ending with hot.
The following findings emerged from comparison of the three recovery strategies: the type of recovery used had no significant effect on performance in the
subsequent test protocol. High intensity treadmill running performance had returned to baseline four hours after the initial exercise bout regardless of the trial condition used; post-exercise blood lactate concentration was lower with Active recovery (ACT) and contrast temperature water immersion (CTW) than with passive recovery (PAS); blood pH was not significantly influenced by recovery mode; participants reported an increased perception of recovery during contrast temperature water immersion (CTW) compared with active recovery (ACT) and passive recovery (PAS).
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Four hours after the start of the test protocol, participants completed an additional two treadmill runs to exhaustion, as before. Heart rate, rating of perceived exertion during recovery, blood lactate and pH were recorded before each test protocol and during and after each recovery strategy.
‘A novel finding of the present study,’ comment the researchers, ‘is that contrast temperature water immersion appears to provide similar effects for removing lactate from the circulation as active recovery.’ What can explain this effect? It is likely, they suggest, that the alternate dilation and constriction of the blood vessels with hot and cold water immersion boosts blood flow to the immersed muscles, thereby improving lactate removal. Why was this beneficial effect on lactate not reflected in improved subsequent performance? Possibly because the time gap between recovery and performance was overlong at four hours. ‘The potential remains,’ argue the researchers, ‘that the type of recovery modality may have influenced performance if the second exercise bout had been performed closer to the first bout… Further research is required to ascertain the influence of contrast temperature water immersion on the time course for recovery of treadmill running performance.’
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SOCCER ARTICALS They conclude that contrast temperature water immersion (CTW) may be a better recovery strategy than active recovery for some athletes because similar physiological changes are achieved, with reduced exertion and increased perceptions of recovery. J Sci Med Sport 2004;7;1: 1-10
strength football Strength training for footballers
‘Within this aerobic context a sprint bout occurs about every 90 seconds, each lasting an average of two to four seconds,’ observe a group of Norwegian researchers. Also during a game ‘professional soccer players perform about 50 turns, comprising sustained forceful contractions to maintain balance and control of the ball against defensive pressure. Hence strength and power share importance with endurance in top level soccer play. Power is, in turn, heavily dependent on maximal strength.’ Given the lack of data on the relationship between maximal strength and power performance, such as sprint and jumping capacities, in elite soccer players, the researchers set out to study this relationship in a team of 17 elite male soccer players from Rosenborg FC, the most successful team in Norway for the last decade. The players, all full-time professionals, training on a daily basis, were tested for the following capacities:
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With elite male footballers covering 8-12k during a typical game, aerobic capacity is clearly a strong determinant of performance. But what of other capacities, such as strength?
Maximal strength in half squats; Sprinting ability (0-30m and 10m shuttle run sprint); Vertical jumping height.
Analysis of the findings showed a strong correlation between maximal strength in half squats and sprint performance and jumping height, with no positional differences observed among the players. Interestingly, despite previous evidence of an ‘interference effect’ with concurrent strength and endurance training, the results in this group of players showed that a high level of maximal strength did not compromise a high VO2max. The researchers conclude that maximal strength in half squats determines sprint performance and jumping height in high level soccer players.
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SOCCER ARTICALS Given the training regimen employed by the players with a high level of strength in this team, the researchers recommend elite players to focus on ‘maximal strength training with emphasis on maximal mobilisation of concentric movements, which may improve their sprinting and jumping performance’. Br J Sports Med 2004;38:285-288
The role of stretching in enhancing flexibility and reducing injury risk remains contentious, with some studies finding no relation between flexibility training and injury and others pointing to a positively harmful effect. Now, however, a carefully conducted survey of flexibility training protocols in English professional football clubs has suggested that stretching helps to prevent hamstring strains – the commonest and most problematic muscle strains associated with competitive sport. Questionnaire-based data on flexibility training methods and hamstring strain rates were collected from 30 football clubs in the four divisions during the 1998/99 season and analysed for evidence of any relationship between the two. Key findings were as follows: Hamstring strains represented 11% of all injuries and one third of all muscle
strains; About 14% of hamstring strains were reinjuries; Hamstring strain rates were highest in the Premiership and lowest in Division 2; The vast majority of hamstring strains were minor or moderate, with two thirds occurring in the late stages of training sessions or matches; Forwards were injured most often; Use of the standard stretching protocol (a warm-up session followed by either a static or PNF stretching technique, holding the static stretch for 15-30 seconds) was the only factor significantly related to hamstring strain rates, suggesting a protective effect.
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hamstring strains Hamstring strains
‘Our findings clearly suggest,’ conclude the researchers, ‘that the current stretching practices of professional footballers are not detrimental, and an improvement in the quality and consistency of use of more appropriate stretching may possibly further reduce [hamstring strain rates]. ‘Stretching is probably involved in a complex, interactive and multifactorial relation with hamstring strain. However, stretching may be beneficial only if the technique employed and the stretch holding times are adequate; the number of repetitions of a stretch may not be important.
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SOCCER ARTICALS ‘The flexibility training protocols currently used by the professional football clubs need to be reviewed to ensure consistency in the use of static stretching/PNF with a stretch holding time of 15-30 seconds.’ Br J Sports Med 2004;38:388-394
football children Why football is good for children
That is the question a group of researchers from the Canary Islands set out to answer with a study following 17 prepubertal football players and 11 matched controls over a three-year period. The football group, mostly recruited from sports clubs, had been playing football for at least a year and at least three times a week, while the activities of the controls, recruited from schools, were limited to those included in the compulsory PE curriculum (two weekly 45-minute sessions). Bone mineral content and density were measured by dual-energy X-ray absorptiometry at the beginning and end of the study, as were body composition and various fitness variables. Key findings after 3.3 years, when all the participants were still under 13, were as follows:
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There is good reason to believe that the more bone mass you accumulate during childhood, the higher your eventual peak bone mass and the lower your chances of suffering osteoporotic fractures in later life. Youngsters practising gymnastics and other highly demanding sports have been shown to accumulate more bone than their less active peers. But could the same be true for less intense recreational sports – such as football?
The football players exhibited greater bone mineral content (BMC) in the legs
and greater bone mineral density (BMD) in all bone-loaded regions at the end of the study. More specifically, they gained twice as much femoral neck and intertrochanteric BMC in the legs than the controls and increased their femoral neck BMD by 10% more and their mean hip BMD by a third more than the control group; Although the footballers’ percentage body fat remained unchanged, it increased by 11 units in the control group; Total lean body mass increased by 6% more in the footballers than in the controls; The footballers attained better results than the controls in a 300m run test and 20m shuttle run test. ‘Our study shows,’ comment the researchers, ‘that just [three hours] of soccer participation a week elicits a marked osteogenic effect on clinically relevant zones. This is why we think soccer may be considered as a low-cost and effective option to improve bone acquisition in growing children.
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SOCCER ARTICALS ‘Soccer participation entails benefits in cardiovascular physical fitness and soft tissue body composition as it counteracts the socio-cultural tendency to accumulate body fat and improves lean mass. ‘But the most important finding is that it has … osteogenic effects … which may facilitate the acquisition of a higher bone mineral peak, which can translate into a reduction in the risk of bone factures throughout life.’ Med Sci Sports Exerc, vol 36, no 10, pp1789-1795
nutrition for football
That may not be the most scientifically precise instruction a person in my position can receive, but it is a familiar refrain in many football clubs and it has the value of letting you know where you stand! Frustrating? Perhaps. But on a broader level, the role of sports nutritionist in professional football is seen as one of manipulating carbohydrate, protein, fat, fibre, fluid and micronutrient intake to maintain health, promote adaptation to training, and ultimately enhance or – in our particular sport – maintain performance over the course of a season. The role of the nutritionist in football has evolved over the last five years. Compared to some practitioners, I am new in the sport (one dietician at a top Premier League club has been employed continuously for 13 years!), but I am sufficiently long-in-thetooth to have detected significant change over this period. At the time of writing, 19 out of 20 Premier League teams employ someone specifically to take care of the nutritional requirements of their players. This role is not always performed by a nutritionist or a dietician: in many teams the responsibility for implementing a nutritional support strategy falls on the shoulders of the sports scientist, conditioning coach, or physiotherapist.
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Nutrition for football: 'Your role is to make sure there are no fat b******s in my team'
Nutrition in football – a brief history Football was, for a long time, classed as an endurance sport due largely to the fact that a football match lasted at least 90 minutes. As a result, the nutritional requirements of football players were extrapolated from early scientific research carried out in relation to other ‘endurance sports’ such as running and cycling. Yes, it is true that the duration of a football match is normally 90 minutes; however, the training loads associated with these sports are vastly different. On closer inspection it becomes clear that daily energy expenditure of professional football players may not be particularly high. Football players are generally inactive when not training and training load will vary, depending on factors such as the stage of the season, or whether tactical or fitness drills predominate in training.
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SOCCER ARTICALS Ron Maughan of Loughbrough University assessed the dietary intakes of two Scottish Premier League teams (he managed to get 51 players to perform seven-day weighed intakes) and found average daily energy intake to be approximately 2,620kcal and 3,050kcal respectively(1). This is the only published data available on football players in this country and notwithstanding a recent finding that Japanese football players under-reported dietary intakes(2), this work does highlight lower energy requirements than were perhaps originally recommended for professional football players.
Table 1. Energy and macronutrient intakes of élite international football players(3) Sample Energy Nationality Carbohydrate (%) Fat (%) Protein (%) Size (kcal) Senior Swedish 15 4,929 47.0 29.2 13.6 Danish 7 3,738 46.3 38.0 15.7 Italian (1) 33 3,066 56.0 28.0 14.0 Italian (2) 20 3,650 55.8 28.3 15.9 Junior Canadian 5 3,619 48.0 39.0 13.0 Puerto Rican 8 3,952 53.2 32.4 14.4 Total 88 3,682 52.9 30.1 14.5
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If football players were to consume 7-10g of carbohydrate per kg body weight each day (a recommendation found in many a textbook) then a quick calculation that included reasonable amounts of protein and fat would generate a daily energy intake closer to 4,200kcal. In Scandinavia this may be closer to the truth (Table 1). Once the playing season gets underway the Scandinavian subjects typically train seven times per week compared with roughly four sessions in this country. So it is not surprising that energy intakes will exceed 4,000kcal in a country like Sweden.
Not only were early dietary recommendations for professional football players slightly misjudged; a number of other problems existed in the delivery of nutritional support. Football was flooded with science and its analytical techniques, and experts employed by clubs exploited the ‘measure everything’ approach. Blood, saliva, urine, lactate and expired air were all being indiscriminately extracted from players, often with very little feedback offered in return. In the world of nutrition and football, science was calling the shots.
A new climate prevails ‘An athlete’s diet must be high in carbohydrate, moderate in protein, low in fat, include sufficient vitamins and minerals, and plenty of fluid.’ This was the original model with which many football nutritionists used to work. Although very simple, much of it still holds true today. However, as our understanding of the game in this
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SOCCER ARTICALS country has improved, nutritionists have been able to tease out strategies from each of the model’s sub-sections that more closely match the requirements of our sport. What is different is that science no longer holds all the cards. Football has caught up with science and is now dictating where our efforts are directed.
Good attitudes to reducing fat intake are now commonplace in the modern player. Emphasis is placed on increasing intake of certain fatty acids that are found to be lacking in players’ diets. When performing dietary analyses of players, low intakes of essential fatty acids (eicosapentaenoic acid, EPA; docosahexenoic acid, DHA) are consistently reported. Despite the appearance of oily fish in the canteens of football clubs, there may be a case for blanket supplementation in this particular group of sportsmen. There is growing evidence that protein supplementation after training can promote protein synthesis and adaptation of muscle. The type, timing and amount of protein can be manipulated to enhance the adaptive response. The work of researchers such as Bob Wolfe and Kevin Tipton in Texas, and Mike Rennie in Dundee (whose primary interest has been likened to ‘preventing older people falling down’) has enabled us to design strategies of protein-intake that may promote better adaptation to training.
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For, example, the glycaemic index of foods, a ranking of foods based on their immediate effect on blood glucose, has become a particularly useful tool in football. Five years ago the approach in football was to advocate a high carbohydrate, low fat diet at all times. Any food that at all met these requirements would be recommended to players in a bid to maximise muscle glycogen storage for training and competition. Now a more measured approach is employed with the glycaemic index and, to a lesser extent, the insulin index utilised in a bid to control body composition as well as carbohydrate provision. Emphasis is now placed more on achieving optimum carbohydrate intake prior to matches, and during the recovery period after matches, particularly when some clubs find themselves involved in up to three games per week in the busiest part of the season.
Interest in micronutrients has historically been associated with the free radical muscle damage hypothesis. In fact there is now some suspicion that the release of free radical species associated with exercise is necessary for adaptation of the cell to subsequent stressful events. It is entirely feasible, although not proven, that free radicals play an important part in the adaptation of the muscle to hard exercise, and that increased consumption of some antioxidant nutrients might interfere with these necessary adaptive responses. Practitioners now warn against the use of mega-dose antioxidants.
Urine indices to the fore Many indices have been investigated to establish their potential as markers of hydration status. Body mass changes, blood indices, urine indices and bioelectrical impedance analysis have been the most widely investigated. Current evidence tends to favour urine indices, and in particular urine osmolality, as the most promising marker
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available. Five years ago urine colour charts were commonplace on the walls of clubs’ changing room toilets. Nowadays osmometers can be found at Premier League clubs. Urine samples provided by players can be analysed in approximately 30 seconds and the machines quickly identify dehydrated subjects.A recent preliminary report has suggested that American football players who repeatedly suffer muscle cramping in training and competition have greater sweat losses and a higher sweat sodium content than players matched for fitness and other factors but who do not suffer from muscle cramps(4). Data on sweat electrolyte losses in football players in training are now being collected in a bid to identify those players at risk of potentially debilitating muscle cramp.Assessment of body composition plays an important role in nutritional evaluation, particularly in a sport obsessed with body image. Along with body mass, an estimation of body fat percentage (or sum of skinfolds) has traditionally been the requisite regular test demanded by football managers. In addition to the usual body composition assessment methods, a number of other techniques are being utilised in the modern game. The evaluation of skeletal muscle mass, in particular appendicular skeletal muscle, mass can contribute important information to the assessment of nutritional status because it reflects the body protein mass. A major impediment to determining muscle mass is the lack of suitable, easy and non-invasive methods for estimating muscle mass. Lee and others(5) have developed anthropometric prediction models validated against the ‘gold standard’ method of magnetic resonance imagery to estimate total body skeletal mass using skinfold thickness and limb circumferences. These have proved useful in tracking changes in muscle mass associated with inactivity or resistance training protocols.Although expensive, dual-energy X-ray absorptiometry (DEXA) is proving a valuable tool for body composition assessment, particularly with injured players recovering from a period of inactivity. If you are lucky enough to have access to DEXA at a university or hospital, this technology is able to identify accurately fat and lean tissue and can be used both for whole-body measurements of body composition and for providing estimates of the composition of specific sub-regions (eg trunk or legs). The DEXA instruments differentiate body weight into the components of lean soft tissue, fat soft tissue and bone based on the differential attenuation by tissues of two levels of X-rays.Indirect calorimetry is used to estimate daily energy expenditure of individual players, particularly those who are undergoing a period of inactivity through injury. Measuring the oxygen consumption of an individual and time spent during different activities allows a picture of energy expenditure to be drawn. This information can then be used to prescribe eating and drinking plans that match more precisely players’ energy requirements.These are just a few examples of where science and football have worked together to develop player- and sport-specific nutritional support programmes. Science should be committed to meeting the demands of football and not vice versa. It may sound obvious, but it wasn’t always so.
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The challenge ahead Despite the progress that has been made in our understanding of the demands of football, there is a need for continued improvement. No other sub-discipline of sports medicine comes with so many contrasting views of what is right and wrong. The ‘Zone’ diet, the ‘Atkins’ diet, mass supplementation, the concept of the ‘nutritional guru’ – all are still prevalent in the modern game. Players are becoming more demanding due
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Back to the fish and chips? Of course providing a cutting-edge nutritional support programme has no value unless appropriate education (one that is both stimulating and imaginative) is implemented. In a world dominated by R’n’B, fast cars and Louis Vuitton washbags, it is important to pitch your educational material appropriately. ‘Healthy eating’ on its own just does not wash with Premier League football players. Science and technology, pitched correctly, most definitely do. For all the advances science has made, the most important lessons that nutritionists have had to learn are ‘respect the sport’ and ‘know your place’. It is sobering to note that Real Madrid, arguably the world’s best football team, employ no fewer than nine masseurs but do not employ anyone to take care of the players’ nutritional requirements.Finally, my personal working title for this article was ‘The role of fish and chips in modern football’. Five years ago I walked into a football club and one of the first changes I made was to remove the fish and chips from the post-match menu. This wasn’t a popular move and it would be dishonest to say that anything that has been offered to the players since has received anything like the same enthusiasm. Should I go back to fish and chips?Well, potato is a high glycaemic index carbohydrate food thought to be preferable for the recovery of muscle glycogen stores, and fish is a complete protein source possessing essential amino acids ideal for stimulation of muscle protein synthesis. Most importantly, most of players will definitely eat this dish. OK, the high fat content will probably interfere with the glycaemic response of the potato, and, of course, there are other health promotion implications to wrestle with.In actual fact, I probably won’t return to postmatch fish and chips for the players,however popular this would be, but this real-life example does highlight the fact that for all the rewards that science and nutrition has to offer, these can only be achieved if we respect the traditions of the sport and take the players along with us.
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to conversations with other players from other teams, and also other athletes from other sports. Players from overseas bring with them their own ideas (nearly always related to vitamin intake), but very often lacking in scientific support. In addition, at present there is a fundamental mismatch in what players and practitioners view as important. Players believe in supplements, extra vitamins and minerals: anything that involves increasing muscle mass, and reducing energy intake to achieve ‘lean’ body composition. Scientific research, on the other hand, demonstrates that players should concentrate more on appropriate energy intake, and high carbohydrate and fluid intake.Football is steeped in tradition, which many people wrongly write off as Luddite-type conservatism, or little better than old wives’ tales passed around the old boys’ network. It is true that many coaches and support staff are employed from within but it is also true that these people know the sport and its peculiarities better than anyone. Furthermore, the practice of employment from within will eventually spawn a new breed of coaches that have had, one hopes, more positive and enlightened experiences of sports nutrition. There is already evidence of this taking place.
Nick Broad
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SOCCER ARTICALS References 1. Br J Sports Med, 31:45-47. 2. J Sports Sci, 20:391-7 3. Int J Sport Nutr, 8:230-240. 4. Med Sci Sports and Exerc, 35:S48 5. Am J Clin Nutr, 72:796-803.
It has always seemed strange that football – in financial terms, the most professional of sports – is also the least professional in terms of the approach of individual players to training and other aspects of preparation. Football clubs, as employers and investors in the players, have also been slow to take advantage of the opportunities to maximise the return on their expenditure. Nutrition has generally been low on the priority list, if it has featured at all. Every club expects the players to train, but it hardly seems worthwhile insisting on this if the opportunities offered by good nutrition are neglected. One of the key areas where nutrition can have a direct impact on performance is in the area of hydration. There is good evidence that players who become dehydrated are more susceptible to the negative effects of fatigue, including loss of performance and increased risk of injury. There is also growing evidence that excessive sweat losses, especially high salt losses, can be a factor in some of the muscle cramps that affect players in training and competition.
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hydration in football Hydration football - It used to be oranges in the centre circle... now it's a personal hydration strategy
Recently, however, a number of clubs have recognised that hydration is important and that no single strategy suits all players in all environments. This has led to an assessment of individual needs so that a personal drinking strategy can be put in place. This practice appears to have gained ground in American football, where preseason training typically takes place in extreme heat and involves two sessions per day. In recent years, a number of high-profile fatalities, including that of Korey Stringer in the NFL, have raised the awareness of what can happen when things go seriously wrong. Several of the top English football clubs now have monitoring strategies in place.
Zero-cost analysis At its simplest level, weighing of players before and after training gives an indication of their level of dehydration and risk of heat illness. This takes account of both the amount of sweat lost and the amount of fluid drunk and gives the net balance. There will be a small amount of weight loss due to the fuels used to produce energy (mostly carbohydrate, with a bit of fat), but this amount is relatively small. There will also be
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SOCCER ARTICALS water loss from the lungs and loss through the skin. Broadly speaking, a weight loss of 1kg represents a net loss of 1L of body fluid.
All of this is easy to do, and all it requires is a set of kitchen scales to weigh the drinks bottles, a reliable set of scales to weigh the players, and a bit of organisation. The cost is effectively nil – just a bit of time and effort on the part of one of the backroom staff. There is one more measure that can be usefully added, but this needs rather more specialised apparatus and is thus likely to be the preserve of the top clubs only: the measurement of salt losses in sweat.
Identifying salty sweaters There are many ways to measure salt losses in sweat. The one that is most convenient in practice is to use gauze swabs covered with an adhesive plastic film: typically, four are applied at different sites before exercise begins and left in place for an hour or so. After they are removed, the amount of sweat and the amount of salt in the patch can be measured, allowing the ‘salty sweaters’ to be identified. We have made these measurements on the first team squads at a number of Europe’s top teams, typically testing about 20-30 players at each club. They results have been consistent between clubs when the training sessions have been similar, but the variability between individual players has been striking. Key findings in a typical 90minute training session are as follows:
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A slightly better measure is obtained if the player is weighed before and after training or competition (nude and dry on both occasions) and his (or her) drinks bottle is also weighed before and after, assuming that all players drink from their own bottles and that anything that is taken from the bottle is swallowed and not spilled/poured over the head/spat out. If the decrease in weight of the drinks bottle is added to the decrease in weight of the player, we get the actual sweat loss. We also get a measure of the player’s drinking behaviour.
1. Average sweat loss is typically about 2L, but this can vary from about 1L to over 3L, even though all the players are doing the same training in the same conditions and are wearing the same amount of clothing. 2. Average fluid intake is typically about 800-1,000ml, but this can vary from about 250ml to over 2L. 3. There is no relationship between the amount of sweat a player loses and the amount he drinks. 4. The sweat salt content varies greatly: the better acclimatised players have lower sweat content, but again there is a large individual difference. Sweat salt (sodium chloride) losses can reach almost 10g in a single training session in some players, and this during twice-a-day training. Others lose only small amounts – 2g or less in the same training session.
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SOCCER ARTICALS 5. When training takes place in the cold, sweat losses may be almost as high as when training in the heat, but players drink far less and so end up just as dehydrated – or even more so. These findings may appear simplistic and predictable – apart from the last one, which is not intuitively obvious – but they give the training staff of a club which is serious about maximising its human assets a chance to prescribe fluid according to the player’s needs. The aim should be not to drink too much, as some players do, but to drink enough to limit weight loss to no more than 1-2% of the pre-exercise weight.
These simple steps can make a difference between being able to score that vital goal in the last minute and being a virtual spectator. It is only surprising that it has taken the world of professional football so long to realise this. Ron Maughan
football managers Football managers - Who is there to support the managers? A psychologist reflects on survival techniques in a cut-throat world You only have to read the sports pages or listen to the news to learn of yet another football manager who has got the sack, might get the sack or is in trouble. The world of the professional football manager is one in which danger and uncertainty about the future hover over every match the team plays. It is often a lonely and isolated position, which can leave managers vulnerable to psychological stress.
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There is also a suspicion – and I should stress it is no more than a suspicion at present – that players with a very high sweat salt content are more prone to cramp and that this risk can be reduced by salt supplements.
Here, I review the season I spent working with a professional football manager in my capacity as a sports psychologist. While the manager’s name must remain confidential, I want to make it clear that I have his full permission to write what follows. The journey I embarked upon taught me many important lessons about the culture of football and its impact on the psychological wellbeing of managers. I also learned how a sports psychologist could support a football manager in what is often hostile territory. Initially, I focused on developing an understanding of the manager’s work environment. I needed to know what demands were being placed upon him and what their impact was. I discovered that football managers are subject to four main sources of pressure that influence their psychological wellbeing: the players;
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SOCCER ARTICALS the club owners; the fans; the media.
Each of these sources of pressure places different – often conflicting – demands on the manager, all which have to be satisfied. This creates an intensely pressurised working environment.
lack of personal security; isolation; fear of public humiliation; lack of control over his own destiny (ie the players ultimately decide his fate); need to appear strong and in control; need for quick fixes; culture of non-sharing; ego-oriented culture in which everyone is an expert.
These factors need to be fully understood by a sports psychologist if he/she is to work effectively with a football manager. The culture within football expects the manager to be strong and in control at all times, with no place for uncertainty or need for reassurance. Taken in isolation, the above-mentioned factors would be a challenge for anyone, but in combination their effect can be devastating and it is not surprising that managers are prone to stress-related illness.
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The overall effect is to create a climate of uncertainty and insecurity for the manager. The elements of this climate that impact most significantly on his psychological wellbeing are as follows:
What became apparent to me during the season was the lack of support available for the manager, who was often working in isolation to solve difficult problems. In theory, the assistant coach and the management were available to work with the manager, but in reality the manager was responsible for every decision. The fact that he then had to justify those decisions to everyone else was an additional source of stress.
A pendulum mindset? Exploration of the manager’s mindset revealed pendulum-like swings from very negative to very positive which were completely dependent on the outcomes of matches. The following quotes illustrate some of the widely-held beliefs within football that were wholeheartedly embraced by the manager I was working with:
‘When you don’t win people don’t believe in you’; ‘When you are winning you are never wrong’; ‘Players will lose you your job’; ‘You live and die by your decisions’;
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SOCCER ARTICALS ‘I am too soft’; ‘Results make you God’.
While it has been widely accepted that low self-confidence impacts negatively on an athlete’s performance, its effects on the performance of managers have been generally ignored. Furthermore, the consequences are particularly grave for managers: if the team’s results are poor the owners will still own the club, the players will still play for it and the fans will still support it, but the manager will be sacked in an effort to improve the team’s performance. This knife-edge existence leaves managers very vulnerable.
Off-pitch dynamics As my season progressed, it became clear that the toughest issues the manager had to contend with occurred away from the pitch. Examples included players trying to adjust to life in a foreign country, players facing retirement, players involved in gross misconduct, marital difficulties and older players intimidating younger ones. While these issues might appear to have nothing directly to do with the players’ ability to play the game, it became clear that the manager’s ability to help his players resolve them did have a direct impact on performance. And it is in these situations that football expertise, knowledge and ability can’t help you even though they might be the reasons why you were given the job.
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This mindset indicates a lack of stability and balance. When the team is winning, the sense that the manager can do no wrong creates a false sense of security and a ‘feel good’ factor created that is often short-lived. As soon as the team is losing – or even drawing – his whole coaching methodology is called into question, even though nothing has changed fundamentally from one game to the next. The net effect of this is to leave the manager doubting himself and his approach to many aspects of the game. It is extremely difficult to persist with strategies that you believe to be correct when everyone around you is telling you, either overtly or covertly, that you are not doing a good job. And this growing self-doubt soon impacts on the manager’s relationships with players, with other staff and with the club owners.
It was also clear that these situations impacted in different ways for the team and the manager. Your perception of any situation will vary considerably, depending on your role within an organisation. The diagram (right) illustrates a situation in which there were differing beliefs within the team regarding a decision made by the manager. The consequence of this was a shift in the team dynamics, causing rifts and a negative impact on performance. For the coach, the situation generated inner conflict and uncertainty, which led to a lack of self-belief. The result of this was a change in coach behaviour to a more autocratic style.
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First, the confidentiality of the manager had to be assured. The importance of
this principle should not be underestimated, given the culture of football. If other people had known about the work it could have been compromised, as could the manager’s position; Secondly, it was important that I was not a stakeholder in the club and was there solely for the manager’s benefit; Finally, it was important that I was non-judgmental about – indeed unconcerned with – the results. Our agenda was focused on the manager’s response to any given situation, whether on or off the pitch. These principles were vital to the work we undertook. In his world of constant insecurity and mistrust, if he had ever doubted me, the work would have been over. This trust was hard won, but once established it enabled real progress to be made.
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My role as a sports psychologist was to work with the manager to help him find solutions. However, in order for my work to be effective there were a number of fundamental principles that defined the working relationship:
What I learned from my experience was that it is vital to really understand the culture of the game, so that, in a very real sense, you can learn to speak the same language as those who inhabit the football world. Coming from an essentially non-football background, I had to work hard to appreciate the context within which the manager’s job was being undertaken. Sometimes I got it wrong, but through questioning and acknowledging my own limitations I developed my understanding. Ultimately this made me more effective in my role. I discovered that it was good to challenge current practice, but that we had to work through realistic alternatives that would work in football. My role was to support the manager, not solve player problems. My work with the manager had three key aims: To develop more effective inter-personal communication skills; To enhance understanding of group dynamics, and how to affect them; Personal stress reduction.
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SOCCER ARTICALS As the season progressed, the manager was able to use our sessions to tackle difficult situations he was facing. He was able to discuss openly and freely any concerns or doubts that he was experiencing in relation to the players, the owners or even the fans. Consequently, he was being supported, and given the opportunity to develop strategies to help him manage more effectively. In summary it is clear to me is that the managers of the future need to develop skills in inter-personal communication and to have an understanding of group dynamics and effective group management. They also need to work to develop personal coping and stress-reduction mechanisms if they are to survive the cut-throat world of football management. Misia Gervis
Football referees - Dehydration problems for the men in black Given the enormous importance of football referees – reflected in the almost universal tendency for die-hard fans to displace frustrations with the team onto their hapless shoulders – it is surprising that sports scientists have paid so little attention to their physical and psychological status and performance. Now a pair of Brazilian researchers have attempted to redress the balance somewhat with a study of hydration status in six male refs and six assistants (linesmen) during matches of the 2000 Paraná football championship, held in Brazil in their autumn months of March, April and May.
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football referees
Why study hydration status, you might ask? The answer is that negative effects on performance have been shown with modest degrees of dehydration (2% of body weight). And it is generally accepted that cognitive performance is also impaired when dehydration and hyperthermia are present, which could be particularly relevant to the decision-making aspects of refereeing. The subjects were weighed without clothes and had blood samples taken before and after each match, after emptying their bladders. The difference in readings before and after a match, plus ad lib water intake at half-time and urinary volume, were used to estimate total body water loss during the match, with the assumption that a body mass loss of 1kg was equivalent to loss of 1 litre of fluid. The blood tests were analysed for changes in plasma volume – the fluid portion of the blood. The key results were as follows: Referees lost 1.22kg of body weight during matches, equivalent to 1.55% of
their pre-match weight. Total body water loss averaged 1.60L, equivalent to
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SOCCER ARTICALS 2.05% of their pre-match body weight. The difference between the two measurements reflects their half-time fluid intake; Linesmen, by contrast, lost only 0.48kg (0.63%) of their body weight and body water loss averaged 0.79L, equivalent to 1.05% of their pre-match body weight; The referees showed a reduction in their plasma volume, while the linesmen showed no significant changes in haematological status.
‘The physical activity performed by referees is a combination of various types of exercise (walking, jogging, sprinting and reverse running) covering an average distance of 9.3 miles in a match,’ they point out. ‘Our results show that this amount of activity caused significant dehydration which was not redressed by the spontaneous intake of water during the interval. ‘Additional studies are required to find the best form of fluid replacement for football referees (during, before and after a match) to prevent a decrease in their physical and mental performance.’ Br J Sports Med 2003;37:502-506
soccer fitness training Soccer fitness training: Endurance training boosts performance in the field
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The researchers conclude that referees are moderately dehydrated after a football match, whereas their assistants exhibit only a mild, non-significant degree of dehydration.
Soccer players need a combination of technical, tactical and physical skills in order to succeed. It is odd, therefore, that Soccer research has tended to focus on technique and tactics, with little emphasis on how to develop the endurance and speed needed to become a better player. In one of the few studies which has explored the link between endurance capacity and Soccer performance, Hungarian researchers showed that the ranking among the four best teams in the Hungarian top division was reflected by their players' average maximal oxygen-uptake (VO2max) values(1). Another investigation found a significant correlation between VO2max and the distance covered by players during matches, the number of sprints per match and the frequency of participation in 'decisive situations'(2). Some studies have also shown that Soccerers tend to cover less distance and work at lower intensities during the second half of games than during the first half. The logical interpretation of these findings is that fatigue is limiting the players and that if they were fitter they would perform more effectively in the latter stages of their matches. None the less, until now no investigation has clearly shown that improving aerobic
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SOCCER ARTICALS capacity and overall fitness boosts performance on the Soccer field.
Aerobic interval training v extra technical training Players within each team were randomly assigned to either a training group or a control group, so that each team had members in both groups. In addition to their regular Soccer training and play (four 90-minute practices and one game per week), members of the training group performed aerobic interval training twice a week for eight weeks. Each interval workout consisted of four discrete four-minute work intervals at 90-95% of maximal heart rate, with three-minute recoveries at 50-60% of max heart rate. Technical and tactical skills, strength and sprint training were emphasised in most practice sessions, and about one hour of each practice was devoted to mock Soccer games. While the training group members carried out their four-minute intervals, control soccer players engaged in extra technical training, including heading drills, free kicks and drills related to receiving the ball and changing direction. At the beginning and end of the eight-week study period, all players were tested for VO2max, lactate threshold, vertical jumping height, 40m sprint ability, maximal kicking velocity and the technical ability to kick a Soccer through defined targets. After eight weeks of twice-weekly interval training, the players in the training group had improved VO2max by almost 11%, from 58.1 to 64.3 ml.kg-1.min-1; meanwhile control group players had not upgraded VO2max at all! Similarly, lactate-threshold running speed improved by 21% and running economy by 6.7% in the training group, while controls again failed to improve at all. Clearly the players in the training group were gaining tremendous physiological benefits from just two aerobic workouts per week!
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Fortunately, that deficiency has now been remedied, thanks to the work of Jan Helgerud and his colleagues at the Norwegian University of Science and Technology in Trondheim(3). Their new study involved 19 male players from two Norwegian junior lite teams - 'Nardo' and 'Strindheim' - all of whom had been playing Soccer for at least eight years. Both teams had been among the most successful in Norway over the past five years and six of the participants were members of the Norwegian national junior team. The players had an average age of 18 and mean mass of 72kg (158lb).
Happily, all of these physiological details translated into some markedly improved performances on the Soccer field: interval-trained athletes increased the total distance covered during games by 20% (from 8,619 to 10,335m) and also doubled the number of times they sprinted during games (a sprint being defined as an all-out run lasting at least two seconds). Furthermore, after eight weeks of interval training the number of involvements with the ball per game increased by 24%, from 47 to 59. (Involvements were defined as situations in which a player was either in physical contact with the ball or applying direct pressure to an opponent in possession of the ball.) Interval training also boosted the athletes' overall ability to play at high intensity; after eight weeks of interval work, they were able to perform at an average of 85.6% of max heart rate during their games, compared with just 82.7% beforehand. Training
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SOCCER ARTICALS group members also spent 19 minutes longer than controls in the high-intensity zone (ie above 90% of max heart rate) during an actual game. Of course, interval training isn't a panacea, and sprint speed, squatting strength, bench-press strength, jumping height, kicking velocity and the technical shooting and passing test were unchanged by the aerobic work, as you might expect.
No Soccerer can argue that he/she does not have enough time for such additional training, which should be included in all overall programmes. Interestingly enough, the VO2max ultimately attained by the interval-trained players (64.3 ml.kg-1.min-1) is above the average VO2max reported for experienced international Soccerers, suggesting that a large number of Soccer players could benefit from aerobic training. Athletes in many other disciplines which are not traditionally viewed as endurance sports might also benefit from the kind of interval training carried out by the Norwegian Soccer players. In particular, interval work should offer advantages for those involved in rugby and basketball. Recent research carried out at the Victoria University of Technology in Australia revealed that basketball places huge demands on the cardiovascular system, suggesting that aerobic capacity improvements might upgrade the quality of play(4). In this study, eight players (three guards and five forwards or centres) from the Australian National Basketball League were monitored during league competition and practice games. Each competition consisted of four 12-minute quarters, with a 15minute break at half time and two-minute breaks between quarters. Maximal aerobic capacity (VO2max) was determined for each player.
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None the less, this very simple interval training programme (with just two workouts per week and four 4-minute intervals @ 90-95% of max heart-rate per workout) produced some dramatic improvements in overall play. Put simply, boosting VO2max, lactate threshold and running economy with interval routines gave the players an enhanced ability to cover longer running distances at higher intensities during games and to be involved with the ball more frequently and thus play a greater role in deciding the outcomes of competitions.
When the ball was in play, there was a change in movement category (for example, from medium-intensity shuffling to sprinting) every two seconds, and 'very intense' activity accounted for almost 30% of court time. This translated into a heavy load on the players' cardiovascular systems, with heart rate during play averaging 89% (compared with 86% of max for the interval-trained Norwegian Soccer players and 83% for the Norwegian controls). Basketball players' heart rates were above 85% of max for at least 75% of court time. Even more impressively, cardiac beating was in the 95-100% of max range for 15% of court time and in the 90-95% range for 35% of total time. During free-throw shooting, heart rates recovered to around 70-75% of max. Interestingly, blood-lactate levels were also quite high in the basketball players, with average lactate concentration at 6.8 millimolars (mM)/litre. Somewhat surprisingly, lactate levels as high as 13 mM/litre were recorded in some of the athletes, comparable to those seen in top-level sprinters after 400m races. These findings
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SOCCER ARTICALS suggest that lactate-threshold improvement might benefit basketball players' performances. Overall, there were about 105 'high-intensity' efforts per player per basketball game, and each such exertion (whether it involved fast running or intense side-to-side shuffling) lasted for about 14 seconds. Thus, a basketball game was a bit like carrying out an interval workout with 105 14-second reps. Recoveries between repetitions were short, since intense efforts occurred every 21 seconds.
What other interval workouts besides the Norwegians' 4x4-minute scheme might be beneficial for Soccer and basketball enthusiasts? Clearly, some of the renowned French scientist Veronique Billat's 'v VO2max' sessions would be helpful, since they are very intense in nature and lead to enhancements in VO2max, lactate threshold, and running economy. Two of Veronique's workouts should be particularly beneficial: l The 30-30. To perform this workout, athletes should simply warm up effectively, then alternate 30 seconds of running at close to max intensity with 30 seconds of easy ambling. Initially, they should go for 10 reps, but as aerobic capacity improves they can simply keep going until fatigue kicks in; l The 3-3. This is like 30-30, except that athletes alternate three minutes of hard running with three minutes of loping. The pace for the strenuous three-minute intervals should be determined by the best-possible speed achieved during a sixminute test. (Naturally, 're-tests' of six-minute velocity will be needed every 4-6 weeks-or-so, since running capacity should improve.) Few athletes should try to complete more than five three-minute intervals per workout.
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As it turned out, the Australian basketball players had average VO2max readings of 61 ml.kg-1.min-1, compared with 64.3 in the interval-trained Soccer players and 59.5 in the control group. This suggests not only that basketball itself boosts VO2max but also that improvements in VO2max might foster better play, just as it does in Soccer.
What's the bottom line? In several key ways, Soccer and basketball count as 'endurance sports', since they place a high demand on the cardiovascular system, and since performance ability appears to hinge on physiological variables such as VO2max, lactate threshold and running economy. Thus, performing the types of interval workouts used by endurance athletes should be helpful to players of both sports. Owen Anderson References Science and Soccer, T Reilly, A Lees, K Davids, and WJ Murphy (Eds). London: E & F N Spon, 1988, pp 95-107 2. Proceedings of the 1st International Congress on Sports Medicine Applied to Soccer, Rome, 1980, L Vecchiet (Ed) Rome: D Guanillo, 1980, pp 795-801
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training for football and rugby Football and rugby teams pre-season training
As far as football was concerned, the range of debate was wide, including such areas as psychological and physical preparation of players, coaching, biomechanics, sports medicine, match analysis and sociological perspectives. It was very much a multidisciplinary conference, so it's a pity there was so little representation from British football clubs, who might have learned something. This could be one reason why British football is starting to lag behind the rest of the world. Other nations appear far more ready to take on new ideas for the preparation of their players. At this time of year, most clubs are concerned with the conditioning of players in the pre-season build-up. In this period players can concentrate on the development of skills and fitness without the stress of impending competition week in and week out. A couple of papers at the congress addressed the subject of pre- season conditioning, as there is little published work on what is the best blend of training to get to the season in good shape, as well as what fitness improvements can realistically be expected in this training period. Probing the Welsh national rugby squad A study from the Cardiff Institute of Higher Education aimed to examine these fitness changes through the pre-season period in elite rugby players. The players studied were from the Welsh national squad, consisting of 18 backs and 21 forwards. A battery of fitness tests was administered in both June and September of the same year to examine the change in fitness profiles. The results from the first round of tests were used to assist prescription of the players' training schedules by looking at their strengths and weaknesses.
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The Third World Congress of Science and Football took place in Cardiff earlier this year. The congress included not only keynote lectures from authorities throughout the world but also short communications and poster presentations on scientific aspects of sport relating to all codes of football. But football wasn't the only sport on the menu-rugby, Aussie Rules, Grid Iron, Gaelic and the fast-growing sport of touch rugby for women Down Under were all discussed as well.
It was surprising to see that in this conditioning period there was only a small improvement in the aerobic endurance of the backs, and little change in that of the forward players. The fitness levels were typical of those expected in good-standard rugby players. There was, however, improvement in flexibility and the strength performance of the players, while there was a decrease in explosive leg power, a vital aspect of performance in the game. It would appear from the data presented that forwards may need to put more effort into improving aerobic endurance than they currently do. Although rugby is characterised by short, intense bursts of activity, there is little doubt that better aerobic endurance would help the players to maintain a higher work output throughout the duration of a match. It is also important to improve explosive power during this conditioning period. ...and an English first-division football team A similar project, carried out by Staffordshire University, examined the effect of a
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Once again, a battery of fitness tests was used to assess the players both before and after the conditioning period. Over this period there was a significant improvement in aerobic endurance, as shown by a large increase in performing a progressive shuttle run to exhaustion. This improvement in endurance performance, a function of the hard aerobic training undertaken, was also reflected by a significant decrease in body fat percentage. Although performance of an agility run test also improved during the conditioning period, there was no improvement in the other fitness parameters measured, such as anaerobic endurance, flexibility, strength and power. Once again, these are important parts of match fitness which appear to have been relatively neglected in the training programme and may need attention in future. Losing leg strength Both these papers highlight the danger of inhibited leg power during conditioning training, supporting the belief that this parameter can be impaired when performing endurance work. Thus leg strength needs attention, as was pointed out by the eminent physiologist Jans Pieter Clarys when he noted that improving leg strength often improves overall performance. Not only is this particularly useful useful after injury, to help restore the correct balance between opposite muscle groups (such as quadriceps and hamstrings) but it is also a necessity for other aspects of performance, such as kicking or injury prevention (particularly when the muscles of posture are given attention).
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specific pre-season conditioning programme on the fitness levels of 15 senior members of an English first-division football squad. The programme used was a mixed regime of cross-country running, fartlek running (mixed pace work), aerobic interval running and hill running for aerobic benefit, which comprised 80 per cent of the volume; the remaining 20 per cent involved high-intensity shuttle running and game-specific conditioning, which is a little more intense. Throughout the pre-season period, a total of 21 days of actual training was performed, consisting of both morning and afternoon sessions lasting about one-and-a-half to two hours.
One difficulty for the coach is in deciding which type of strength training to perform within the overall programme. Thus a comparison between three types of regime was used to help identify the more suitable method. The options were: using a constant resistance, where the load remains the same but the speed of movement can vary as does the muscle length (such as a squat exercise); variable resistance, which was similar, except the load was varied; and isokinetic work. The last needs specialised equipment, where the speed of movement is maintained constant throughout the whole range of movement, which means that the load also varies. Measurement of the performance of I Repetition Max and isokinetic performance, both before and after the training programme, revealed that the variable resistance condition was most effective in the short term. For rehabilitation, however, the isokinetic condition proved to be most effective as a means of reconditioning the players in a safe and efficient manner. Taking in carbo and fluids Once the season gets underway, the emphasis of the coach tends to shift from longterm conditioning of the players to the maintenance of performance during matches. Clearly, fitness has an enormous impact here, but the importance of nutrition should not be forgotten.
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SOCCER ARTICALS A study from Chichester Institute of Higher Education examined the effects of administering carbohydrate before and during the game as a supplement. Because of the high intensity of football for a duration of 90 minutes, it is possible that maintaining carbohydrate levels throughout a match may help performance in the later stages of the game.
A similar study was also completed at the same centre, using the simulated match idea, this time examining the ingestion of fluid--in this case, water-- throughout the match. In the previous study, the same amount of fluid was consumed in both conditions; it was just the carbohydrate concentration that varied. Here, the subjects performed two trials again, one with 8ml of water per kilogram of body mass (ml/kg/min) before the test and at half time, as well as smaller doses (2ml/kg/min) every 15 minutes throughout the simulated match. The second trial had no water ingestion at all in the test period. Repeated drinking works best The results showed that body mass was maintained throughout the match in the drink condition but dropped by 2.3 per cent in the dry condition. In runners, such a drop in body mass, through fluid loss, has been shown to severely impair performance in endurance events. Similar drops in performance were also seen in these football players. Although the maximum speed of the sprints did not vary, the overall distance covered by the sprints was greater in the second half of the water trial. This shows that the overall sprinting capacity is maintained by repeated drinking in a simulated match.
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A simulated football match on a treadmill was set up, whereby subjects had to perform 30 six-second maximal sprints within a three-minute cycle of walking, jogging and running in an attempt to replicate the demands of the game. The players performed this test twice, once with a carbohydrate drink before the 'game' and at half time, and once with a placebo drink. The results showed that although the blood glucose level was higher after the carbohydrate drink, there was no significant difference in the performance variables such as maximal speeds in the match, or average sprint speed throughout the match.
Players who think they need to worry about drinking only during the warmer summer months should think again. Data collected from an English Premier League Team by Leeds Metropolitan University also examined the effects of dehydration on performance, but this time in actual matches. By carefully measuring the amount of fluid consumed by players and body mass before and after the matches, it was possible to calculate the amount of sweat loss during the matches. The average amount of weight loss during matches was 1.26kg which corresponds to a 1.54 per cent drop in body mass. However, when one considers the amount of fluid consumed in the same period, the actual loss is above 2 per cent. Given that these matches occurred during the winter, the importance of fluid replacement before and during matches is highlighted. It is particularly essential in the first few games of the season, when the temperature and sweat loss are likely to be higher. (Abstracts of these and many other studies will soon be published in the Journal of Sports Sciences, while full papers of the conference will be published in a book,
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SOCCER ARTICALS Science and Football III (E. & F.N. Spon.) Joe Dunbar
Osteoarthritis: hip injuries in footballers Hip injuries in footballers - osteoarthritis of the hip Former professional footballers are 10 times more at risk of osteoarthritis of the hip than age-matched controls, even if they haven’t sustained hip injuries during their playing careers. That’s the startling conclusion of a new British study.
Of the 68 ex-players, nine (13.24%) reported having OA of the hip, and six of these had undergone eight total hip replacements. Of the 136 controls, only two (1.47%) showed radiographic evidence of OA and none had undergone hip replacements. The most surprising aspect of these findings was that none of the ex-players with OA of the hip reported having any hip injuries during their playing careers. ‘This’, say the researchers, ‘is in contrast with OA of the knee, which is associated with previous knee surgery or injury.’ Why the difference? The researchers speculate that some apparent groin injuries sustained by footballers are actually repetitive minor hip joint injuries rather than soft tissue injuries.
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The researchers sent a questionnaire designed to assess the prevalence of osteoarthritis (OA) of various joints to the managers of the 92 league and premiership football clubs in England and Wales. Of the 74 who responded to the survey, 68 were ex-professional footballers. The self-reported prevalence of OA of the hip in those managers was then compared with radiographic evidence of OA of the hip in 136 ‘controls’ matched for age and sex.
The prevalence of OA of the hip among ex-professional footballers in this study confirms the findings of a previous study, but the comparison with non-footballers is a new development. The researchers recognise that their study has limitations – mainly the lack of scientific rigour in comparing self-reported OA with radiographicallyidentified disease. However, the findings are significant enough to point to the need for further studies comparing radiographic evidence in both groups – and, according to the researchers, such a study is already under way. Br J Sports Med 2003;37:80-81 Isabel Walker
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SOCCER ARTICALS Head injury: research suggests footballers are not at risk of brain damage Footballers are not in danger of experiencing brain damage That’s the encouraging conclusion of a major US study comparing ‘neurocognitive’ function in three groups of students at the University of North Carolina, comprising: 91 male and female foootballers, with an average of 15 seasons of prior
participation in the sport; 96 athletes, other than footballers including players of women’s field hockey,
The football players were further divided into two groups: those with and without a history of concussion. The researchers were testing the theory that extended exposure to football may be associated with chronic impairment of brain function, as put forward by some recent European studies. ‘A unique aspect of the game,’ they point out, ‘is the purposeful use of the unprotected head for controlling and advancing the ball. Reports of studies of high-level amateur and professional European footballers suggest that extended exposure to the game may be associated with chronic cognitive impairment. ‘It is further postulated’, they add, ‘that multiple subconcussive impacts to the head, such as those involved in repeated heading of the ball, may be responsible for degenerative impairment of normal brain function. Some authors have even suggested that repeated heading of the ball in game or practice situations may be comparable in effect to receiving multiple blows to the head in a boxing match or while sparring.’Such reports have apparently sent ‘shock waves’ through US youth football communities, with mandatory use of protective headgear proposed as a possible solution. Happily, though, these fears seem unfounded – at least as far as college-age athletes are concerned. For a battery of ‘neuropsychological’ tests, measuring such capacities as orientation, concentration, problem-solving, verbal association, attention and memory failed to reveal any significant differences between the groups.Even a history of concussion did not appear to predispose to mental impairment, since subjects with a history of two or more concussions were no more likely to have depressed neurocognitive performance that those with no such history. When analysis was performed by sex, the only significant difference found on any of the tests was for the verbal learning test of immediate memory recall. But this was as significant for the controls as for the footballers.The researchers conclude: ‘Our results indicate that participation in football is safe, at least up to the collegiate level, when considering its effect on neurocognitive function. Neither participation in football nor concussion history was associated with impaired performance of neurocognitive function in high-level collegiate football players with a mean age of 19 years. Although our findings need to be replicated in other settings, these results
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women’s lacrosse and men’s baseball; 53 non-athlete ‘controls’.
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SOCCER ARTICALS should provide reassurance that exposure to football during youth and adolescence does not appear to be associated with measurable deficits.’ However, it is clear that football players are at particular risk of concussion, and the researchers suggest that the focus should now be placed on ways to reduce the risk, most especially through ‘quality instruction’. …But the Risk Appears to Increase with Age
The researchers, from Florida University and the State University of New York, compared performance in four neuropsychological tests (assessing motor speed, attention, concentration, reaction time and conceptual thinking) in 32 footballers and 29 swimmers. Of the footballers, 26 were college students and six current or former professionals, with a median age of 41.5; of the swimmers, 29 were students and seven veterans (median age 42.68). The researchers were testing two hypotheses: that footballers, particularly older ones, would show poorer neuropsychological
test performance than swimmers, who are less likely to sustain sport-related brain injury; that the severity of neuropsychological deficits in footballers would correlate with the extent of their participation in the sport – ie the length of their careers and their level of competition.
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That’s the rather less sanguine conclusion of another American study, which found that footballers performed worse than swimmers on measures of conceptual thinking, with older football players scoring particularly poorly on reaction time and concentration, as well as conceptual thinking.
Their results partly supported these hypotheses, although not all the tests revealed significant differences between the footballers and the swimmers or between old and young footballers. ‘To our knowledge,’ state the researchers, ‘this is the first study to demonstrate a dose-response relationship whereby greater football experience is linked to poorer NP (neuropsychological) test performance, consistent with the hypothesis that playing football places individuals at risk for NP compromise.’ The fact that this dose-response relationship was even stronger when goalkeepers, who rarely head the ball, were excluded from the analysis supports the idea that the deficits detected are caused by football-related head trauma.
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SOCCER ARTICALS The researchers hasten to point out, though, that there is no clear evidence that such impairments, as demonstrated on formal testing, lead to practical difficulties in daily living. They conclude: ‘The younger groups’ performance leads us to concur with the assertion that, in the absence of frank concussion, younger footballers are unlikely to manifest significant NP impairment. However, the potential eventual consequences of long-continued football participation must be appreciated.’ They suggest that the risks could be minimised by such precautions as using proper size balls, coaching of correct heading technique, availability of adequate on-site care, return-to-play guidelines and annual NP screenings for athletes in head-contact sports.
Fitness for football Fitness For Football: Endurance training boosts performance in the field Football players need a combination of technical, tactical and physical skills in order to succeed. It is odd, therefore, that football research has tended to focus on technique and tactics, with little emphasis on how to develop the endurance and speed needed to become a better player. In one of the few studies which has explored the link between endurance capacity and football performance, Hungarian researchers showed that the ranking among the four best teams in the Hungarian top division was reflected by their players' average maximal oxygen-uptake (VO2max) values(1). Another investigation found a significant correlation between VO2max and the distance covered by players during matches, the number of sprints per match and the frequency of participation in 'decisive situations'(2).
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Am J Sports Med 2002 Mar-Apr 30(2), pp157-162 J Sports Med Phys Fitness 2002 Mar 42(1), pp103-107
Some studies have also shown that footballers tend to cover less distance and work at lower intensities during the second half of games than during the first half. The logical interpretation of these findings is that fatigue is limiting the players and that if they were fitter they would perform more effectively in the latter stages of their matches. None the less, until now no investigation has clearly shown that improving aerobic capacity and overall fitness boosts performance on the football field. Fortunately, that deficiency has now been remedied, thanks to the work of Jan Helgerud and his colleagues at the Norwegian University of Science and Technology in Trondheim(3). Their new study involved 19 male players from two Norwegian junior lite teams - 'Nardo' and 'Strindheim' - all of whom had been playing football for at least eight years. Both teams had been among the most successful in Norway over the past five years and six of the participants were members of the Norwegian national junior team. The players had an average age of 18 and mean mass of 72kg (158lb).
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At the beginning and end of the eight-week study period, all players were tested for VO2max, lactate threshold, vertical jumping height, 40m sprint ability, maximal kicking velocity and the technical ability to kick a football through defined targets. After eight weeks of twice-weekly interval training, the players in the training group had improved VO2max by almost 11%, from 58.1 to 64.3 ml.kg-1.min-1; meanwhile control group players had not upgraded VO2max at all! Similarly, lactate-threshold running speed improved by 21% and running economy by 6.7% in the training group, while controls again failed to improve at all. Clearly the players in the training group were gaining tremendous physiological benefits from just two aerobic workouts per week! Happily, all of these physiological details translated into some markedly improved performances on the football field: interval-trained athletes increased the total distance covered during games by 20% (from 8,619 to 10,335m) and also doubled the number of times they sprinted during games (a sprint being defined as an all-out run lasting at least two seconds). Furthermore, after eight weeks of interval training the number of involvements with the ball per game increased by 24%, from 47 to 59. (Involvements were defined as situations in which a player was either in physical contact with the ball or applying direct pressure to an opponent in possession of the ball.)
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Aerobic interval training v extra technical training Players within each team were randomly assigned to either a training group or a control group, so that each team had members in both groups. In addition to their regular football training and play (four 90-minute practices and one game per week), members of the training group performed aerobic interval training twice a week for eight weeks. Each interval workout consisted of four discrete four-minute work intervals at 90-95% of maximal heart rate, with three-minute recoveries at 50-60% of max heart rate. Technical and tactical skills, strength and sprint training were emphasised in most practice sessions, and about one hour of each practice was devoted to mock football games. While the training group members carried out their four-minute intervals, control soccer players engaged in extra technical training, including heading drills, free kicks and drills related to receiving the ball and changing direction.
Interval training also boosted the athletes' overall ability to play at high intensity; after eight weeks of interval work, they were able to perform at an average of 85.6% of max heart rate during their games, compared with just 82.7% beforehand. Training group members also spent 19 minutes longer than controls in the high-intensity zone (ie above 90% of max heart rate) during an actual game. Of course, interval training isn't a panacea, and sprint speed, squatting strength, bench-press strength, jumping height, kicking velocity and the technical shooting and passing test were unchanged by the aerobic work, as you might expect. None the less, this very simple interval training programme (with just two workouts per week and four 4-minute intervals @ 90-95% of max heart-rate per workout) produced some dramatic improvements in overall play. Put simply, boosting VO2max, lactate threshold and running economy with interval routines gave the players an
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enhanced ability to cover longer running distances at higher intensities during games and to be involved with the ball more frequently and thus play a greater role in deciding the outcomes of competitions. No footballer can argue that he/she does not have enough time for such additional training, which should be included in all overall programmes. Interestingly enough, the VO2max ultimately attained by the interval-trained players (64.3 ml.kg-1.min-1) is above the average VO2max reported for experienced international footballers, suggesting that a large number of football players could benefit from aerobic training. Athletes in many other disciplines which are not traditionally viewed as endurance sports might also benefit from the kind of interval training carried out by the Norwegian football players. In particular, interval work should offer advantages for those involved in rugby and basketball. Recent research carried out at the Victoria University of Technology in Australia revealed that basketball places huge demands on the cardiovascular system, suggesting that aerobic capacity improvements might upgrade the quality of play(4). In this study, eight players (three guards and five forwards or centres) from the Australian National Basketball League were monitored during league competition and practice games. Each competition consisted of four 12-minute quarters, with a 15minute break at half time and two-minute breaks between quarters. Maximal aerobic capacity (VO2max) was determined for each player. When the ball was in play, there was a change in movement category (for example, from medium-intensity shuffling to sprinting) every two seconds, and 'very intense' activity accounted for almost 30% of court time. This translated into a heavy load on the players' cardiovascular systems, with heart rate during play averaging 89% (compared with 86% of max for the interval-trained Norwegian football players and 83% for the Norwegian controls). Basketball players' heart rates were above 85% of max for at least 75% of court time. Even more impressively, cardiac beating was in the 95-100% of max range for 15% of court time and in the 90-95% range for 35% of total time. During free-throw shooting, heart rates recovered to around 70-75% of max. Interestingly, blood-lactate levels were also quite high in the basketball players, with average lactate concentration at 6.8 millimolars (mM)/litre. Somewhat surprisingly, lactate levels as high as 13 mM/litre were recorded in some of the athletes, comparable to those seen in top-level sprinters after 400m races. These findings suggest that lactate-threshold improvement might benefit basketball players' performances. Overall, there were about 105 'high-intensity' efforts per player per basketball game, and each such exertion (whether it involved fast running or intense side-to-side shuffling) lasted for about 14 seconds. Thus, a basketball game was a bit like carrying out an interval workout with 105 14-second reps. Recoveries between repetitions were short, since intense efforts occurred every 21 seconds. As it turned out, the Australian basketball players had average VO2max readings of 61 ml.kg-1.min-1, compared with 64.3 in the interval-trained football players and 59.5 in the control group. This suggests not only that basketball itself boosts VO2max but also that improvements in VO2max might foster better play, just as it does in football. What other interval workouts besides the Norwegians' 4x4-minute scheme might be beneficial for football and basketball enthusiasts? Clearly, some of the renowned French scientist Veronique Billat's 'v VO2max' sessions would be helpful, since they are very intense in nature and lead to enhancements in VO2max, lactate threshold, and running economy.
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Owen Anderson References Science and Football, T Reilly, A Lees, K Davids, and WJ Murphy (Eds). London: E & F N Spon, 1988, pp 95-107 2. Proceedings of the 1st International Congress on Sports Medicine Applied to Football, Rome, 1980, L Vecchiet (Ed) Rome: D Guanillo, 1980, pp 795-801 3. Medicine and Science in Sports and Exercise, vol 33(11), pp 1925-1931, 2001 4. Running Research News, vol 12-3, pp 11-12, 1996
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Two of Veronique's workouts should be particularly beneficial: l The 30-30. To perform this workout, athletes should simply warm up effectively, then alternate 30 seconds of running at close to max intensity with 30 seconds of easy ambling. Initially, they should go for 10 reps, but as aerobic capacity improves they can simply keep going until fatigue kicks in; l The 3-3. This is like 30-30, except that athletes alternate three minutes of hard running with three minutes of loping. The pace for the strenuous three-minute intervals should be determined by the best-possible speed achieved during a sixminute test. (Naturally, 're-tests' of six-minute velocity will be needed every 4-6 weeks-or-so, since running capacity should improve.) Few athletes should try to complete more than five three-minute intervals per workout. What's the bottom line? In several key ways, football and basketball count as 'endurance sports', since they place a high demand on the cardiovascular system, and since performance ability appears to hinge on physiological variables such as VO2max, lactate threshold and running economy. Thus, performing the types of interval workouts used by endurance athletes should be helpful to players of both sports.
Football training: how to take a penalty kick How to win the penalty shoot-out mind game The classic mind game of soccer penalty-taking begins when the referee points to the spot. Anticipation, strong nerve, cool head, firm resolve - all these factors come into play in a brief but highly intense drama. Will the keeper second-guess the striker? Will the kick - as happens surprisingly frequently - fly high over the goal? Science has now come to the aid of goalies with research which may help them to stay calm. It seems that in the split second before the striker hits the ball, the orientation of his or her hips indicates which way the ball will fly. The results were presented at the second Asian Congress on Science and Football in Kuala Lumpur, Malaysia. Mark Williams, head of science and football at Liverpool John Moores University, explained: 'If the taker's hips are square-on to the goalkeeper in a right-footed kicker, the penalty tends to go the right-hand side of the keeper. If his hips are more 'open', the kick tends to go the left.'
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SOCCER ARTICALS His study investigated saving strategies by showing goalkeepers life-sized video footage of strikers before and during penalties. He stopped the film four times: 120 milliseconds before the kick; 40 milliseconds before; at the point of impact; and 40 milliseconds afterwards. Each time, he asked the keepers to predict the outcome. Semi-professionals were consistently better than unskilled amateurs at guessing which of four target spots in the goal the ball would hit. At 120 milliseconds before impact, half the semi-pros guessed correctly. The success rate rose to 62 per cent 40 milliseconds before, and 82 per cent at impact. At each stage, the amateurs lagged ten percentage points behind the semi-pros.
The question is, will this information make things harder for strikers, or will it introduce a new dimension to the mind game as strikers try even harder to disguise their intentions?
How nutrition can help soccer players overcome the second-half slump New research suggests soccer players need better nutrition Although soccer is the most popular sport in the world, with over 120 million amateur players worldwide, scientific research concerning the nutritional needs of soccer players has been scant. Fortunately, new investigations are being conducted, and the up-to-date research suggests that soccer players should eat and drink like marathon runners!
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Williams reported that other visual cues include angle of the striker's run-up and the orientation of the non-kicking foot. Ian Franks and Todd Harvey at the University of British Columbia identified this latter factor as the crucial cue in a study of 138 penalties in World Cup competitions between 1982 and 1994. The non-kicking foot pointed to where the ball would go 80 per cent of the time.
The link between soccer players and long-distance endurance athletes seems odd at first glance, since soccer is a game involving sudden sprints and bursts of energy rather than continuous moderate-intensity running, but the connection doesn't seem so extraordinary when one considers what happens during an actual soccer match. In a typical contest, soccer players run for a total of 10-11 kilometres at fairly modest speed, sprint for about 800-1200 metres, accelerate 40-60 different times, and change direction every five seconds or so.Although soccer players don't cover a full marathon distance (42 kilometres) during a game, the alternating fast and slow running which they utilize can easily deplete their leg-muscle glycogen stores. For example, just six seconds of all-out sprinting can trim muscle glycogen by 15 per cent, and only 30 seconds of upscale running can reduce glycogen concentrations by 30 per cent! The high average intensity of soccer play (studies show that topnotch players spend over two-thirds of a typical match at 85 per cent of maximal heart rate) accelerates glycogen depletion. Plus, the time duration of a soccer match, 90 minutes, is more
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They're half-starved! Unfortunately, many soccer players don't seem to be aware of the importance of dietary carbohydrate. Studies show that large numbers of players eat only 1200 calories of carbohydrate per day, far below the optimal level of 2400-3000 carbohydrate calories. As a result, many players BEGIN their competitions with glycogen levels which are sub-par. Players who start a match with low glycogen usually have little carbohydrate left in their muscles by the time the second half starts.That leads to bad performances during the second half. Glycogen-poor soccer players usually run more slowly - sometimes by as much as 50 percent - during the second halves of matches, compared to the first. In addition, total distance covered during the second half is often reduced by 25 per cent or more in players who have low glycogen, indicating that overall quality of play deteriorates as glycogen levels head south. Compared to competitors with normal glycogen, low-glycogen players spend more time walking and less time sprinting as play proceeds.That's why taking in carbohydrate DURING competition can pay big dividends. In recent research carried out with an English soccer team, players consumed a glucose-containing sports drink during 10 of their matches but swallowed only an artificially flavoured, coloured-water placebo during 10 other competitions. When the players used the glucose drink, the team allowed fewer goals and scored significantly more times, especially in the second half. When the placebo was ingested, players were less active and reduced their contacts with the ball by 20-50 per cent during the final 30 minutes of their games. A separate study showed that swilling a glucose solution before games and at half-times led to a 30-per cent increase in the amount of distance covered at high speed during the second half of a match.However, just sipping a sports drink at random before matches and at half-time probably won't do much good, because soccer players must be sure they take in ENOUGH carbohydrate to really make a difference to their muscles. An excellent strategy is to drink about 12-14 ounces of sports drink, which usually provides about 30 grams of carbohydrate, 10-15 minutes before a match begins. The same amount should be consumed at half-time, although players may rebel at both intake patterns because of perceptions of stomach fullness. The important thing to remember is that through experience - trying out these drinking strategies on several different occasions during practices - the intake plans will gradually become comfortable and they will help reduce the risk of carbohydrate depletion.
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than enough to empty leg muscles of most of their glycogen. In fact, research has shown that soccer players sometimes deplete 90 per cent of their muscle glycogen during a match, more than enough to heighten fatigue and dramatically reduce running speeds.
Tapering is important, too Soccer players should also eat a small meal containing at least 600 calories of carbohydrate about two hours before competition. 600 calories is the approximate amount of carbohydrate in three bananas and four slices of bread (eaten together).Players should also try to 'taper' for a few days before matches, reducing their intensity and quantity of training in order to avoid carbohydrate depletion. During the taper and during all periods of heavy training, soccer players should attempt to ingest 9-10 grams of carbohydrate per kilogram of body weight ( 16-18
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calories per pound of body weight) each day. 'Grazing' - eating two to four daily highcarbohydrate snacks in addition to three regular meals - can help players carry out this high-carbo plan successfully.However, carbohydrate is not the only nutritional concern for soccer players.Fluid intake is also critically important. Various studies have shown that soccer players lose - through their sweat glands - from two to five litres of fluid per game. Even the lower figure could raise heart rate and body temperature during a match and might reduce running performance by about 4-5 per cent for a typical player. Fortunately, the sports-drink-intake plan described above - coupled with sips of sports drink during injury time-outs - can help to reduce the impact of dehydration.Although water and carbohydrate must be taken onboard, soccer players don't need to worry about replacing electrolytes during play. Sweat is a dilute fluid with low concentrations of electrolytes, and most players can obtain enough electrolytes - including salt - from their normal diets.However, the presence of salt in a sports drink can enhance the absorption of water and glucose. Most commercial drinks have about the right concentration of sodium; if you're making your own beverage, you should be sure to mix about one-third tea spoon of salt and five to six tablespoons of sugar with each quart of water that you're going to be using. After all matches, players should attempt to ingest enough carbohydrate-containing sports drink to replace all the fluid they've lost during competition. After strenuous workouts, water should also be replaced, and soccer athletes need to eat at least 500 calories of carbohydrate during the two hours following practice in order to maximize their rates of glycogen storage.('Carbohydrate, Fluid, and Electrolyte Requirements of the Soccer Player: A Review,' International Journal of Sport Nutrition, vol. 4, pp. 221236,1994) Owen Anderson
The eyes: soccer The Eyes: Soccer: What makes a topnotch football player different from a mediocre performer? One key difference is in the way their eyes move, according to researchers at the University of Liverpool and the University of Manchester.
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High-quality players survey the field of play for clues about what their opponents will try to do in a manner which varies strikingly from the visual search patterns used by less-experienced performers.To find out exactly how soccer players become skilled at anticipating events on the field, the English scientists studied 15 experienced and 15 inexperienced male soccer players. The experienced athletes had 13 years of playing experience and had played an average of 640 competitive matches, while the inexperienced subjects had played for five years in an average of 73 matches. The experienced players included eight college first-team players and seven professionals; college third-team and recreational players comprised the inexperienced contingent. All 30 players watched test films containing 26 soccer action sequences, selected from a sample of college and professional soccer matches. The games had been filmed from a position behind and above the goal, which allowed the entire field of play to be viewed on film. As the players watched the matches, their eye movements were
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captured with a special recorder. As a pattern of play developed, a black square highlighted a player on the viewing screen; when the ball was passed to this player, the subjects had to verbalise as quickly as possible the player to whom the next pass would go. Analysis of the athletes' reactions demonstrated that the experienced players were far better at anticipating final-pass destinations and made significantly quicker responses, compared to their less-experienced counterparts. How were they able to do it? The eye-movement recorder showed that the experienced players conducted a more extensive visual search of the field of play as they watched the match. For one thing, they shifted their gaze from one part of the field to another about 25-per cent more often than their inexperienced peers. Experienced players were also better at discerning relevant portions of the field of play. While inexperienced players fixated on the ball and the player actually passing the ball, experienced players focused on peripheral aspects of play, such as the movements of other players not in close contact with the ball - players who were moving into open areas of the field in which they might eventually receive a strategic pass. The Liverpool-Manchester scientists recommended that football coaches show game films to their players while stopping the film frequently in order to highlight important 'off-ball' movements. As players learn to stop ball watching' and develop a knack for determining where everyone on the field is going, they will learn to anticipate play development. Then their only task will be to learn to make the right decision about how to stop or assist the ensuing attack on the goal. ('Visual Search Strategies in Experienced and Inexperienced Soccer Players,' Research Quarterly for Exercise and Sport, vol. 65(2), pp. 127-135, 1994)
Speed parachutes Speed Parachutes: Displaying their bold maize and blue colors, the chutes billow out behind runners during workouts, attached by cords to the athletes' chests.
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As long as there are no gale-force winds, chute-users don't become airborne; in fact, their running velocities slow considerably because of the increased air resistance created by the chute. It's a bit like running uphill, except that instead of working against gravity you're fighting against the air hitting the inside of your trailing parachute.But is it really a good idea to use a speed chute during training? Chute proponents claim that the device strengthens leg muscles and leads to more powerful performances, especially over competitive distances of one mile or less. Even chute critics have to admit that the contraption does provide 'specific' training, which is always a hallmark of wise workouts. After all, you do run when you're wearing the chute, and running well is your ultimate goal. In that regard, chute use is a better form of resistance training than, say, lifting a weight with the leg muscles while the body is in a standing or sitting position. However, it's easy to criticize the chutes, too. Let's face it: once you have a chute strapped to your chest, you are definitely going to run more slowly during training, compared to running chuteless. As we all know, training more lethargically is
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definitely not the way to become a better runner, so in this regard, chute training looks stupid. Realistically, though, you don't have to use the chute every day. Even if you became a chute fanatic, you could still do your regular high-speed work on days when the chute remains in your gym bag. Plus, recent research with the weight vest, another device which, like the speed chute, slows running speeds but increases the stress on leg muscles, found that such training could produce unexpected gains in running prowess. Although speed chutes have been extolled in various advertisements, no chute research has been published in scientific journals, so runners have been basically clueless about the colorful contrivances. Fortunately, that's all changed now, thanks to the untiring efforts of Matthew Taylor, an exercise physiologist who now works in the Human Performance Laboratory at the William Beaumont Army Medical Center in El Paso, Texas. While at St. Cloud State University in Minnesota, Taylor began working with 14 school sprinters, aged 15-18. All of the athletes trained four times per week for a period of six weeks, but only half of the runners actually worked out with the speed chute.Two days per week, the groups trained in a very similar manner, using workouts which emphasized stretching, sprint drills, plyometrics, stair climbing, hurdle jumps, table jumps, quick-feet drills on a 'Port-A-Pit', lateral hops, full-court basketball, high-knee drills, and butt flicks. Speed chutes weren't used on these days. On the other two training days, the speed-chute group completed sprint intervals using a speed chute while the other athletes ran similar sprint intervals without the chute. During early stages of the six-week training period, the speed-chute runners completed 200-metre intervals in a very interesting manner; they ran the first 100 metres of the interval with the chute attached but then released the chute at the 100metre mark and ran unencumbered over the last half of the interval. Average time per 200 meters was about 26-28 seconds. The no-chute group ran the same 200-metre intervals without chutes, and their times were also in the 26-28 second range. This meant that chute-group members were actually working harder during the interval workouts, since they covered the 200-metre distance in the same time needed by the chuteless athletes, but against increased air resistance. Toward the end of the six-week period, the intervals were shortened and speeded up, especially for the chuteless runners. After a 10-metre flying start, chute-group athletes ran 50-metre intervals in about 6.5 seconds each, with chutes attached for the whole interval. Meanwhile, after the same running start, chute-free athletes ran 50-metre intervals in six seconds (a pace of 24 seconds per 200 metres), with no chutes to tire their leg muscles. Thus, near the end of the study, the no-chute runners were actually running a little faster during their workouts, compared to the speedchute trainers. During an average workout, about eight of these 50-metre intervals would be completed per session, with 45-60 seconds of rest between efforts. Improvements? After six weeks of training, speed-chute runners improved their 55metre race times by an average of .23 seconds, from 6.26 to 6.03 seconds, a pretty respectable improvement. However, the no-chute trainers fared just as well, lowering 55-metre clockings by .22 seconds from 6.12 to 5.90 seconds. In other words, use of the speed chute provided no special benefits during training; sprint performances improved just as much in the runners who abstained from speed chutes altogether. The bottom line? Using a speed chute does no harm, as long as the overall quality of training is kept high. However, performance problems may arise if the chute consistently reduces running speeds during interval training. On the positive side,
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SOCCER ARTICALS speed-chute use is fun and provides an interesting break from routine training. However, there's still no solid evidence that the utilization of speed chutes will heighten sprint performances, compared to conventional training. 'Effects of Speed Chute Training on Sprint Performance,'Medicine and Science in Sports and Exercise, vol. 26(5), Supplement, p. S 64, 1994
Soccer Refs compete at the highest level, footballers must be supremely fit. But the next time you are sitting in front of the TV, marvelling at the athleticism of the players, spare a thought for the ref, who has to make split-second decisions while keeping up with the increasingly fast run of play. How hard do these refs actually work? Keen to answer this question, The Italian Football Federation carried out an extensive four-year study examining the work rate profile of their own high-level soccer referees. More than 30 referees enrolled in the Serie A and B Italian championships took part in the study. Each referee was observed between one and six times for a total of 96 matches, using sophisticated video analysis equipment. The key results were as follows: 1. the referees stood still for 14.6% of the total time played; 2. the total distance covered over an entire match was 11,469m; 3. this distance was covered in a variety of runs (forward, backward, sideways) and at various intensities from walking to high intensity (18.1-24k/h) and maximal intensity (24k/h) runs. You may still not be too impressed, but remember that football referees are not professionals and hold down quite separate full time jobs. Despite this and the fact that they are usually older than the players they officiate over, they are still expected to keep up with the run of play no matter what the tempo.
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Top flight soccer refs cover 11k-plus per match, says new studyTo
The Italians concluded that refereeing top-flight matches is a demanding activity, which is predominantly aerobic, although the anaerobic system plays an important role at certain times. As the players get fitter so must their refs; it's a tough job but somebody has to do it! The Journal Of Strength and Conditioning Research 15 (2) 167-171 Nick Grantham
Training dietary regimes Training Dietary Regimes: You can lead a footballer to a proper diet, but can you make him eat it? While the average distance covered by a top-class outfield player during a 90-minute match is over 10,000m, at an average speed of over 7km per hour, these figures do not accurately represent the full demands placed on a player. In addition to running, a
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The keeper The specific demands of the different positions within a team are not as clearly defined as in some other team sports, such as rugby union. The obvious exception to this is, of course, the goalkeeper. A keeper relies little on the aerobic system for energy production since all the important phases of play for him last a relatively short time. The key performance quality of the keeper is probably agility, and this can be broken down further to include speed, power, strength and flexibility. If he happens to be tall, it's clearly an added bonus! Popular training programmes for keepers include repetitions of short sprints performed at maximal speed, with many changes of direction involved. Obviously, an element of skill can be built into this training by having to save a bombardment of shots at goal. This way, another important constituent of training is then automatically introduced, namely, the ability to regain one's feet in order to save a follow-up shot at goal. However, to gain the edge in physical development, the keeper should also train away from the pitch so that upper and lower body strength and power can be improved in the weights room. In addition, plyometric training lends itself perfectly to improving the qualities necessary for agility around the goal mouth. Plyometric training does need to be conducted correctly (see, for instance, PP 42, March 1994) which includes the provision of generous rest periods between sets of exercises, but if done so can produce some significant improvements in the ability to move one's own body weight at speed Outfield players As far as the rest of a soccer team goes, the differing demands are less obvious. However, a systematic analysis of soccer matches on video has shown that midfield players tend to cover the most distance, and other studies have - not surprisingly shown these players to have the highest VO2max scores, and to show the least fatigue when performing many repeated sprints in succession. Compared to forwards and defenders, midfield players tend to have a more continuous involvement in the game. However, while forwards and defenders usually have more time to recover between sprints, they also need to perform those sprints at a faster speed to be successful in their crucial phases of play
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player must jump, change direction, tackle, accelerate and decelerate, etc, and each of these individual tasks requires an energy input over and above that required simply to cover a similar distance at a constant speed. Scientific investigation has shown that the true demands on a player can be approximated at roughly 70%VO2max. This is based on evidence of heart rate, sweat loss, increase in body temperature, and depletion of carbohydrate stores within the muscles (intramuscular glycogen)
Implications for training should become apparent. Clearly, the midfield players need more of an all-round fitness profile, with an emphasis on both aerobic and anaerobic capacity. Aerobic capacity relates to sustained performance (20-40 minutes), or performance during lengthy repetitions, each of 2-3 minutes in duration. Anaerobic capacity can be related to performance of a repeated nature, but with work/rest intervals of equal length, and not over 30 seconds. The players regularly involved in attacking/ defending situations will need more training emphasis on speed. Speed training can itself be broken down into at least two phases - an acceleration component and a maximal speed component. For
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Match-play Moving away from training methods for a moment but continuing the analysis of the physical demands of the game, there is an interesting form of player behaviour that playing experience seems to encourage. It is a phenomenon that many players will recognise as common without perhaps understanding why. The behaviour in question is the avoidance of prolonged high-intensity activity that would require a corresponding long period of recovery - which can rarely be afforded in a competitive situation. For instance, if a defender is involved in high-intensity activity as he assists in an attacking phase of play, he often will not attempt to return to his defending position in time for the immediate counter-attack. While this might be perceived as laziness, it may benefit both the individual player and the team in the longer term, providing the rest of the team has sufficient cover to deal with the counter-attack. Sound physiological reasoning provides the basis for this. It has been shown that short periods of intense exercise (eg, less than 15 seconds), when interspersed with rest periods of similar duration, produce a fairly low build-up of lactic acid in the muscles (a strong indicator of fatigue) even when this activity pattern is continued for some time. However, periods of intense exercise of about 30 seconds or more, even when accompanied by equal rest periods of 30 seconds (such that the work:rest ratio is till 1:1 as in the previous example), produce a far higher concentration of lactic acid in the muscles and also greater fatigue
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improvements in acceleration, repeated sprints of not less than six seconds in duration, performed from a standing or walking start, will be useful in training. This will help develop the neuromuscular function of the athletes. For development of maximal speed, a gentle increase in speed to about 85 per cent followed by a sustained burst at maximum speed for about six seconds will produce more specific improvements. This will help develop both the metabolic and neuromuscular qualities of the muscles involved. Put simply, to improve acceleration, accelerate as fast as possible in training. To improve maximal speed, the length of time spent running at current maximal speed during training should be increased. A relatively gentle acceleration phase before a sustained burst can best achieve this. If the coach can accomplish these sorts of training goals by using drills which involve ball skills, then the players will become used to performing the skills under conditions of fatigue. As many will appreciate, it is under conditions of fatigue and mental pressure such as a competitive match that skills often become lost - unless they are both well-drilled for their own sake and practised under simulated conditions of fatigue
This situation is exactly what the experienced player is trying to avoid when he decides to return more slowly to his main position on the pitch. However, this obviously requires a large degree of teamwork, with team-mates prepared to cover for the defender concerned. If a team can achieve this sort of cooperation, it helps reduce player fatigue and increases performance capacity throughout the match as a whole. Clearly the role of the coach is paramount in organising this sort of team approach in spreading the workload, especially with inexperienced players. Indeed, some younger players may be almost too enthusiastic for the good of their own and the team's subsequent performance Nutrition
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SOCCER ARTICALS As already mentioned, the physical demands of the game are sufficiently high so as to require a high rate of energy production. Whatever the sport, this can only be done by the breakdown of carbohydrates, and soccer is no exception. This means that players should pay particular attention to this aspect of their diet - more especially when considering the notorious practices of soccer players when they are given no guidance about what to eat. The heavy training/match schedule that the British game involves only serves to increase the need for carbohydrate intake
The work carried out some years ago by Jacobs and colleagues ('Muscle glycogen and diet in elite soccer players', European Journal of Applied Physiology, 1982, vol. 48, pp297-302) illustrates the potential pitfalls of a low-carbohydrate diet. These researchers studied players in the Malmo soccer team in Sweden - the side had finished as runners-up in the European Cup the previous season. The players consumed just 47 per cent of dietary energy as carbohydrates - well below the recommended values. Muscle glycogen stores were assessed immediately after a national league match (Day 1), and again 24 hours later after no training (Day 2), and 48 hours after the match after a very light training session (Day 3) Normal muscle glycogen stores of the general population are approximately 70-90 mmol.kg-1 wet weight. The average values for the Malmo team were 46, 69 and 73 mmol.kg-1 wet weight on the three days. There is no reason why the players could not have refilled their muscle glycogen stores to pre-match levels within 24 hours if they had consumed a high-carbohydrate diet. Experiments have shown that, for highly trained athletes, a muscle glycogen level of well over 100 mmol.kg-1 wet weight is quite possible to achieve following two or three days of light training. The reason the soccer players didn't reach this sort of level was undoubtedly due to the lack of carbohydrate in their diet. The importance of high muscle glycogen stores for performance in events lasting longer than 60 minutes has been demonstrated by numerous researchers. Specifically in relation to soccer, the diets (and hence the muscle glycogen stores) of players involved in an exhibition match have been manipulated, with those players having higher muscle glycogen stores before the match also covering a greater distance at a faster pace during the match. This effect was particularly noticeable towards the end of the match when glycogen always become lowered - and many goals are often scored as the game tends to open up. So a high-carbohydrate diet leads to increased muscle glycogen stores, which in turn leads to a greater distance covered during the final stages of the match, which in turn leads to your team scoring the winning goal in injury time! Well, not always, maybe, but you can increase the chances of it happening by taking a close look at players' diets
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When discussing this subject, it is usual to express the form of the energy consumed as percentages (proportions) eaten as carbohydrate, fat and protein. While the typical diet for the general British population is about 40% carbohydrate, 45% fat and 15% protein, the recommended dietary proportions for a soccer player would be roughly 65% carbohydrate, 20% fat and 15% protein. However, the typical diet of the soccer player is actually very similar to that of the general population - too little carbohydrate and too much fat
Alun Williams
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SOCCER ARTICALS muscle building Muscle building: Squats, leg press or knee extensions - which exercise is best for the quads?
The squat and the leg press are considered to be a different type of exercise from the knee extension. The squat and the leg press are known as closed kinetic chain exercises (CKC), whereas the knee extension is considered an open chain kinetic exercise (OKC). CKC exercises are distinguished by the foot being fixed and the knee joint moving in conjunction with the hip and ankle in a predictable manner. With the squat, for example, the foot is on the floor. and ankle, knee and hip all flex and then extend in sync. OKC exercises, on the other hand, are distinguished by the foot being free to move and the knee joint working independently of any other joints. With the knee extension, the hip joint is fixed and the knee flexes and extends with the foot freely rotating. (Recently, researchers have argued that this classification system of exercises is too simplistic, but for the purposes of this article, the simple distinction is sufficient.) What the researchers say Researchers and physiotherapists seem to be agreed that CKC exercises are superior to OKC ones. CKC knee exercises are considered safer and more effective since they place less strain on the anterior cruciate ligament (ACL) and elicit a hamstrings cocontraction together with the quadriceps. Researchers from the Mayo Clinic (New York) showed that leg press placed no strain on the ACL and elicited significant hamstring co-contraction, whereas the knee extension placed strain on the ACL at 30째 of flexion. The decreased ACL strain makes CKC knee exercises important for ACL rehabilitation programmes.
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Training the quadriceps muscles is an integral part of most sports strength programmes. The quadriceps are important for cycling, swimming, running, jumping, sprinting, throwing - in fact, virtually every full-body athletic movement. Three of the most common quadriceps exercises are the squat, the leg press and the knee extension. But although all three exercises target the quads, they all vary in terms of knee joint forces, muscle activity and functionality. There are even variations within an exercise through changes in technique or equipment.
The Mayo Clinic team also argue that CKC exercises are superior because they are more functional than OKC exercises. Walking, jumping and running movements all involve the kinetic chain of ankle, knee and hip. Thus it is advantageous to strengthen the quadriceps in a similar manner to real movements - specificity of training is an accepted principle in sports science. During the squat and leg press, the knee and hip extend together. While the knee extends, the rectus femoris shortens and the hamstrings lengthen, but while the hip extends, the rectus femoris lengthens and the hamstrings shorten. The result is a simultaneous concentric and eccentric contraction at the opposite ends of each muscle. This is known as the 'concurrent shift', and is a specific neuromuscular pattern which occurs during all multi-joint leg movements. This concurrent shift does not take place in OKC exercises. Theoretically, training the quadriceps in isolation, without normal muscular recruitment patterns, could lead to inefficient neuromuscular coordination in athletic movements. Training movements
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SOCCER ARTICALS that involve the concurrent shift are very important, so CKC knee exercises are recommended.
More support the squat Kevin Wilk and a team from the American Sports Medicine Institute investigated the EMG activity of the quadriceps and hamstrings during the squat, leg press and knee extension. They also used experienced lifters and determined the 12-repetition maximum weight for each exercise. Like Signorile, they found that the squat produced the most quadriceps activity, peaking at 60 per cent of maximum activity levels. The leg press produced slightly less, peaking at 52 per cent, with the knee extension less still, peaking at 46 per cent. Wilk's team also investigated the knee joint forces during the exercises. They confirmed the Mayo Clinic findings regarding ACL strain forces. The CKC exercises, the leg press and squat, placed no strain on the ACL, whereas below 40째 of flexion the knee extension did place a strain on the ACL. However, the leg press and squat did place a strain on the posterior cruciate ligament (PCL), and should therefore be avoided by PCL injury patients. The leg press and squat also produced significantly greater knee compression forces than the knee extension, with the squat producing the highest. Compression force refers to the vertical force between the surfaces of the femur and tibia, and excessive compressive forces can cause knee injury.
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Other studies have compared the muscle electromyographic (EMG) activity during the squat, leg press and knee extension exercises. EMG activity is an objective measure of the amount of muscle activity during the exercise. This allows exercises to be compared. Joseph Signorile and a team from the University of Miami investigated the EMG activity of the quadriceps during the squat and knee extension. They used experienced lifters and determined the 10-repetition maximum weight for each exercise. This guaranteed that both exercises required the same relative effort. The team found that the squat elicited significantly more quadriceps EMG activity compared to the knee extension. Signorile et al concluded that because of this the squat should be seen as the superior quadriceps exercise, especially as it is a more functional movement.
Wilk et al also found that the squat was the only exercise of the three to elicit a significant hamstring co-contraction. During the squat, the hamstring activity peaked at 36 per cent of maximum compared with the leg press and knee extension in which hamstring activity peaked at 12 and 13 per cent respectively. This finding contradicts the Mayo Clinic research which showed a hamstring co-contraction during the leg press. This suggests that just because the leg press is a CKC exercise, it does not guarantee that there will be significant hamstring co-contraction. Other factors, such as body position and angle of force application, affect whether CKC exercises elicit cocontraction of the hamstrings, and are therefore functional to other movements. The athlete's position is important In a recent review paper, Wilk and his team summarised findings from research into co-contraction of hamstrings during leg press and squat exercises. The most important factor seems to be the technique used or body position of the athlete when
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SOCCER ARTICALS performing the exercise. For example, with the squat performed normally with a bar across the back of the shoulders, as the knee and hip flex, the trunk leans forward. At the bottom of the lowering phase, the bar is positioned in front of the hips. This means that, as well as the quadriceps working to extend the knee, the hamstrings must work to extend the trunk back upright.
With a lying leg-press machine, the body position changes once again. The feet are placed above the hips and so the weight is in front of the hips. Thus, when the leg extends, the hamstrings must work to extend the hip along with the quadriceps which are working to extend the knee. So with the lying leg press there is hamstring cocontraction as with the squat. This is the type of leg press the Mayo team used in their study, which showed leg-press hamstrings activity. Changes in squat technique can reduce the hamstrings co-contraction - for instance, by placing one's back against a support. This change will isolate the quadriceps since the trunk is supported and the hamstrings do not have to work to keep it upright. Other studies have shown that wide-stance squats produce more hamstrings and gluteal activity, and narrow-stance squats more quadriceps activity. Again, changes in technique result in different patterns of muscle activity. From the research discussed above, we can draw some conclusions about the efficacy of the three quadriceps exercises.
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By contrast, with the seated leg press, the athlete sits with the body fixed upright and the footplate is level with the hips. Thus when the legs extend, the quadriceps work to extend the knee but the hamstrings need not work, because the trunk is fixed and the weight is in line with the hips. This biomechanical difference explains why Wilk found co-contraction with the squat and not with the leg press.
1. The squat This is probably the best exercise for the quadriceps. Studies have shown that the squat elicits the highest quadriceps EMG activity compared to the leg press and the knee extension. This means that the squat works the quadriceps the hardest. In addition, the squat is a CKC multi-joint exercise which elicits co-contraction of the hamstrings. Researchers have argued that this makes the exercise functional to athletic movements and therefore a sports-specific strength exercise. The cocontraction of the hamstrings means that the squat trains the 'concurrent shift' pattern, which is very important biomechanically. The squat is also safe for ACL patients, although it is not safe for PCL patients. Variations such as narrowing the stance will concentrate activity on the quadriceps, while widening the stance will allow more gluteal and hamstrings activity. Leaning against a back support will isolate the quadriceps. The major disadvantage of the squat is that it results in the highest knee-joint compression forces of all the exercises. This may cause problems for those with weak knees because of the extra pressure on the surfaces of the femur and tibia. For this reason, a correct squatting technique is vital to safety. Athletes also need to be strong
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SOCCER ARTICALS in the low back and abdominals, because the squat works the low-back muscles hard and a high intra-abdominal pressure is required to support the spine. For heavy squatting, the athlete will need a training partner or a squat frame to train safely. I conclude from the evidence that the squat is a very effective and sports-specific quadriceps strengthening exercise. However, it is probably best for well-conditioned athletes only.
The major disadvantage of the leg press is that it is not necessarily functional simply because it is a CKC multi-joint exercise. Wilk showed that with the seated leg press there was no hamstrings co-contraction. This means the concurrent shift pattern is not trained as it is with the squat. However, hamstring co-contraction is possible with a lying leg-press position with the feet placed higher than the hips. The lying leg press would be a good sport-specific exercise, just like the squat, only a little safer and easier. The complication with the lying leg press is that the feet should not be placed too high. Ideally, they should be placed so that they are above the hip but level with the knee when the knee is fully extended. In this position, both the quadriceps and the hamstrings will work. If the feet are too high, the knee can go below them, which means the quadriceps stop working. I conclude that the lying leg press, with the feet placed correctly, is a good alternative to the squat., potentially not quite as effective but safe and easy to use, making it more suitable for weight-training beginners. The seated leg press with feet low is not as good because it lacks the functional relevance.
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2. Leg press This is a good quadriceps exercise. Wilk's research showed that the quadriceps activity was lower than with the squat, but the knee compressive forces are not quite as high. The leg press is also safe from a technique viewpoint as the machine is easy to use. Thus the leg press can be seen as a safer, easy alternative to the squat.
3. Knee extension This is shown by research to be the least effective of the three exercises, as it elicits the lowest quadriceps activity. In addition, because it is an OKC single-joint movement, it has no functional relevance for most athletic movements. The advantage of the knee extension is that compression forces are lower than with the CKC exercises. And, although the knee extension places a strain on the ACL, the level of strain is safe for a healthy knee. The knee extension is therefore a safe quadriceps exercise for athletes without ACL problems, but the fact that it works the quadriceps in isolation makes it much less effective than other exercises. If variation in strength exercises is required, then dumbbell lunges, barbell step ups, and singleleg squats are much better choices since they are CKC multi-joint movements. The only athletic movement the knee extension is functional for is kicking, which requires a powerful isolated quadriceps contraction.
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SOCCER ARTICALS I conclude that the knee extension exercise is the least effective and least functional of the three. However, it is safe (for non-ACL patients) and would be useful for football and rugby players to improve kicking power. Raphael Brandon Useful Links common knee injuries, knee injuries symptoms, runners knee, iliotibial band syndrome (ITBS), knee injuries treatments
aerobic energy system | football
Just to remind you, there are three major systems available for the production of energy in the muscles: the ATP-PC system for high-intensity short bursts; the anaerobic glycolysis system for intermediate bursts of relatively high intensity (this system produces the by-products of lactate ions and hydrogen ions, commonly known as lactic acid); and finally, there is the aerobic system for long efforts of low to moderate intensity. With sporting events such as cycling, swimming and running, where the intensity is constant for the duration of the event, it is possible to estimate the relative contribution of each energy system. For example, the energy for the 100m sprint is split 50 per cent from the ATP-PC system and 50 per cent from the anaerobic glycolysis sytem, whereas the marathon relies entirely on the aerobic system (Newsholme et al, 1992). By contrast, games such as football are characterized by variations in intensity. Short sprints are interspersed with periods of jogging, walking, moderate-paced running and standing still. This kind of activity has been termed 'maximal intermittent exercise'.
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Football: What are the energy demands in this "maximal intermittent exercise"?
It would seem reasonable to assume that during a football game all three energy systems would be required, as intensity varies from low to very high. However, because it is not obvious just how fast, how many and how long the sprints are, and just how easy and how long the intervening periods are, it is difficult to determine which of the energy systems are most important. Thus most of the football-related research has attempted to tackle this problem. A 15m sprint every 90 seconds English researchers Reilly and Thomas (1976) investigated the patterns of football play in the old first division. They found that a player would change activity every 5-6 secs, and on average he would sprint for 15m every 90 seconds. They found the total distance covered varied from 8 to 11 km for an outfield player - 25 per cent of the distance was covered walking, 37 per cent jogging, 20 per cent running below top speed, 11 per cent sprinting and 7 per cent running backwards. Ohashi and colleagues, researching football in Japan, confirmed these findings, showing 70 per cent of the
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The pattern of football play has also been expressed in terms of time. Hungarian researcher Peter Apor and the Japanese researchers both describe football as comprising sprints of 3-5 secs interspersed with rest periods of jogging and walking of 30-90 secs. Therefore, the high to low intensity activity ratio is between 1:10 to 1:20 with respect to time. The aerobic system will be contributing most when the players' activity is low to moderate, ie, when they are walking, jogging and running below maximum. Conversely, the ATP-PC and anaerobic glycolysis systems will contribute during high-intensity periods. These two systems can create energy at a high rate and so are used when intensity is high. The above research has described the average patterns of play during football and from this we can reasonably deduce when each of the energy systems is contributing most. However, now we need to establish just how important each energy system is for footballing success. Recovering from high-intensity bursts There is evidence that the aerobic system is extremely important for football. Along with the fact that players can cover over 10 km in a match, Reilly found heart rate to average 157 bpm. This is the equivalent of operating at 75 per cent of your VO2max for 90 minutes, showing that aerobic contributions are significant. This is confirmed by the fact that various studies have shown footballers to have VO2max scores of 55-65 ml/kg/min. These VO2max scores represent moderately high aerobic power. Reilly and Thomas (1976) showed that there was a high correlation between a player's VO2max and the distance covered in a game. This was supported by Smaros (1980) who also showed that VO2max correlated highly with the number of sprints attempted in a game. These two findings show that a high level of aerobic fitness is very beneficial to a footballer.
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distance was covered at low to moderate pace below 4 m/s, with the remaining 30 per cent covered by running or sprinting at above 4 m/s. Thus, for example, if a football player covers 10 km in total, around 3 km will be done at fast pace, of which probably around 1 km will be done at top speed.
The greater the player's aerobic power the quicker he can recover from the highintensity bursts. These short bursts will be fuelled by the ATP-PC and anaerobic glycolysis systems. Then, during rest periods, a large blood flow is required to replace the used-up phosphate and oxygen stores in the muscles and to help remove any lactate and hydrogen ion by-products. The quicker this is achieved, the sooner a player can repeat the high-intensity sprints, and thus cover more distance and be able to attempt more sprints. So the aerobic system is crucial for fuelling the low to moderate activities during the game, and as a means of recovery between highintensity bursts. Which system fuels the sprints? As already mentioned, the ATP-PC and anaerobic glycolysis systems fuel the highintensity periods. However, if we are to optimize training programmes, we need to know whether in performing the high-intensity bursts both systems contribute evenly or whether one is more important. As the sprints a player makes are mostly 10-25m in length, or 3-5 secs in duration,
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some researchers have assumed that the ATP-PC system will be the most important. However, since football has an intermittent intensity pattern, just because the sprints are brief does not mean that anaerobic glycolysis does not occur; research has shown that anaerobic glycolysis will begin within 3 seconds. To determine whether anaerobic glycolysis is significant during football, researchers have analysed blood lactates during matchplay. However, results from these studies have varied. Tumilty and colleagues from Australia cite research varying from 2 mmol/l, which is a low lactate score indicating little anaerobic glycolysis, to 12 mmol/l, which is quite a high score. Most studies seem to find values in the 4-8 mmol/l range, which suggests that anaerobic glycolysis has a role. The contrast in results is probably due to the varying levels of football in the different studies. Some use college-level players, others professionals. Some studies test training games, others competitive matches. This is likely to confound results. Ekblom, a researcher from Sweden, clearly showed that the level of play was crucial to the lactate levels found. Division One players showed lactate levels of 8-10 mmol/l progressively down to Division Four players showing only 4 mmol/l. Tumilty and colleagues conclude that the contribution of anaerobic glycolysis remains unclear, but is probably significant. They suggest that the tempo of the game may be crucial to whether anaerobic glycolysis is significant or not. As Ekblom noted: 'It seems that the main difference between players of different quality is not the distance covered during the game but the percentage of overall fast-speed distance during the game and the absolute values of maximal speed play during the game'. The conclusion from these lactate studies is that, as the playing standard increases, so may the contribution of anaerobic glycolysis. However, I think more precise research is needed to determine exactly how fast and how frequent the high-intensity efforts during play are. Maximum-intensity bursts with long recoveries will emphasis the ATPPC system, whereas high-intensity but not maximal bursts occurring more frequently will emphasise the anaerobic glycolysis system more. Thus, along with the standard, the style of play and football culture may also influence the physiological demands. This means that the country in which the researchers are based may affect the conclusions they draw when studying the relative contributions of the two systems.
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SOCCER ARTICALS
What action to take From the research completed so far, it would probably be fair to conclude that for the high-intensity bursts during play both the anaerobic glycolysis and the ATP-PC systems contribute, but that the ATP-PC system is more important. This is because the ratio of high-intensity to low-intensity activity is between 1:10 and 1:20 by time. The highintensity periods are very short and the rest periods relatively long. Therefore, the ATP-PC system will probably be more useful and also has sufficient time to recover. Research has also shown that lactate values become moderately high but not so high as to indicate that the anaerobic glycolysis system is working extremely hard. Indirectly, this is confirmed by Smaros who showed that glycogen depletion was mostly in the slow-twitch muscle fibres, which suggests that glycogen is being used for the aerobic system but not the anaerobic system. However, the possibility exists that for professional-standard football, or football played at a high tempo, anaerobic glycolysis will be at least as significant as ATP-PC. If coaches of professional teams want to know better which system is more important, then more research taking place in their own country and using top players as subjects
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A specific type of interval training for footballers would be to mimic the demands of an actual game with the correct work-to-rest ratios and distances covered. If players sprint for over 1 km during a game with high to low ratios of 3-5 secs to 30-90 secs, then a session such as two sets of 20 x 25m maximal sprints with 30 secs rest (2 mins between sets), would represent the demands of a tough match, namely, frequently repeatable high power. To focus solely on the ATP-PC system, short maximal sprints of 20-60m with 1-2 mins recovery are best. To train the anaerobic glycolysis system, longer sprints of 15-30 secs, with 45-90 secs recovery, are recommended. Aerobic training involves running continuously, fartleks, long repetitions (eg, 6 x 800m, 1 min rest) or extensive intervals at moderate speeds (eg, 30 x 200m, 30 secs rest). Trainers should be aware that running sessions, intervals and shuttle runs (or doggies) should be carefully planned so that they target the correct energy system. Running speeds, distances and rest periods should be calculated so that the session will target the specific energy system the coach wants to develop. Raphael Brandon
soccer exercise | aerobic system
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is needed, accurately analysing intensity patterns in matchplay and measuring lactate levels. Until then, training regimes must cater for all three systems, with particular attention to the aerobic and ATP-PC systems. Japanese researchers performed a Maximal Intermittent Exercise (MIE) test on footballers which consisted of 20 x 5 secs maximum efforts with 30 secs active rest. This was meant to mimic a high-intensity section of the game. They correlated the performance on this test with fitness tests representing the three energy systems, VO2max for the aerobic system, lactic power for the anaerobic glycolysis system, and maximum power for the ATP-PC system. All three components of fitness were significant to the performance on the MIE test. Peter Apor agrees with this in making fitness recommendations for footballers, saying that a good aerobic fitness needs to be linked to a moderate anaerobic glycolysis power and a high ATP-PC power.
Soccer exercise energy demands Just to remind you, there are three major systems available for the production of energy in the muscles: the ATP-PC system for high-intensity short bursts; the anaerobic glycolysis system for intermediate bursts of quite high intensity (this system produces the by-products of lactate ions and hydrogen ions, commonly known as lactic acid); and finally, there is the aerobic system for long efforts of low to moderate intensity. With sporting events such as cycling, swimming and running, where the intensity is constant for the duration of the event, it is possible to estimate the relative contribution of each energy system. For example, the energy for the 100m sprint is split 50 per cent from the ATP-PC system and 50 per cent from the anaerobic glycolysis sytem, whereas the marathon relies entirely on the aerobic system (Newsholme et al, 1992). In contrast, games such as soccer are characterized by variations in intensity. Short sprints are interspersed with periods of jogging, walking, moderate-paced running and standing still. This kind of activity has been termed
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SOCCER ARTICALS 'maximal intermittent exercise'.
A 15m sprint every 90 seconds English researchers Reilly and Thomas (1976) investigated the patterns of soccer play in the old first division. They discovered that a player would change activity every 5-6 secs, and on average he would sprint for 15m every 90 seconds. They found the total distance covered varied from 8 to 11 km for an outfield player - 25 per cent of the distance was covered walking, 37 per cent jogging, 20 per cent running below top speed, 11 per cent sprinting and 7 per cent running backwards. Ohashi and colleagues, researching soccer in Japan, confirmed these findings, showing 70 per cent of the distance was covered at low to moderate pace below 4 m/s, with the remaining 30 per cent covered by running or sprinting at above 4 m/s. Thus, for example, if a soccer player covers 10 km in total, around 3 km will be done at fast pace, of which probably around 1 km will be done at top speed. The pattern of soccer play has also been expressed in terms of time. Hungarian researcher Peter Apor and the Japanese researchers both describe soccer as comprising sprints of 3-5 secs interspersed with rest periods of jogging and walking of 30-90 secs. So, the high to low intensity activity ratio is between 1:10 to 1:20 with respect to time. The aerobic system will be contributing most when the players' activity is low to moderate, ie, when they are walking, jogging and running below maximum. Conversely, the ATP-PC and anaerobic glycolysis systems will contribute during high-intensity periods. These two systems can create energy at a high rate and so are used when intensity is high.
SOCCER ARTICALS | FOOT BALL
It would seem reasonable to assume that during a soccer game all three energy systems would be used, as intensity varies from low to very high. However, because it is not obvious just how fast, how many and how long the sprints are, and just how easy and how long the intervening periods are, it is difficult to determine which of the energy systems are most important. Thus most of the soccer-related research has attempted to tackle this problem.
The above research has described the average patterns of play during soccer and from this we can calculate when each of the energy systems is contributing most. However, now we need to establish just how important each energy system is for soccer success. Recovering from high-intensity bursts There is evidence that the aerobic system is very important for soccer. Along with the fact that players can cover over 10 km in a match, Reilly found heart rate to average 157 bpm. This is the equivalent of operating at 75 per cent of your VO2max for 90 minutes, showing that aerobic contributions are significant. This is confirmed by the fact that various studies have shown soccer players to have VO2max scores of 55-65 ml/kg/min. These VO2max scores represent moderately high aerobic power. Reilly and Thomas (1976) showed that there was a high correlation between a player's VO2max and the distance covered in a game. This was supported by Smaros (1980) who also showed that VO2max correlated highly with the number of sprints attempted in a game. These two findings show that a high level of aerobic fitness is very beneficial to a soccer player.
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SOCCER ARTICALS The greater the player's aerobic power the quicker he can recover from the highintensity bursts. These short bursts will be fuelled by the ATP-PC and anaerobic glycolysis systems. Then, during rest periods, a large blood flow is required to replace the used-up phosphate and oxygen stores in the muscles and to help remove any lactate and hydrogen ion by-products. The faster this is achieved, the sooner a player can repeat the high-intensity sprints, and thus cover more distance and be able to attempt more sprints. So the aerobic system is crucial for fuelling the low to moderate activities during the game, and as a means of recovery between high-intensity bursts.
As the sprints a player makes are mostly 10-25m in length, or 3-5 secs in duration, some researchers have assumed that the ATP-PC system will be the most important. But since soccer has an intermittent intensity pattern, just because the sprints are brief does not mean that anaerobic glycolysis does not occur; research has shown that anaerobic glycolysis will begin within 3 seconds. To determine whether anaerobic glycolysis is significant during soccer, researchers have analysed blood lactates during matchplay. But results from these studies have varied. Tumilty and colleagues from Australia cite research varying from 2 mmol/l, which is a low lactate score indicating little anaerobic glycolysis, to 12 mmol/l, which is quite a high score. Most studies seem to find values in the 4-8 mmol/l range, which suggests that anaerobic glycolysis has a role. The contrast in results is probably due to the varying levels of soccer in the different studies. Some use college-level players, others professionals. Some studies test training games, others competitive matches. This is likely to confound results. Ekblom, a researcher from Sweden, clearly showed that the level of play was crucial to the lactate levels found. Division One players showed lactate levels of 8-10 mmol/l progressively down to Division Four players showing only 4 mmol/l. Tumilty and colleagues conclude that the contribution of anaerobic glycolysis remains unclear, but is probably significant. They suggest that the tempo of the game may be vital to whether anaerobic glycolysis is significant or not. As Ekblom noted: 'It seems that the main difference between players of different quality is not the distance covered during the game but the percentage of overall fast-speed distance during the game and the absolute values of maximal speed play during the game'. The conclusion from these lactate studies is that, as the playing standard increases, so might the contribution of anaerobic glycolysis. However, I think more precise research is needed to determine exactly how fast and how frequent the high-intensity efforts during play are. Maximum-intensity bursts with long recoveries will emphasis the ATPPC system, whereas high-intensity but not maximal bursts occurring more frequently will emphasise the anaerobic glycolysis system more. Thus, along with the standard, the style of play and soccer culture may also influence the physiological demands. This means that the country in which the researchers are based may affect the conclusions they draw when studying the relative contributions of the two systems.
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Which system fuels the sprints? As already mentioned, the ATP-PC and anaerobic glycolysis systems fuel the highintensity periods. But if we are to optimize training programmes, we need to know whether in performing the high-intensity bursts both systems contribute evenly or whether one is more important.
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Football coaching: Ball kicking Football coaching: a new measure of kicking accuracy
Frustrated by the limitations of existing methods for assessing kicking accuracy – clearly a vital component of soccer performance – a research team from Minnesota in the US set out to develop and test a sensitive, reliable and valid means of measuring kicking accuracy that was relatively inexpensive, simple to make and easy to use. The result of their endeavours was a plywood target 243.5cm wide and 122cm high, held in an upright position from behind by a wood plank frame. The surface of the plywood was covered with a textured white paint, while a black mark measuring 5cm squared (the bull’s-eye) was placed at the midpoint of the base of the board. A screw was placed in the middle of the bull’s-eye in such a way that a hook at the end of a tape measure could fit over the head of the screw with a view to precisely measuring the distance from the bull’s-eye to the centre of the mark left where the ball struck the target.
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How should a soccer coach measure the kicking accuracy of his forwards and strikers? Number of shots on goal? Okay, but that favours players in positions that shoot more frequently. Number of goals per game? That can be influenced by all sorts of other factors, including skill of the opposing goalie and the defence in general, conditions of the pitch and (of course) the weather. Ability to strike a specified target? Better, but still relatively insensitive as a measure because it doesn’t factor in the magnitude of error when the target is missed, or even which area of the target is struck.
Sheets of white paper covered by carbon paper were placed over the board, such that when the soccer ball struck it left a mark on the underlying white paper. For each new kick a new sheet of paper-plus-carbon was used. To test the accuracy of the system, 10 ball marks were created on the target by having a subject kick a football at it 10 times from a distance of 6.1m. Two ‘raters’ then independently measured the distance from the bull’s-eye to the centre of each ball mark, each taking the marks in a different random order. They then repeated their measurement on the same day, taking the marks in a different random order. Analysis of the results showed a high degree of inter- and intra-rater reliability in measurement, with distances from the bull’s-eye to the ball mark (ranging from 25.7cm to 150.75cm) accurate to within 0.15cm. ‘These results suggest that our method for assessing kicking accuracy is a useful, valid and reliable tool for analysing performance in soccer players,’ state the researchers. ‘To our knowledge, no other tool has demonstrated reliability…Measurements were made to within 0.15cm, suggesting that the target is sensitive to change in kicking
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SOCCER ARTICALS accuracy. Such targets may also be useful in sports other than soccer, such as lacrosse, ice hockey, field hockey and …handball.’ This particular device was tested indoors in a gym. But the researchers point out that game situations could be simulated more accurately by using defenders or a goalie against the player kicking at the target, placing it on a playing field – although not in rain or extreme wind – and/or making it larger to replicate the size of an actual goal (244x732.5cm).
Journal of Science and Medicine in Sport 5(4):348-353 Isabel Walker
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Training and research are the two main applications of the target, they conclude. The bull’s-eye could be moved to different places on the target, allowing players to practise kicking to specific spots. Each player’s accuracy could be determined for each spot, and regions to which the player does not kick accurately could become a primary focus of training. The target could then be used to measure improvements in accuracy over time.
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Genetics Stereotypes about Ethiopian distance runners being born to win are well known, but is athletic prowess really based on genetic traits? Can a super athlete parent guarantee the same in a child? Were the Finnish born to consistently medal in the javelin throw? Read on to find out answers to these and more… To browse our library of free sports training articles, browse using the categories on the left or use the search box
Metabolic rate basically refers to the energy that is released by the body. Sports training can have a significant effect on metabolic rate – this can determine weight gain and weight loss. This is because it boosts calorie burning. This is a result of 1) doing the activity itself 2) the effects of a process known as ‘excess post oxygen consumption’ (EPOC) – of which more later – and 3) by creating a body whose constituent parts (specifically muscle) create an all day and every day increased calorie requirement (again of which more later).
Metabolic rate is comprised of: Total Daily Energy Expenditure (TDEE) This refers to all the energy we expend over a day Resting Metabolic Rate (RMR) 60-75% of TDEE is used to maintain RMR. RMR includes all those ‘behind the scenes’ essential bodily functions, such as heart, lung and mental function, but does not account for calories burned when sleeping Thermic Effect of Feeding (TEF) Food provides us with energy, but the process of eating also requires energy. Around 10% of or TDEE is made up of this requirement Activity This may be a surprise but only 10-15% of our total daily energy expenditure comes from physical activity of any sort. However, this relatively small amount can have a huge effect on our body composition, i.e. how much fat we have and how many calories we need to optimally sustain ourselves and our sports/fitness training
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Metabolic rate: sports training has a significant effect on weight gain and weight loss The effects sports and fitness training has on our metabolic rate and calorific needs
How do you know how many calories you are burning during exercise? When we exercise we increase our metabolic rate as our body boosts its energy output to meet demand. Calories measure the energy release from food (see box). Research has provided the calorific requirements of numerous sports activities. It should be noted that although these figures are relatively accurate, they vary in regard to: Your weight. A heavier person will burn more calories, everything else being equal compared to a lighter one, simply because more energy is required to overcome the greater resistance.
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How to calculate metabolic rateFollowing the steps below will enable you to gain an indication of the calorific value of your metabolic rate Step 1 Calculate your RMR Age:
18-30 Multiply your weight in Kg x 14.7 and add 496 Example: 65Kg Individual 65 x 14.7 + 496 = 1451.5 RMR
31-60 Multiply your weight in Kg x 8.7 and add 829 65 Kg Individual 65 x 8.7 + 829 = 1394.5 RMR
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Your level of fitness. Someone who is fitter, for example, at rowing will be more ‘energy (and therefore calorie) efficient’ than someone who is less fit. This is why exercise intensity needs to be continually increased (progressively) if increased calorie burning is your objective, for example, in order to achieve a weight loss goal (or negative energy balance – of which more later). Atmospheric conditions. The body will burn more calories in hotter, humid conditions than in temperate ones. This is due to the energy required to maintain its cooling processes and reduce core temperature Body types. Certain people – particularly those with lean wiry frames (‘ectomorphs’) – tend to have faster metabolic rates, which can enhance calorie burning. Metabolic rate generally slows with age, sports and fitness training can do much to challenge this. Table 1 displays the calories burned during various sport and fitness activities. It will be of use to athlete and coach in terms of calculating calorific expenditure
Step 2 Estimate your daily activity requirements in calories Multiply your RMR by your daily activity level as indicated by one of the figures in the table below Activity level Not much Moderate Active
Defined as Little or no physical activity RMR x 1.4 Some physical activity, perhaps at work or the odd RMR x 1.7 weekly gym visit Regular physical activity at work and or at the gym RMR x 2.0 (three visits per week)
Examples:25 year old weights 65Kg and has a moderate activity level – 1451.5 x 1.7 = 2466.7 Kcal40 year old weighs 80Kg and has an active activity level – 1525 x 2.0 = 3050 KcalAdapted from
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Bean, A: The Complete Guide to Sports NutritionExcess post oxygen consumption (EPOC) Sports and fitness training can increase metabolic rate by as much as 20%. This is due to EPOC. Unlike a car when the ignition is turned off, our body’s engine does not stop immediately after we have taken it for a run, row or performed a weights workout. The processes involved in producing the energy required for these and all other sports, fitness and general activity, take a while to slow down and return to base line levels. These processes include, the restocking of muscle fuel (notably a specific type of carbohydrate, known as glycogen) and the normalisation of lactate levels in our body. Lactate is used in energy creation at all times. Its levels increase with exercise. When we stop exercising it is still buzzing around inside us at a great rate. It needs time to slow down and in some circumstances be re-converted back to its original chemical format – and this all requires energy. Additionally, when we workout, particularly using weights, microscopic tears occur in our muscles and it is during the recovery period when these are repaired and our muscles grow stronger – again this requires energy. The more the intense the exercise the greater the EPOC.Sports scientists have discovered two distinct EPOC phases:EPOC phase 1The most significant – in terms of calorie burning – occurs in the two to three hours after training. The less significant given the same criteria lasts up to 48 hours after training.If you do not factor EPOC in to your calorie requirements you could experience muscle loss, lack of energy and a failure to obtain sufficient amounts of vitamins and minerals needed to optimally maintain bodily processes. Basically your body would be running ‘energy light’ – not getting enough fuel to optimally power it.Table 1 Energy expenditure and exerciseEnergy expenditure in calories per minute for selected activities against selected body weight (Kg) Activity
Kg 59
62
65
68
71
74
77
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3.3 6.5
3.4 6.8
3.6 7.1
3.7 7.4
3.9 7.7
4.0 8.0
6.4 6.8 7.6 7.9
7.1 8.3
7.4 8.7
7.7 9.1
8.1 9.5
8.4 9.9
8.7 10.2
12.5 13.1 13.6 14.2 14.8 15.4 16.0 16.5
Weight and plyometric (jumping) training burn approximately 5-8 calories per minute dependent on body weight and exercise intensityHow can you specifically measure the amount of calories you burn during a workout?As well as using the figures from table 1 (and other similar calculators that you can find on the net), you can use:Calorie counters on heart rate monitors. However, they only provide an estimate of energy expenditure and are about 90% accurate.Galvanic response. The 100% accurate method is to use devices that measure what’s known as galvanic skin response (basically electrical energy) produced by the body. These are worn usually on the upper arm and the information from them is downloaded. These devices are becoming increasingly available in the fitness and sports world – they were originally the preserve of cardiologists in the medical world.As a sports or fitness participant you must factor in EPOC when calculating your calorie expenditure and metabolic needs, for the reasons mentioned, if you are to optimise your training. Muscle as a calorie burnerIt was mentioned that increased lean muscle mass can increase metabolic requirements. Muscle is very active body tissue, not only when it is firing to produce sports and fitness movements, but also when it is ‘sitting’ on your body. Research indicates that an additional 0.45Kg (1lb) of muscle burns about 35 calories a day. Now that does not sound a lot, but over 10 days that 0.45kg will have amounted to 350 calories, which is the
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Volleyball Easy cycling Tennis Easy swimming Running 8 min/mile pace
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equivalent of a half hour moderately paced run. So as with EPOC it is important to account for the effects that an increase in lean muscle can have on metabolic rate. Note: women may not benefit to the same extent as men from increased lean muscle mass calorie burning. This may reflect their naturally higher levels of body fat – with the latter cancelling out the gains made by the former Understanding food energy A Kilocalorie (Kcal) represents the amount of energy needed to increase the temperature of 1Kg of water by 1 degree centigrade and is the unit commonly used to measure the energy released from food or burned in sports activities. As in this article, Kilocalories are often referred to simply as ‘calories’. Food packaging also gives energy release in kilojoules (kJ), the international standard for energy. To convert Kcal to kJ, multiply by 4.2 and to convert kJ to Kcal divide by 4.2. The energy balance equationIn order to lose weight you need to create a ‘negative energy balance’ – that is, to consume fewer calories than you expend. In order to gain weight (and this could be your objective, if you want to increase muscle mass for a sport such as shot-putting), you need a ‘positive energy balance’ – that is, to consume more calories than you expend. And to maintain weight you need to create a ‘balanced energy balance’ – to consume a similar amount of calories to those expended.As you’ll have realised, metabolic rate is a very important variable in terms of maintaining optimum physical condition and weight. As an athlete or fitness trainer, fully comprehending what effects your training routine is having on it will enable you to optimise your training returns. Failure to do so could result in impaired training response, illness and injury, due to insufficient calories and the optimum supply of nutrients required to maximise physical performance. Body type training – are we slaves to our ‘body type’ genes?
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Body type training – are we slaves to our ‘body type’ genes?
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Article at a glance: The classification of body types is made; The relationship between body types, sports suitability and sports performance is identified; Other factors influencing sports performance from a physiological perspective are presented. The human body comes in a huge array of different shapes and sizes, but should your natural body type dictate the sport you choose or the way you train? John Shepherd looks at the evidence and in particular whether it’s nature or nurture that really countsIn a particular sport or event within a sport, the participants will often share a similar body shape. For example, male sprinters tend to be relatively tall and be proportionately muscled, whilst female gymnasts tend to be relatively slight with very low body fat and shot-putters relatively round with more body fat and large muscles. These sports’ body shapes quite closely reflect the three derivative ‘somatotypes’ (body type classifications). The sprinter fits the typical mesomorph body type, the gymnast the ectomorph, and the shot-putter the endomorph. In this article, we’ll consider the relationship between body types, sports performance and training response. Somatotypes, body classification and ‘typical’ training responseAs indicated there are three main body types or somatotypes: endomorphs, mesomorphs and ectomorphs. This basic classification derives from the work of the psychologist William Sheldon in the mid 20th century. In everyday terms these types can be described as ‘fat’, ‘athletic’ and ‘thin’ (see figure 1). Sheldon believed that each somatotype had distinct physiological (and psychological) traits. Figure 1: Sheldon’s three main somatotypes
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Although his work is perhaps overstated it provides a useful starting point for the analysis of male and female body types. This is because it’s possible to identify the ways that these types will typically respond physiologically to training and the way they are represented across various sports.Most athletes (and non-athletes) are actually an amalgamation of the three main body types and there is a further level of somatotype classification that describes a body type in terms of ‘parts’ of the three. This is known as ‘dominant somatotype’. Sheldon identified ‘seven parts’, 1-7 for each somatotype, with 1 being the minimum and 7 the maximum number of parts attributable to that somatotype. For example, 2-6-3 indicates low endomorphy, high mesomorphy and low ectomorphy (note variations to this system exist which use decimal points). The panels on this page describe the three main body types more fully. The influence of body type on sports selection Athletes often seem to fit a blueprint for their sport and numerous research findings appear to confirm what common sense suggests. Greek researchers looked at the somatotypes (as well as body composition and anthropometric measurements) of 518 elite Greek basketball, volleyball and handball players(1). The team
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discovered that the volleyball players were the tallest and had the lowest levels of body fat. Their somatotype was characterised as ‘balanced endomorph’ (3.4-2.7-2.9). Basketball players were taller and leaner than handball players. The former were profiled as mesomorph-endomorph (3.7-2.7-2.9). The latter were profiled as mesomorph-endomorph also but their ratio was identified as 4.24.7-1.8. Jargonbuster Body composition The ratio of lean (muscle) mass to fat (non lean weight) Anthropometric measurements Specific measurements of limbs and body parts Overtraining syndrome Identified state of health when the athlete will negatively adapt to training, become injured or ill Delving deeper, the researchers also considered level of performance, as the athletes represented both the first and second divisions of their sports. Interestingly it was discovered that the first division players were taller, heavier, but leaner than the second division players. Even more interesting was the fact that players from all the three sports displayed a greater similarity between somatotype characteristics. It is possible that this similarity could be attributed to that particular somatotype balance making for ‘better’ players. American researchers went a little further than their Greek counterparts by looking at somatotype differences within a sport(2). Specifically, they considered 168 elite basketball players. The team discovered that there were considerable differences between playing positions; guards had greater mesomorphy than centres, and less ectomorphy than forwards and centres. Serbian researchers took up the theme of this research and basketball was again the sport of choice(3). Interestingly the conclusions on somatotypes by the Greek researchers were somewhat different than those reached by their Serbian
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counterparts (of which more later). The particularly interesting aspect of this research was the inclusion of the relationship between physiological capability and body type across a number of measures. The 60 players surveyed came from five clubs in the Serbian first division. Physiological testing of the players was carried out during the final week of their pre-season training. Players were categorised according to court position. Here’s what the researchers found: Centres were taller and heavier than guards and forwards; Forwards were taller and heavier than guards; Centres carried more body fat than guards and forwards; Centres had lower estimated VO2max values compared to forwards and guards; Guards’ heart rates did not reach the same levels of centres and forwards during the last minute of a bleep test; Centres had better vertical jump power than guards. These findings led the researchers to conclude that ‘The results of the present study demonstrate that a strong relationship exists between body composition, aerobic fitness, anaerobic power and positional roles in elite basketball.’ Conundrum You may have noticed that the Greeks and Serbian researchers were not consistent in their findings relating to body type propensities and basketball playing position. The Greek guards for example had greater mesomorphy (and endomorphic tendencies) than their Serbian counterparts; however, it was the Serbian centres who were more mesomorphic with endomorphic tendencies. This throws up a very interesting conundrum and challenges the assumption that only certain classifications of body types are suitable for certain sports/positions. Although it is a given that being tall will be a distinct advantage for basketball, it may well also be that training factors or even the natural genetic tendencies of a race can also influence the ‘ideal playing position shape’. This
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also chimes in with recent research identifying the presence of certain ‘sporting genes’ – ie genes that are a positive asset for sports performance (more on this later). Nature versus nurture and the identification of sporting genes Body type is established at birth, while body shape is the result of physiological adaptations to training, diet and lifestyle factors. However, there are sufficient anomalies in sport to show that body types can vary (to a degree) within a sport and player positions. Compare for example the more endomorphic-mesomorph body shape of English striker Wayne Rooney with the more ectomorphic-mesomorph French striker Thierry Henri – both great footballers. According to Mike Rennie, professor of clinical physiology at the University of Nottingham Medical School in Derby, the split between nature and nurture is about 55:45. He provides the example of identical twins from Germany, one of whom was an endurance athlete, the other a power sportsman(4). Nurture is of course a powerful influencing factor and one that is often cited in the case of Kenyan distance runners who have won more distance, steeplechase and cross-country Olympic and world titles than any other nationality. However, the famed running doctor Tim Noakes indicates that these runners have a greater preponderance of fast-twitch muscle fibre, especially when compared to their North American and European counterparts(5). But it is also possible to argue that this is a training response and not a genetic one as most humans start off with a fairly even distribution of fast- and slow-twitch muscle fibres. And perhaps even more crucially for the nurture argument, running is an endemic feature of Kenyan life. It’s also one of the few areas where Kenyans can display their prominence on the world stage and gain individual notoriety and wealth; this makes it all the more likely for them to do it. Jargonbuster Fast-twitch muscle fibre
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Power and speed producing muscle fibre Slow-twitch muscle fibre Endurance producing muscle fibre Sporting genes Research has recently begun to appear on sporting genes. These are specific identifiable genes that have been found to be relevant to enhanced sports performance. By 2005 nearly 200 genes had already been identified as having a direct effect on sports and fitness performance and training adaptation(6). The EPOR (erythropoietin receptor) gene, for example, has been identified as crucial for red blood cell production. In some people this gene mutates and continues to work producing an abnormal amount of red blood cells. Finnish researchers identified an entire family with this EPOR mutation, several of whom were championship endurance athletes, including the great cross-country gold medalist skier, Eero Mantyranta(4). Mantyranta won two gold medals at the 1964 winter games and it was discovered that EPOR mutation allowed him to produce 50% more red blood cells(7). As red blood cells are crucial for carrying oxygen to the working muscle the EPOR gene is crucial for enhancing aerobic performance, regardless of body type. Other similar genetic research has indicated that one in five Europeans cannot produce the alpha-actinin-3 protein found in fast-twitch muscle fibres. This genotype is crucial for speed and power sports(4). A lack of it appears to reduce the potential for Europeans to be as fast as their Afro-American counterparts. Coincidentally it is being argued that the first genetically mutated athletes could be competing in next year’s Olympic games! The difference between body type and body shape Body shape is the trained response or the everyday life response/effect that ‘changes’ an individual’s body type. Long distance runners may have a body type that has mesomorphic tendencies; however, while they are in training, due to their high calorie expenditure and lack of training emphasis on building (and
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maintaining muscle) they may well develop a more ectomorphic shape. At the other end of the spectrum, countless millions of the sedentary general public will gradually take on more of an endomorphic shape as they gain weight, due to a lack of exercise, excess calorie intake and poor food choices generally! Conclusions Body type analyses provide a strong starting point for sports selection, prowess and training response. Although it is very much the case that certain body types seem better suited to certain sports, there is still very much a degree of ‘you are what you train for’. This is true within certain parameters and has been exemplified by research pointing to differences and anomalies within playing position in basketball (and other sports). Additionally, the more recent research into sporting genes could have even greater implications than body type in terms of ‘determining’ who will be good at certain sports and indeed who will be ‘made’ better at sport. John Shepherd MA is a specialist health, sport and fitness writer and a former international long jumper References Sports Med Phys Fitness 2006 Jun; 46(2):271-80 J Sports Sci 2005 Oct; 23(10):1057-63 J Strength Cond Res 2006 Nov; 20(4):740-4 The Guardian, Thursday August 5, 2004 The Lore of Running, Noakes T www.medscape.com/viewarticle/551096 www.newscientist.com/channel/life/ genetics/mg19125655.300only-drugs-can-stop-the-sports-cheats.html
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women faster than men Woman Faster Than Men? : Will women ever outpace men? That is a question that has obsessed many commentators in the sports science community for a number of years – and the answer is less clear-cut than it used to be. The authors of a leading article 137
published in the prestigious British Journal of Sports Medicine point out that: ‘Although serious consideration does not indicate the slightest chance of a woman being the fastest human on the planet at distances of 100-200m, there are factors that may favour women over longer distances’. It is not only the rapid improvement in female running, especially over the marathon distance, between 1963 and 1984 that supports this idea, they explain. Further backing comes from scientific evidence of natural female advantages, including the ability to run aerobically at a higher percentage of maximal oxygen uptake, resistance to oxidative stress and a higher pain threshold. And, although men show no signs as yet of being beaten over Olympic distances, they are already beginning to lose the battle at ultra-distances. As the leader points out, consistent male superiority is already a matter of history in possibly the most challenging ultra-race, the ‘Badwater Ultramarathon’, a 216k race at crucifying temperatures of up to 55°C. Although men dominated this race during the 1980s and 1990s, in 2002 and 2003 a female ultra-runner outpaced the fastest man by about 4.5 and 0.5 hours respectively. Furthermore, since 2002 up to three women have been in the first five finishers, even through there were more male than female participants. Pundits will be watching with intense interest to see whether this apparent advantage can be transferred to shorter races. Br J Sports Med 2005; 39:410 gender performance Gender Performance : Will women ever outpace men?
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Will females ever outpace males in running events? Time and again this question has led to fierce debate within the lay and scientific community (1-6). Performance differentials between men and women are most commonly attributed to such issues as body size and composition, with men tending to be larger than women, with a lower percentage of body fat combined with a higher relative muscle mass. From this perspective, there is not the slightest chance of a female being the fastest human on the planet over 100m or 200m, argue Professor Ralph Beneke and Dr Renate Leithäuser.
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SOCCER ARTICALS Men also have a higher aerobic capacity and a bigger absolute and relative mass of haemoglobin than women. But, while these attributes appear to give men an advantage in endurance events, their greater muscle mass can be a disadvantage in such events. Rapid improvements in female marathon performance between 1963 and 1984 (see figure 1, below) served to support the idea that women might one day outpace men in longdistance events (4). However, marathon performances by both sexes are more likely to reflect historical than biological factors.
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Figure 1: graph showing reductions in male and female world-best marathon times from 1908, with projections to 2050. Note that the model implies women will never outpace men in the marathon
Male marathoners demonstrated huge improvements during the early years of the last century, after the current marathon distance was established as an Olympic event. After near- stagnant progress between the 1920s and 50s, a new period of rapid improvement 139
was ushered in by scientific progress in coaching and sports medicine, although the rate of improvement slowed down significantly after the 1970s. The lack of improvement in female marathon performance between 1926 and 1963 can be attributed to the fact that women could not officially participate in marathon races. In fact, in spite of dramatic improvements in female performance during the 1970s, 80s and 90s, it wasn’t until 1984 that the marathon became a female Olympic event. However, men have always been faster than women over every Olympic distance, and a model applied on all world best results over the marathon distance set since 1908 predicts an endpoint of marathon performance in females at two hours, 15 minutes (see figure 1). This prediction may be a rather conservative if not pessimistic view, particularly in the light of the fact that this time was almost reached (by the UK’s Paula Radcliffe) in 2003. However, when applied to males, the model forecasts faster times than previously predicted (1:57:46). Irrespective of whether such a model allows for meaningful extrapolations to the near or far future, it clearly supports the idea of a near- plateau in gender differences at this distance (6,7). Further analyses supported the idea of a steady gender difference of about 10% in races up to 200km (8) . Nevertheless, there are some important factors that may favour women over very long distances. Any form of exercise starts a series of acute physiological reactions involving activation of the hormonal and autonomic nervous system. These responses affect, in turn, the conversion of food to energy and the subjective perception of exercise (9). And there is evidence that these effects are highly gender-specific (10). There is some evidence that women can run aerobically at a higher percentage of their maximal oxygen uptake than men (7). During the early phase of a 90-minute run, women were able to convert more fat to energy than men; and, more importantly, if a
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carbohydrate drink was provided during the run, they were able to convert a greater relative proportion of it to energy than men. The implication of this research is that carbohydrate ingestion, which is particularly common in longer events, is likely to be more effective in conserving the body’s own glycogen stores in women than in men, which would be particularly conducive to success in races longer than the marathon. Other research has shown that women are more resistant than men to the potentially damaging oxidative stress that accompanies endurance exercise (11). This is partly because they have more effective mechanisms for breaking down fats into their constituent fatty acids – a process known as ‘lipolysis’ which acts as a defence against oxidative stress (12). Growth hormone levels increase during acute exercise and are thought to promote positive adaptations to training and recovery. Higher natural levels of growth hormone have been seen in women than in men (13). Whether or not such findings provide meaningful clues to whether or not women will be able to close the performance gap in races up to 200k, consistent male superiority is already a matter of history in possibly the most challenging ultra-race, the Badwater Ultramarathon. This event, starting in California’s notoriously inhospitable Death Valley, is a 216k one-stage race performed at temperatures up to 55°C and bedevilled by challenging uphill and downhill stretches, as illustrated in figure 2 below. Figure 2: elevation profile of the challenging Badwater Ultramarathon
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Males dominated this event during the 1980s and 90s. However, despite the fact that women have less effective mechanisms than men for regulating their body heat in extremely hot environments (14) , in both 2002 and 2003 a female ultra-runner outpaced the fastest male by about 4.5 and 0.5 hours, respectively. Furthermore, in each of the last three years, up to three women have been within the first five finishers – particularly impressive given that this is a race that has always attracted significantly more male than female participants. Will females consistently outpace males over such ultra distances in the future? That may soon be a matter of fact rather than conjecture. Professor Ralph Beneke (BSc, MD, PhD) and Dr Renate Leithäuser (MD, PhD) are both physicians and sports and exercise
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1. Br J Sports Med 39(7):410 2. Nature 431:525, 2004 3. Science 305:639-640, 2004 4. J Appl Physiol 67:453-465, 1989 5. Nature 355:25, 1992 6. J Sports Med Phys Fitness 44(1):8-14, 2004 7. Int J Sport Nutr Exerc Metab 13(4):407-421, 2003 8. Can J Appl Physiol 29:139-145, 2004 9. J Endocrinol Invest 26(9):879-85, 2003 10. Pain 96(3):335-342, 2002 11. Arch Med Res 35(4):294-300, 2004 12. Eur J Appl Physiol 85:151-156, 2001 13. J Endocrinol Invest 27(2):121-129, 2004 14. Sports Med 229(5):329-359, 2000
15. Sports Science Glossary Part 6 16. Sports Science Glossary Part 6 Linear progression The record for an event, plotted against time, falls roughly along a straight line Asymptotic progression The record for an event falls along a curve that flattens out gradually with time Aerobic capacity The ability to process oxygen for conversion to energy Haemoglobin A substance contained in red blood cells that is responsible for transporting oxygen around the body Autonomic nervous system Governs bodily functions that are not under conscious control – eg heartbeat Oxidative stress A series of reactions to increased use of oxygen, including the production of potentially harmful ‘free radicals’
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scientists at the University of Essex. They are both involved in the training of world class athletes References
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East African running East African running: an alternative explanation for the East African dominance of distance running
Researchers have long speculated on the factors that contribute to making an elite athlete. When a particular group appears to dominate a given domain, even more speculation and interest is generated. Current examples from sport include the American dominance of basketball and the Northern European dominance of Nordic skiing. An example that has garnered much attention(1,2) is East African dominance of middle- and long-distance running. Although several empirically based positions have been advanced to explain the interindividual variation in performance(3,4), the dominance of black athletes in certain sports has been commonly attributed to factors such as social Darwinism – that is, the hardships of slavery resulted in a degree of genetic selection(5) – and environmental determinism – that is, physiological adaptations associated with living under certain environmental conditions (1). Hamilton (6) examined empirical evidence for a range of influences that may contribute to East African running dominance, including environmental, social, psychological, and physiological variables. After examining research from various disciplines, he concluded that there was no clear explanation for the East African supremacy. However, Hamilton argued that psychological factors may perpetuate this dominance by attributing differences between African and white running performances to stable external factors, thereby disempowering white runners and empowering East African runners. Regardless of the possible existence of physiological advantages in East African runners, belief that such differences exist creates a psychological atmosphere that can have significant consequences on performance.
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The following original paper from Canada, published recently in the British Journal of Sports Medicine, is reproduced in full by kind permission of the BMJ Publishing Group. Br J Sports Med 2003;37:553-555
Stereotype threat Recent research in psychology has unveiled insights that are particularly relevant to this debate. It is distinctly possible that what we believe to be true about our genetic make-up may be more important than what is actually true. Stone et al(7) gave black and white students a laboratory golf task that ostensibly measured ‘natural athletic ability’, ‘sport intelligence’, or ‘sport psychology’,
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Steele and Aronson(8) introduced stereotype threat as an explanation for the lower scores of black American students on standardised intelligence tests. The authors had been perplexed by the persistent gap in scores between blacks and whites, which endured even if black students came from well educated families of middle-class standing. However, Steele and Aronson found that black students scored just as well as whites on standard intelligence tests when the tests were presented as diagnostic tools that did not measure intellectual capacities. They determined that it was not the test itself, rather the situational pressure surrounding the test, that resulted in poorer scores. Performance decreased when black students were confronted with the possibility of confirming a widespread stereotype about low intelligence in blacks. Significantly, stereotype threat affects the academic vanguard more than it does the weaker students. A person has to care about a domain in order to be disturbed by the prospect of being stereotyped in it. Good students are generally invested in and have identified with the domain and thus are more prone to the situational pressure that is stereotype threat. Students who did not identify with the domain were remarkably unaffected. Weaker students reduced cognitive effort as soon as the test became challenging, resulting in poor performance, regardless of whether they were under stereotype threat or not(9). Therein lies another key to stereotype threat – the test must be challenging. It is only when one gets to a difficult section, and the possibility arises of confirming the negative stereotype, that sufficient stress arises to impair performance.
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depending on how the test was presented. Nothing changed in the test itself, just the perception of what the test measured. Both black and white students scored equally well on the sport psychology control condition. However, black participants outperformed white ones when the task was framed as a test of natural athletic ability, whereas white participants outperformed black ones when the task was framed as a test of sport intelligence. This phenomenon is referred to as stereotype threat and may be of help in explaining the dominance of certain sports by specific groups. Although scientific inquiry into genetic differences between races remains unresolved, previous research suggests that belief in such differences has a large impact on performance.
Oddly enough, a person does not even have to believe the stereotype to be affected by it. Awareness, even at a subconscious level, appears to be sufficient. For example, Levy (10) primed [senior citizens] using subliminal messages and then gave them a memory test. Those who had been primed with negative words associated with old age, such as senile or forgetful, performed worse than seniors primed with positive words like wise and sage. Spencer et al (11) found that stereotype threat was equally applicable to women and maths skills. If women are reminded of the stereotype that they are inferior to men in mathematical ability, their test scores decrease. If the same test is reframed so that women believe it is simply a research tool, they score just as well as men. Current findings indicate that anywhere a stereotype exists, stereotype threat can be invoked and performance depressed. In a related study, white men, selected on the basis of
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SOCCER ARTICALS their strong maths skills, performed worse when they were compared with Asian men, a group traditionally thought to excel at maths. A control group not subjected to stereotype threat suffered no such performance decrease (12).
This widespread societal belief in the athletic superiority of blacks is actually a relatively recent phenomenon. Hoberman (14) notes that during colonial rule blacks were considered inferior sportsmen. In fact, at the dawn of the 20th century there was concern even among black scholars at the lack of physicality of the black race(14). However, the tables have turned considerably in the past hundred years. Impressive accomplishments from black athletes during the first decade of the 1900s – for example, Marshall Taylor and Jack Johnson – followed by the record-breaking performances of black sprinters like Jesse Owens provided the basis for the belief that black athletic superiority is genetic in origin(15). The current dominance of black athletes in a number of high-profile sports has certainly done nothing to dispel this belief. Furthermore, as Hamilton suggests(6), the psychological edge this belief gives black athletes may be the key to maintaining that superiority. Indeed, in stereotype threat we see evidence of the power of such beliefs.
Short-term effects
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The sporting field also contains its share of stereotypes, particularly when it comes to black-white differences. The perception of the athletic superiority of black people is widespread, with the media contributing substantially to such thinking (2,5). Stone et al(13) examined popular perceptions of racial stereotypes by having participants evaluate the abilities of a male basketball player based on a radio broadcast of a college game. Even though participants listened to the same broadcast, they were more likely to attribute talent and natural athletic ability to the player if they thought he was black and were more likely to attribute hard work and sport intelligence to the player if they believed he was white.
The poorer performance associated with stereotype threat has been attributed to the anxiety and distress caused by association with a negative stereotype. Blascovich et al(16) examined the effects of stereotype threat on blood pressure in African Americans. They found that groups placed under stereotype threat displayed larger increases in mean arterial blood pressure (a measure of somatic anxiety) and performed more poorly on difficult test items than African Americans not under stereotype threat. In typical models of anxiety(17), the occurrence of a stressor, in this case stereotype threat, creates a state of anxiety (see figure 1, below). State anxiety(18) is manifested either somatically through physical responses, such as sweating and increased respiration, or cognitively through worry or concentration disruption. Each of these manifestations has been linked to negative effects on physical performance(19). Further, whereas a certain amount of physical arousal has been seen as beneficial for sport performance (cf the inverted U hypothesis)(20), certain research(21) suggests that any amount of cognitive anxiety is detrimental to performance.
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SOCCER ARTICALS Moreover, athletes performing at elite levels of competition normally adopt a telic, or serious, goal-oriented motivational state. To the elite athlete, performing well is an important outcome. However, researchers(22,23) suggest that adopting a motivational state that is telic is more highly affected by anxiety than adopting a paratelic – that is, playful, non-serious – motivational state.
Perhaps the most damaging effects of stereotype threat are long-term, such as feelings of dissatisfaction and ultimately dropout from sport. The benefits of longterm involvement in physical activity are well known. They include increases in physical competence and associated increases in self-esteem(24). However, Steele(25) postulated that, in chronic situations of stereotype threat, individuals become pressured to ‘disidentify’ with the domain to preserve feelings of self-worth. Disidentification involves a reconceptualisation of one’s self-image to remove the value associated with a domain, thereby reducing the impact of negative performance. Stone(26) recently replicated these results in a sport context.
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Long-term effects
Disidentification, although useful for maintaining self-image, can undermine the motivation required for long-term involvement in an activity. Sustained motivation is dependent on feelings of achievement and accomplishment(27). In a related study, Stone(26) found that stereotype threat was related to the quality of practice performed by participants executing a golf task. Specifically, white athletes who felt they were being examined for natural athletic ability showed less practice effort than white athletes who were not under the threat of confirming racially based stereotypes – that is, poor white athleticism. In addition, stereotype threat only affected athletes for whom sport was an important component of their self concept. Participants who were disconnected from the outcome of the task performed at a level no different from control subjects. Stone hypothesised that athletes concerned with confirming a racially based stereotype ‘self-handicap’ – that is, perform less effortful practice – to
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SOCCER ARTICALS create ambiguity about the cause of a poor performance. Athletes proactively respond to an anticipated mediocre outcome by withdrawing practice effort, thereby avoiding the confirmation of a stereotype about poor natural athletic ability in white athletes. Although longitudinal studies of the effects of these actions have not been performed, it seems reasonable that decreased practice effort over time would undermine skill acquisition and limit the physiological adaptations necessary for performance at the highest levels of sport competition.
The extent to which athletes choose or opt out of sports based on perceived genetic suitability is an area worthy of future study. Just as negative stereotypes can lead women away from maths-based careers in finance or engineering, there is evidence to suggest that athletes may be choosing their sports based on athletic stereotypes. Coakley(28) notes that young athletes have internalised these stereotypes and are choosing sport participation accordingly. He speculates that this is the reason why white running times in certain events have actually decreased over the past few years; whites are opting out of some sports based on perceived genetic inferiority. Coaches and support staff need to be aware of ways of dealing with situations involving stereotype threat. Steele(25) presented methods for overcoming stereotype threat in academic settings, several of which are also useful for performance in the athletic environment. Steele(9) theorised that underperformance appeared to be rooted less in self doubt than in social mistrust. Therefore niceness and reassurance on the part of the teachers was not enough. Steele found that emphasising high standards was the key to gaining social trust. For criticism to be accepted across the racial divide in an academic setting, feedback had to be given with the emphasis on high standards, conveyed with the belief that the student could achieve those standards.
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Effects on young athletes
Although this research has yet to be replicated in an athletic domain, it provides clear guidance for coaches working in multiracial environments. When dealing with athletes, coaches should consistently emphasise high standards of performance for all, irrespective of race. Evidence suggests in order for stereotype threat to influence performance, the stereotype must be made salient in the particular context, Accordingly, coaches should avoid off-hand comments or jokes suggesting, for example, ‘white men can’t jump’ or ‘blacks are better runners’, especially before competition. In addition, coaches and trainers should show clear optimism in their athlete’s abilities. All attempts should be made to increase the athlete’s feelings of self-efficacy – that is, the athletes’ beliefs in their abilities to accomplish desired courses of action – before competition. Moreover, these feelings must be reinforced after the event regardless of the results to ensure that stereotype threat has a limited role in future competitions. Clearly, coaches should also stress the equivocal research findings on race and athletic performance. One method of reducing the negative consequences associated with stereotype threat is by minimising the legitimacy of the stereotype. If athletes are educated as to the lack of consistent findings for racial dominance in sport, the power of the stereotype may be effectively limited.
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SOCCER ARTICALS Research examining the role of stereotype threat in elite levels of performance is virtually non-existent. As a result, the suggestions presented in this paper, although based on strong research with non-elite samples, remain speculative. Future research should consider the role of stereotype threat as a reason for performance differences in racially dominated sports such as middle- and long-distance running. Without indisputable evidence indicating the genetic advantages associated with a specific racial group, researchers should continue to examine alternative explanations for the apparent dominance of one group over another in sport. J Baker, S Horton
1. Bale J, Sang J: Kenyan Running: movement culture, geography and global change. London: Frank Cass, 1996 2. Entine J: Taboo: why black athletes dominate sports and why we are afraid to talk about it. New York: Public Affairs, 2000 3. Bouchard C, Malina RM, Perusse L: Genetics of fitness and physical performance. Champaign, IL: Human Kinetics, 1997 4. Psychol Rev 1993;100:363-406 5. Sports Illustrated 1971; 43:72-83 6. Br J Sports Med 2000;34:391-4 7. J Pers Soc Psychol 1999;77:1213-27 8. J Pers Soc Psychol 1995;69:797-811 9. The Atlantic Monthly 1999;284:44-54 10. J Pers Soc Psychol 1996;7:1092-107 11. J Exp Soc Psychol 1999;35:4-28 12. J Exp Soc Psychol;35:29-46 13. Basic Appl Soc Psychol 1997;19:291-306 14. Hoberman J: Darwin’s athletes: how sport has damaged America and preserved the myth of race. Boston: Houghton Mifflin 1997 15. Wiggins DK, ‘Great speed but little stamina’; the historical debate over Black athletic superiority. In: Pope SW, ed. The New American Sport History. Chicago IL: University of Illinois Press, 1997: 312-338 16. Psychol Sci 2001;12:225-9 17. Spielberger CD: Stress and anxiety in sports. In: Hackfort D, Spielberger CD, eds, Anxiety in sports. New York: Hemisphere, 1989:3-17 18. Spielberger CD: Theory and research on anxiety. In: Spielberger CD, ed, Anxiety and behavior. New York: Academic Press, 1996:1-17 19. Smith RE, Smoll FL, Wiechman SA: Measurement of trait anxiety in sport. In: Duda JL ed, Advances in sport and exercise psychology measurement. Morgantown WV: Fitness Information Technology, 1998:105-27 20. Gould D, Krane V: The arousal-athletic performance relationship: current status and future directions. In: Horn T, ed, Advances in sport psychology. Champaign IL: Human Kinetics, 1992:119-41 21. Quest 1994;460-77 22. Journal of Human Movement Studies 1987;13:211-29
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References
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SOCCER ARTICALS 23. Martens R: Coach’s guide to sport psychology. Champaign IL: Human Kinetics, 1987 24. Fox KR: The physical self: from motivation to well being. Champaign IL: Human Kinetics, 1997: 25. Am Psychol 1997;52:613-29 26. Pers Soc Psychol Bull 2003; in press 27. Duda JL: Sport and exercise motivation: a goal perspective analysis. In: Roberts G, ed, Motivation in sport and exercise. Champain IL: Human Kinetics, 1992:57-91 28. Coakley J: Sport and society: issues and controversies, 7th ed. New York: McGraw-Hill, 2001
Ethiopian endurance running In the increasingly competitive world of international sport, identifying the key predictors of success has become a major goal for many sports scientists. And nowhere has the hunt been more focused than in East Africa, where the overwhelming success of male endurance athletes has kept the nature v nurture debate simmering. Saltin’s famous study comparing Kenyan and Scandinavian athletes suggested that it was the distance the Kenyans travelled to school on foot in childhood that gave them an edge in endurance athletics. That theory has now received further backing from a major British study comparing the demographic characteristics of Ethiopian athletes with non-athlete controls from the same country.
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Nature and nurture in Ethiopian endurance running success
An additional fascinating finding was that élite Ethiopian distance runners are ethnically distinct from the general Ethiopian population, raising the possibility that genetic factors might also be involved. Questionnaires seeking information on place of birth, spoken language (by self and grandparents), distance from and method of travel to school were given to 114 male and female members of the Ethiopian national athletics team and 111 Ethiopian controls, none of whom were regularly training for any track or field athletic events. The athletes were separated into three groups for comparison: marathon runners (34), 5-10km runners (42) and other track and field athletes (38). After analysis, the main findings were as follows: In terms of regional distribution, there was a significant excess of athletes,
particularly marathoners, from the Arsi and Shewa regions of Ethiopia. 73% of marathon runners hailed from one of these two regions, compared with 43% of 5-10km runners, 29% of track and field athletes and just 15% of controls. To
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Where does this leave the nature v nurture debate? The findings about travel to school undoubtedly point to environmental influences, as the researchers acknowledge. ‘…the results implicated childhood endurance activity as a key selection pressure in the determination of Ethiopian endurance success,’ they say. ‘With the prevalence of childhood obesity in the United States and Great Britain at an all- time high, and physical activity levels among such populations in stark contrast to the daily aerobic activity of Ethiopian children, these factors may offer an explanation for the success of East-African athletes on the international stage.’ On the other hand, the findings about regional and ethnic origins point to genetic influences. Or do they? The regions of Arsi and Shewa are situated in the central highlands of Ethiopia, intersected by the very same Rift Valley that has been implicated in the success of Kenyan endurance runners. This may seem to support a link between altitude and endurance success. But it doesn’t explain why Arsi is also considerably overrepresented in track and field athletes (18%), who would not be expected to benefit from living and training at altitude.
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put those figures in context, Arsi is the smallest of Ethiopia’s 13 regions, accounting for less than 5% of the total population, but housing 38% of the marathon athletes in this study; The origin of language of all the athlete groups differed significantly from that of the controls. Three separate language categories were used: Semitic, Cushitic and Other; and Cushitic was significantly more predominant in each of the athlete groups than among the controls. The effect was most pronounced in the marathon group, where 75% spoke languages of Cushitic origin compared to 30% of controls; In terms of distance travelled to school, the marathon athletes differed significantly from all other groups. 73% of marathoners travelled more than 5k to school each day, compared with 32-40% of the other groups. And marathoners were much more likely to run to school each day than the other groups (68% v 16-31%).
The researchers put forward an alternative, somewhat more prosaic, hypothesis. ‘One of the senior Ethiopian athletic coaches informed the investigators that most of the marathon athletes would be found to be from Arsi,’ they explain. ‘If those in charge of athletic development believe this, it may cause a self-fulfilling prophecy through talent scouts focusing more attention to this region or through increased regional development of athletics.’ What of the findings about language? The fact that most of the marathoners spoke languages of Cushitic origin (mostly Oromigna, the language of Oromo people) ‘may reflect a high frequency of potential “performance genes” within this particular group.
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SOCCER ARTICALS ‘However, it is much more likely,’ the researchers add, ‘that the distinctive ethnic origin of the marathon athletes is a reflection of their geographical distribution, as primarily Oromo people populate Arsi. ‘Although not excluding any genetic influence,’ they conclude, ‘the results of the present study highlight the importance of environment in the determination of endurance athletic success.’ Med Sci Sports Exerc, vol 35, no 10, pp1727-1732
Are athletes turning to genetic modification and is drug abuse in sport getting worse? It's a crying shame when a once proud athlete hits the bottle. It can be even more of a shame - and frightening too - if that bottle contains a genetic cocktail that might forever change the competitive balance in sports. And in this Frankenstein world where genetics meets athletics, the future is now. 'I think certain methods could have already started,' says Johann Olav Koss, the 1994 speed skating champion from Norway who is a member of the International Olympic Committee (IOC) and a doctor. In many competitive sports, the difference between the gold medal and also-ran status is a fraction of a second. No wonder everyone is looking for any edge that technology might offer. Athletic improvements over the past decade have come to depend more and more on scientific advances in training, nutrition, and even surgical enhancements. But perhaps the biggest boost has come from performance-enhancing additives.
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Genetic engineering and drug abuse
With the widespread use of steroids, human growth hormone and EPO (Erythropoietin, a hormone that regulates red blood cell production, used to increase the oxygencarrying capacity, and hence the performance, of endurance athletes), runners, bikers, or swimmers leaning into the wind and water have every reason to eye their competitors suspiciously. Now the cornucopia of easily available and easily disguisable pharmaceuticals is joined by the latest and most controversial competitive weapon genetic engineering. Several promising performance-enhancing gene modifications have already been successfully tested on animals. They include generating the growth of explosive, fasttwitch muscle fibres and stimulating the release of growth-hormone-releasing hormone (GHRH), which can make recipients both stronger and leaner. Medical applications of gene therapy on humans to cure or prevent disease are at a rudimentary but fast-evolving stage. Instead of treating deficiencies by injecting
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SOCCER ARTICALS drugs, doctors soon will be able to prescribe genetic treatments that will induce the body's own machinery to produce the proteins needed to combat illnesses. 'It's not rocket science,' says Theodore Fridemann, director of the gene therapy programme at the University of California at San Diego and a member of the medical research committee of the World Anti-Doping Agency (WADA). 'If you asked any student of molecular biology how he would implant genes to change muscle function, he could cite three or four ways to do it.'(1)
Two years ago, He-Man was injected with a synthetic version of a gene called Insulinlike Growth Factor 1 (IGF-1), a protein that makes muscles grow and repair themselves. Today, deep into old age, the once tiny mouse and his gene-modified brothers and sisters look more like the Turkish weight-lifting icon Naim Suleymanoglu. After the IGF-1 boosted He-Man's muscle mass by more than 60%, he can now climb a ladder carrying three times his body weight. 'We call them the Schwarzenegger mice,' says Nadia Rosenthal, an associate professor at Harvard Medical School who coauthored the study. 'I'd be totally surprised if it was not going on in sports. Those with terminal cancer and Aids want to know 'What will keep me alive?' Athletes want to know 'What will help me win?''(2) As the drug-addled East German and Soviet sports systems demonstrated, athletes and their managers are willing to strike Faustian bargains to achieve immediate glory. But this was no Communist-specific phenomenon: in a 1995 survey of nearly 200 aspiring American Olympians, more than half said they would take a banned substance that would guarantee victory in every competition for five years even if it would lead to certain death.
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The model cited by scientists on the cutting edge of sports science - the experimental patient that sends shivers down the back of the Greenes, the Kipketers, and the Khannouchis of this world - is 'He-Man', a mouse running endless, tireless circles in his basement laboratory cage at a University of Pennsylvania physiology laboratory.
Where mice lead in the lab, athletes will follow in the field 'I have no doubt that if this is being done on mice, humans aren't far behind,' says Bengt Saltin, a former competitive runner, head of the Copenhagen Muscle Research Institute, and also a member of WADA. 'It would be risky because of unknown side effects but the basic genetic advances have been made. If scientists are willing to cooperate, athletes will experiment on themselves.' Like ordinary genes, the artificial genes consist of DNA, the basic raw materials of human life. The direct delivery approach would be to inject the DNA into the muscle. The fibres would then take up the DNA and add it to the normal pool of genes. As this method is not yet very efficient, researchers often use viruses to carry the gene payload into a cell's nuclei. That's how the IGF-1 gene was delivered to make He-Man. Unfortunately, in contrast to the direct injection, the genes are also delivered to many other cells, such as those of the blood and liver, in addition to the intended target. A third approach entails removing specific cell types from the patient, adding the artificial gene in the laboratory and reintroducing the cells into the body. Since the artificial genes would produce proteins that in many cases are identical to the
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SOCCER ARTICALS normal proteins, that means you can kiss good-bye to effective policing by sports agencies.
Just a few injections of this DNA into the quadriceps, hamstring, and gluteus, and the muscle fibres will start cranking out Velociphin, which will activate the fast myosin gene. In weeks, the muscles bulge and burst with energy. There are no visible sideeffects and without a muscle biopsy directly into manipulated muscle, the genetic modification is undetectable. It's the long-awaited race for Olympic immortality. BANG! The genetically doped athlete dashes into the lead, extending it with every stride. Then at 65 metres, far out in front of the field, a sudden twinge tickles the hamstring. Saltin picks up the story. At 80m, the twinge explodes into an overwhelming pain as he pulls his hamstring. A tenth of a second later the patella tendon gives in, because it is no match for the massive forces generated by his quadriceps muscle. The patella tendon pulls out part of the tibia bone, which then snaps, and the entire quadriceps shoots up along the femur bone. The athlete crumples to the ground, his running career over. 'This is not the scenario that generally comes to mind in connection with the words 'genetically engineered super athlete',' notes Saltin, but it is part of the reality.(3) For example, researchers have genetically altered a housefly with muscles 300% stronger than normal. It may sound promising, but 'the fly actually lost power because it couldn't make its wings move fast enough' to support the added muscle weight, notes H. Lee Sweeney, co-author of the He-Man study.(1) While society has come to view the human body as an invincible machine, it is in fact a resilient but still delicate balance of tendons, cartilage, muscle, and fat. This is a balance that some fear may be altered radically, permanently, and perhaps perilously by genetic manipulation.
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Bengt Saltin has a recurring nightmare. He imagines a scenario in which an already elite sprinter obsessed with becoming the world's fastest human turns to a renegade geneticist familiar with the latest research on the genetic modification of muscle fibre types. As powerful as the human musculature may appear to be to the layman, it can't hold a candle, relatively, to the explosive capacity of the muscles of many mammals, including mice, who call on energy bursts to elude predators. Although the fastest muscle fibre types are not found in human skeletal muscle, the potential for developing such fibres are imbedded in long dormant genes. Geneticists have recently developed a protein known as a 'transcription factor' called Velociphin, which can activate these genes.
Aside from ethical concerns, there's a practical problem. This has understandably provoked a host of medical and ethical concerns. 'The only thing keeping athletes from using genetic manipulation today is the control problem,' says Saltin. 'You can't shut the production off when you want to.' For example, muscles injected with Velociphin will continue to produce the explosive fibres without further injection. Geneticists experimenting with the gene that codes for EPO have discovered that a single injection into the leg muscles of monkeys produced significantly elevated red blood cell levels for 20 to 30 weeks. That could prove to be a boon for anemia patients and provide a performance boost for endurance athletes except for one key problem: in
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SOCCER ARTICALS the absence of a mechanism to shut down production, the body could turn into a outof-control EPO factory, leading to the thickening of the blood with excessive blood cells, strokes, heart attacks, and eventually death.
With all of these Frankenstein-like scenarios, it would seem an easy decision to ban genetic engineering of athletes on ethical grounds. 'The argument in favour of allowing people to do this is based on our tradition of giving individuals a huge amount of autonomy over their own bodies,' says Eric Juengst, an ethicist at Case Western Reserve University in Cleveland. 'The limits on that kind of freedom are interpersonal. Once your actions cross the line of affecting just yourself and begin to affect other people, we have licence to step in.'(5) Surprisingly, not everyone agrees, and in fact the ethical issues turn very murky on close examination. The current anti-doping rules do not permit the use of steroids even if prescribed for genuine medical reasons, eg to hasten recovery after an injury. Yet that is exactly how gene modification in athletes will first be used - say an injection of IGF-1 to stimulate muscle regeneration. Its use could theoretically allow an athlete to perform at an optimal level years past what is now considered his prime. Or imagine an athlete using gene modification to help overcome congenital asthma or some other genetic abnormality.
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But such problems offer only temporary barriers. Helen Blau, chairwoman of the department of molecular pharmacology at Stanford Medical School, has demonstrated that a gene could be introduced into a mouse to stimulate growth hormone in the bloodstream and then be switched off with the use of an oral antibiotic. 'In theory, it is possible that an athlete could be genetically engineered to have a gene so you could increase muscle strength, train with it and shut it off when you want to,' she says.(4) Not only would such a development prevent inserted genes from spinning out of control, they would render drug screening almost impossible.
IOC President Jacques Rogge waded into this ethical thicket earlier this year. 'Genetic manipulation is there to treat people who have ailments, not there to treat a healthy person,' he says. 'I am very clear on this.' Very few geneticists or ethicists have quite the same level of clarity. There is a very hazy and debatable line separating 'health restoration' and 'performance enhancement'.(6) The case of Helen Smith, an internationally renowned swimming star from Britain comes to mind. Smith who competes as a quadriplegic was threatened with a ban at the 2000 Sydney Paralympics for receiving medication that is life-sustaining for her but was deemed performance-enhancing by Olympic officials. There is already an equal access controversy in elite sports between wealthier countries which employ cutting edge technology in equipment, nutrition, and medicines versus the rest of the world who just muddle along. What makes genetic engineering any different as long as its focus is in overcoming some real - or perceived - injury-related performance deficiency? A further question arises about any kind of genetic manipulation that is introduced before birth by a well-meaning parent. As Maurice Greene has noted: 'What if you're born with something having been done to you?' Would manipulation of an egg or an
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SOCCER ARTICALS embryo be considered cheating, if as Greene hypothesises, 'you don't have anything to do with it?'(7) It might be unfair to penalise someone for an enhanced genotype but it is understandably problematic to have that person compete against a non-enhanced athlete. Considering the health dimension of genetic enhancement, it certainly appears to be a more acceptable method of performance enhancement than drugs. The IOC has set up a 'gene doping' advisory group but seems befuddled by these complex issues. 'The information from genetic science will feed through into better treatments for disease, but it also going to present the sports industry with a Pandora's box within the next five to 10 years,' says Bruce Lynn, a senior neurophysiologist at University College London's School of Human Health and Performance.
Perhaps. From a purely competitive standpoint, athletics might be more exciting, pushing the edge of human capability, testing the limits of speed and endurance well beyond those that science currently accepts. Until the patella tendon and quadriceps snap and a once valiant athlete is carted off the track, perhaps never to walk again.
Jon Entine References: 1, Swift, EM & Yaeger, D, Irish Examiner (July 10, 2001) 2 Cromie, WJ, Harvard Gazette (Feb 11, 1999) 3 Andersen, JL, Schjerling, P & Saltin B, Scientific American (Sept 2000) 4 Longman, J, New York Times (May 11, 2000) 5 Compton M, DNA Dispatch (July 2001) 6 Clarey, C, Intl Herald Tribune (Jan 26, 2001) 7 Chandel, A, Tribune (India) (May 18, 2001)
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There has even been talk of introducing a handicap for genetically enhanced contestants or even setting up official performance-enhanced competitions. 'That's a terrible idea,' bemoans Saltin. 'If genetic engineering is sanctioned, it's the end of sports as we know it. Sports will be a circus of unbelievable performances.'
Summer and winter athletes: the best sprinters are born in summer and the best distance runners in the winter A babies birth date can determine whether they will be a runner or a sprinter! Many of Britain's top sprinters were born in the summer and, perhaps even more strikingly, most of Britain's best long distance men were born in the winter. That was a
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I looked at the top men at both 100m and 10,000m to the end of 1982, and noted that of the top 12 at 100m (excluding Trevor Hoyte who was not born in Britain), five were born in May, as were three others just outside that list. Five of the top six men at 10,000 metres as well as the previous UK record holder, Dick Taylor, were born in December/January. I wrote at the time that one could get carried away by what might have been a series of amazing coincidences, but a flight of fancy might lead one to say that if 100m men are born in the height of summer and 10,000m men in the middle of winter, then the middle distance men would be somewhere in the middle. Sure enough: Sebastian Coe was born on September 29, Steve Ovett on October 9, Steve Cram on October 14, Peter Elliott on October 9, David Moorcroft on April 10, Frank Clement on April 26 (all world-class milers). There is plenty of divergence after that, but, wow! the top men certainly fit the pattern. The top 13 lists at that time showed:
100 metres Allan Wells 3/5 Ainsley Bennett 22/7 Cameron Sharp 3/6 Peter Radford 20/9 Mike McFarlane 2/5 Brian Green 15/5 Barrie Kelly 2/8 David Jenkins 25/5 Drew McMaster 10/5 Trevor Hoyte 5/1* Jim Evans 10/4 Ron Jones 19/8 Steve Green 13/10 * born in Trinidad
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discovery that I made some 20 years ago and about which I wrote in Running Magazine in 1983. I did not begin to ascribe any astrological significance to this - and any competent astronomer would tell you that astrology is complete nonsense. However, it did lead me to wonder if there just might be some significance in my findings perhaps something to do with climatic factors at the time of birth?
10,000 metres Brendan Foster 12/1 David Bedford 30/12 Julian Goater 12/1 David Black 2/10 Mike McLeod 25/1 Ian Stewart 15/1
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SOCCER ARTICALS Tony Simmons 6/10 Bernie Ford 3/8 Geoff Smith 24/10 Adrian Royle 12/2 David Clarke 1/1 Steve Jones 4/8 Nick Rose 30/12 These were a strikingly different set of birth dates, but I noted that the theory did not work so well for the marathon, although there was still a definite winter bias.
UK top 13s at 100m and 10,000m
100 metres Linford Christie 2/4 Dwain Chambers 5/4 Jason Gardener 18/9 Darren Campbell 12/9 Jason Livingston 17/3 Mark Lewis-Francis 4/9 Allan Wells 3/5 Christian Malcolm 3/6 Darren Braithwaite 20/1 Marlon Devonish 1/6 Michael Rosswess 11/6 John Regis 13/10 Ian Mackie 27/2
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So, let us revisit the subject - and examine the current situation. Here are the current UK top 13s for these events.
10,000 metres Jon Brown 27/2 Eamonn Martin 9/10 Brendan Foster 12/1 David Bedford 30/12 Nick Rose 30/12 Julian Goater 12/1 David Black 2/10 Steve Jones 4/8 Mike McLeod 25/1 Richard Nerurkar 6/1 Ian Stewart 15/1
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SOCCER ARTICALS Tony Simmons 6/10 Bernie Ford 3/8 A quick glance shows that the story remains much the same, with of course a few exceptions, such as Darren Braithwaite at 100m and Steve Jones at 10,000m. But the astonishing fact is that seven of the top 11 at 10,000m were born within a four-week period from December 30 to January 25. Of course, with the collapse in distance running in the developed world, the list at 10,000m has not changed so much, and is likely to be pretty static in future, as the lack of an endurance base in the current generation of children is reflected in everdeclining distance running standards in Britain (and Finland, Sweden, USA, etc).
Jon Brown (1st) 27/2 Karl Keska (15th) 7/5 Keith Cullen (19th) 13/6 Andrew Jones (27th) 3/2 Rob Denmark (30th) 23/11 Mark Steinle (33rd) 22/11 John Nuttall (37th) 11/1 Glynn Tromans (60th) 17/3 Martin Jones (84th) 21/4 Ian Hudspith (89th) 23/9 Keska and Cullen are summer babies, but there remains a winter bias. One man not mentioned above, but Britain's most successful cross-country runner of the past 20 years, is Tim Hutchings - and he was born on December 4.
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But I next looked at the top men who are currently performing, again in order of ranking, from the UK 10,000m all-time list:
British top 10 six-milers to 1962 To test the theory further I thought that I should also look back in time, so I went back 20 years and took the British top 10 for 6 miles/10,000m to 1962: Roy Fowler 26/3 Mike Bullivant 1/3 Martin Hyman 3/11 Mel Batty 9/4 Bruce Tulloh 28/9 Basil Heatley 28/12 Stan Eldon 1/5 George Knight 12/3
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SOCCER ARTICALS John Merriman 27/6 Gordon Pirie 10/2 This showed nothing like the same mid-winter story, although there were only two born in the summer. In my original study I only looked at men. So what about the women? Does the birth date theory hold for them? Well, world half-marathon champion Paula Radcliffe was born on December 17 and that fits the bill pretty well, but Liz McColgan was born on May 24, which doesn't at all. However, Kathy Cook, our top sprinter, fits the pattern as she was born on May 3.
Paula Radcliffe 17/12 Liz McColgan 24/5 Jill Hunter 14/10 Wendy Sly 5/5 Angela Tooby 24/10 Yvonne Murray 4/10 Kathy Butler 22/10 Susan Tooby 24/10 Andrea Wallace 22/11 Susan Crehan 12/9 All but one appeared in the world between mid-September and mid-December.
Climate may be an influence; sedentary lifestyle certainly is
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Here, then, are the birth dates for the current British women's top 10 at 10,000m:
I am sure that physiological factors, such as the possession of slow-twitch and fasttwitch fibres are of much greater importance than birth dates. And then we come to the question of genetic factors, which must surely play some part in determining the physiological profile of an individual. But in my studies of athletics I have seen that all types of athletes can come from the wide range of racial types, and am concerned that writers such as Jon Entine appear to have written-off the white races for distance running, while ignoring many of the causes of this (PP 158 December 2001.) I believe that socio-economic factors play a huge part in the fate of the men or women who rise to the top, and the drastic decline in Western distance running is most certainly not caused by genetic factors, but by the fact that our youngsters are much
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SOCCER ARTICALS more sedentary than people of 20-30 years earlier, with the result that our top juniors are running very much slower over 3000m and 5000m than they used to. While the 'hungry fighters' from Africa and other impoverished parts of the world are prepared to sacrifice their creature comforts for the dedicated hard work that is needed to make a top distance runner, fewer from our society are prepared to do so. But environment is surely important. For instance, distance runners are less likely to develop if living in large towns, and I note that nearly all the top Spanish distance runners in their recent resurgence have come from rural districts, and the East Africans have the added bonus of high altitude.
Peter Matthews
The menopause: hormone replacement therapy decreases the risk of heart disease & bone loss & maintains muscle performance The effect of HRT after the menopause Hormone replacement therapy (HRT) after menopause is widely believed to counteract the increased risk of heart disease and bone loss which accompanies the loss of the female sex hormones, particularly oestrogen. And now new research from Finland suggests that HRT also plays a key role in maintaining post-menopausal muscle performance, which is good news for women in general and female athletes in particular. Even better is the implication that the benefits of HRT combined with highimpact physical training exceed those of either HRT or training alone.
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No distance runners are going to come from the hot and humid countries of West Africa or even perhaps from the drier Caribbean. And just maybe, the climatic factors before or after birth might, as indicated above, make some difference in the temperate climes of Britain.
This one-year study of 80 women aged 50-57 is the first randomised double-blind placebo-controlled trial - the gold standard of scientific research - to investigate the effects of HRT on muscle performance and muscle mass. The women were assigned to one of four groups: exercise; HRT; exercise-plus-HRT; and control. The exercise groups embarked on a 12-month progressive physical training programme that included a twice-weekly supervised circuit training session and a series of exercises performed at home four times a week. The circuit training sessions varied, but all included three or four of the following: resistance exercises for the upper body; chest fly; latissimus pull down; military press; seated row; biceps curl. The home exercise programme was also designed as a circuit training routine, including skipping, hopping, drop jumping and exercises to strengthen the abdominal and lower back
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SOCCER ARTICALS regions. The control group took dummy tablets daily as did the exercise-only group, while the women in the two non-exercise groups were told to continue their normal daily routines without changing their physical activity levels. Various measures of muscle performance and mass were taken before the start of the study and at six and 12 months. By six months 18 of the original participants had dropped out for a variety of reasons, leaving 62 spread across the four groups. By 12 months that number had been whittled down to 52. Key results were as follows:
Slight increases in vertical jumping height - an indication of muscle power production were seen in both the exercise and HRT groups after six and 12 months when compared with the controls. But the differences were more marked in the exerciseplus-HRT group; After 12 months, women in the HRT and exercise-plus-HRT groups showed increases in the muscle mass of their quadriceps and lower leg in comparison with the exerciseonly and control groups. Again, the differences were most marked in the group combining exercise with HRT. 'The independent effect of HRT on skeletal muscle mass and performance is probably the most interesting finding in the present study,' comment the authors. 'The resultsÉ suggest that continuous administration of oestradiol/noretisterone acetate [a combined HRT preparation] has beneficial effects on muscle performance, muscle mass and muscle composition in early post-menopausal womenÉ The results also suggest that the effects of HRT combined with high-impact physical training may exceed those of the two treatments separately.'
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Over the course of the study lean body mass increased in all except the control group; Women in the exercise and HRT groups showed an increase in maximal isometric knee extension force after six months compared with the controls. But after 12 months of follow-up, only the exercise-plus-HRT group differed significantly from the controls;
Clin Sci (Lond) 2001 Aug 101(2), pp 147-57 Isabel Walker
genetics | sports performance Genetics and Performance: Now science is getting to the long and the short of how genes influence performance Scientists are slowly beginning to find the genes which play a direct role in determining exercise capacity. Recently, researchers discovered - on human chromosome No. 1 - the gene which encodes MCT1, a protein which helps transport lactate into muscle cells. Variations in this gene will no doubt determine how well an athlete can improve lactate threshold - a key predictor of endurance performance - in response to strenuous physical training.
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To understand how variations in the ACE gene might influence the economy with which you run, cycle, or swim, you first need to understand what angiotensin-converting enzyme actually does. The angiotensin-converting-enzyme story begins with a plasma protein called angiotensinogen, which is present in the blood of all human beings. Under certain conditions, kidney cells secrete a hormone called renin into the blood which cleaves a 10-amino-acid protein from angiotensinogen to form a compound called angiotensin I. The various physiological roles played by angiotensin I are not completely understood, but it is known that angiotensin-converting enzyme (ACE) can knock two amino acids off angiotensin I to form a compound called angiotensin II. Angiotensin II has a variety of functions, but for purposes of our discussion we can simply say that it directly increases blood pressure by constricting arteries, and it indirectly raises blood pressure and blood volume by stimulating thirst centres in the brain and directing the kidneys to conserve more minerals and water. The British scientists knew that there were two key variations in the ACE gene (the one which codes for angiotensin-converting enzyme). One of these has an extra 287 base pairs within its DNA and is called the 'long allele'; the other is without the base pairs and is the 'short allele'. All humans have two ACE genes; roughly 50 per cent of the world's population has one copy of each variant, 25 per cent have two short genes, and 25 per cent have the two long ones. Previous studies had shown that the long allele seems to be linked with better endurance performance and a stronger response to exercise training. For example, in one piece of research individuals with two copies of the long allele gained more muscle mass and lost more body fat during 10 weeks of intensive physical training, compared with athletes with two copies of the short gene or one copy of each gene ('Angiotensin-Converting Enzyme Gene Insertion/Deletion Polymorphism and Response to Physical Training,' Lancet, vol. 353 (9152), pp. 541-545, February 13, 1999).
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ow, scientists at the Royal Defence Medical College and the Centre for Cardiovascular Genetics in the UK have discovered that variations in the gene which encodes a protein called angiotensin-converting enzyme (ACE) can have a large impact on exercise efficiency ('The ACE Gene and Muscle Performance,' Nature, vol. 403, p. 614, 10 February 2000).
The British researchers were not sure why that was the case, but they did know that the long allele produces a version of angiotensin-converting enzyme which is 'weaker', i. e., has lower activity, compared with the short gene. To gain a better understanding of the long-gene's effects, they recruited 58 Caucasian military servicemen into their study; 35 had two copies of the long version of the gene, and 23 possessed just the short version. All 58 men underwent an 11-week programme of endurance exercise consisting of interval training on an exercise bike. Delta efficiency Prior to and after the training period, the researchers calculated the 'delta efficiency' of exercise for each subject. This variable is supposed to represent the efficiency with which muscles are working, and it is basically the percentage ratio of the change in work performed per minute to the change in energy expended per minute. Delta
163
SOCCER ARTICALS efficiency is not a bad way to measure one's economy of exercise; basically, it reflects the fact that if you can increase your rate of working per minute (i. e., your muscular power output) without a large upswing in energy expenditure, you are efficient; if your energy consumption soars when you increase your running, cycling, or swimming speed, you are inefficient. Before the training began, the delta efficiency was the same for both groups of men (about 25 per cent). However, after training delta efficiency improved by almost 9 per cent for exercisers with two copies of the long ACE gene but remained stagnant in the short-ACE group.
At least some of this artery expansiveness is mediated by a chemical called nitric oxide which is released by cells lining your arteries (these cells help make up the 'endothelium' - the inner layer of artery walls). Nitric oxide - 'discovered' by scientists about 20 years ago and originally thought to be an intracellular 'messenger' - not only dilates arteries but also prolongs vasodilation, keeping the good stuff flowing into your muscle cells throughout your workout or race. Incidentally, nitric oxide's actions are so powerful that nitric-oxide treatments reduce pulmonary vascular resistance in people with severe chronic obstructive pulmonary disease and are also thought to be helpful in the treatment of atherosclerosis. Train to release nitric oxide Exercise training increases the production of nitric oxide by your endothelium, but angiotensin II seems to decrease the rate at which nitric oxide is synthesized. Thus, we have a potential mechanism underlying the long-ACE-gene's link with better endurance performance. The long gene produces angiotensin-converting enzyme with lower activity, which means that less angiotensin II will be produced. The lower angiotensin II means that more nitric oxide can be synthesized inside artery walls during exercise, leading to stronger blood flow to the muscles. In effect, the long ACE genes let endurance-trained muscles have more blood.
SOCCER ARTICALS | FOOT BALL
What was going on? Bear in mind that one of the key - but often overlooked adaptations you make to exercise training is in the responsiveness of your blood vessels. After you have been exercising regularly for a couple of months, your blood vessels relax more easily during exercise, increasing blood flow to your muscles. This has some obvious advantages; the spiked blood flow can bring more oxygen and fuel to your muscle fibres.
It's not clear yet why this effect would improve efficiency of exercise (it seems more likely to raise VO2max and lactate threshold), unless the muscle cells most responsible for efficient movement are better supplied by oxygen and fuel in individuals with the longer ACE gene - and thus can work more continuously throughout a bout of exercise. The exercise intensities utilized in the study were low (no higher than 80 Watts), so it's possible that the combination of long ACE genes plus training opened up blood flow to slow-twitch muscle cells in the exercisers' legs, allowing them to 'take over' the burden of exercise (slow-twitch cells would be more efficient than fast twitchers at low intensities of exertion). However, Dr. Hugh Montgomery, lead scientist in the study, believes that another mechanism may be at work. Montgomery thinks that the long ACE genes may have profound metabolic effects within the muscle cells, in addition to
164
SOCCER ARTICALS their influence on artery walls. Basically, he suggests that the long genes may improve the efficiency of fuel selection, uptake, and utilization by muscle fibres during exercise, thus enhancing economy.
Of course, many will wonder whether Kenyan runners have the long-ACE genes (but probably won't speculate on how the Ethiopians were able to borrow those ACEs from the Kenyans, or how the Kenyans picked up the genes from the Finns, who borrowed them from the Brits, who took the alleles from earlier Finns, who got them from Swedes, etc.). Before this kind of thinking goes too far, however, we should point out that about 25 per cent of British and American citizens have double-long ACE genes, which in the case of Americans would mean that almost three times as many Americans hold double ACEs, compared to Kenyans, even if the entire Kenyan population had only the extended genes! It is clear that the research has implications which range beyond endurance exercise. Drugs called 'ACE inhibitors' help cardiac cells survive heart attacks and also improve survivorship in patients with heart troubles of various kinds by easing artery tightening and perhaps in part by letting nitric oxide do its thing and improving the efficiency of cardiac muscle-cell contractions. ACE inhibitors might also help increase the mechanical and metabolic efficiency of muscles in individuals who for various reasons are energy-deprived. The ACE work is exciting stuff, uncovering not only the genetic but also the important physiological foundations of exercise excellence. In our next issue, we'll provide you with a review of what scientists actually know about the genetic underpinnings of performance.
SOCCER ARTICALS | FOOT BALL
The ACE of hearts Before rushing out to your local exercise geneticist to find out if you have the long version of ACE, bear in mind this caveat, however: so far, the efficiency improvement has only been detected at very low exercise intensities; we don't know if it will hold true at competitive speeds, too.
Owen Anderson
Genetics and Performance Genetics And Performance: Now science is getting to the long and the short of how genes influence performance Scientists are slowly beginning to find the genes which play a direct role in determining exercise capacity. Recently, researchers discovered - on human chromosome No. 1 - the gene which encodes MCT1, a protein which helps transport lactate into muscle cells. Variations in this gene will no doubt determine how well an
165
SOCCER ARTICALS athlete can improve lactate threshold - a key predictor of endurance performance - in response to strenuous physical training.
To understand how variations in the ACE gene might influence the economy with which you run, cycle, or swim, you first need to understand what angiotensin-converting enzyme actually does. The angiotensin-converting-enzyme story begins with a plasma protein called angiotensinogen, which is present in the blood of all human beings. Under certain conditions, kidney cells secrete a hormone called renin into the blood which cleaves a 10-amino-acid protein from angiotensinogen to form a compound called angiotensin I. The various physiological roles played by angiotensin I are not completely understood, but it is known that angiotensin-converting enzyme (ACE) can knock two amino acids off angiotensin I to form a compound called angiotensin II. Angiotensin II has a variety of functions, but for purposes of our discussion we can simply say that it directly increases blood pressure by constricting arteries, and it indirectly raises blood pressure and blood volume by stimulating thirst centres in the brain and directing the kidneys to conserve more minerals and water. The British scientists knew that there were two key variations in the ACE gene (the one which codes for angiotensin-converting enzyme). One of these has an extra 287 base pairs within its DNA and is called the 'long allele'; the other is without the base pairs and is the 'short allele'. All humans have two ACE genes; roughly 50 per cent of the world's population has one copy of each variant, 25 per cent have two short genes, and 25 per cent have the two long ones. Previous studies had shown that the long allele seems to be linked with better endurance performance and a stronger response to exercise training. For example, in one piece of research individuals with two copies of the long allele gained more muscle mass and lost more body fat during 10 weeks of intensive physical training, compared with athletes with two copies of the short gene or one copy of each gene ('Angiotensin-Converting Enzyme Gene Insertion/Deletion Polymorphism and Response to Physical Training,' Lancet, vol. 353 (9152), pp. 541-545, February 13, 1999).
SOCCER ARTICALS | FOOT BALL
Now, scientists at the Royal Defence Medical College and the Centre for Cardiovascular Genetics in the UK have discovered that variations in the gene which encodes a protein called angiotensin-converting enzyme (ACE) can have a large impact on exercise efficiency ('The ACE Gene and Muscle Performance,' Nature, vol. 403, p. 614, 10 February 2000).
The British researchers were not sure why that was the case, but they did know that the long allele produces a version of angiotensin-converting enzyme which is 'weaker', i. e., has lower activity, compared with the short gene. To gain a better understanding of the long-gene's effects, they recruited 58 Caucasian military servicemen into their study; 35 had two copies of the long version of the gene, and 23 possessed just the short version. All 58 men underwent an 11-week programme of endurance exercise consisting of interval training on an exercise bike. Delta efficiency Prior to and after the training period, the researchers calculated the 'delta efficiency' of exercise for each subject. This variable is supposed to represent the efficiency with which muscles are working, and it is basically the percentage ratio of the change in
166
SOCCER ARTICALS work performed per minute to the change in energy expended per minute. Delta efficiency is not a bad way to measure one's economy of exercise; basically, it reflects the fact that if you can increase your rate of working per minute (i. e., your muscular power output) without a large upswing in energy expenditure, you are efficient; if your energy consumption soars when you increase your running, cycling, or swimming speed, you are inefficient. Before the training began, the delta efficiency was the same for both groups of men (about 25 per cent). However, after training delta efficiency improved by almost 9 per cent for exercisers with two copies of the long ACE gene but remained stagnant in the short-ACE group.
At least some of this artery expansiveness is mediated by a chemical called nitric oxide which is released by cells lining your arteries (these cells help make up the 'endothelium' - the inner layer of artery walls). Nitric oxide - 'discovered' by scientists about 20 years ago and originally thought to be an intracellular 'messenger' - not only dilates arteries but also prolongs vasodilation, keeping the good stuff flowing into your muscle cells throughout your workout or race. Incidentally, nitric oxide's actions are so powerful that nitric-oxide treatments reduce pulmonary vascular resistance in people with severe chronic obstructive pulmonary disease and are also thought to be helpful in the treatment of atherosclerosis. Train to release nitric oxide Exercise training increases the production of nitric oxide by your endothelium, but angiotensin II seems to decrease the rate at which nitric oxide is synthesized. Thus, we have a potential mechanism underlying the long-ACE-gene's link with better endurance performance. The long gene produces angiotensin-converting enzyme with lower activity, which means that less angiotensin II will be produced. The lower angiotensin II means that more nitric oxide can be synthesized inside artery walls during exercise, leading to stronger blood flow to the muscles. In effect, the long ACE genes let endurance-trained muscles have more blood.
SOCCER ARTICALS | FOOT BALL
What was going on? Bear in mind that one of the key - but often overlooked adaptations you make to exercise training is in the responsiveness of your blood vessels. After you have been exercising regularly for a couple of months, your blood vessels relax more easily during exercise, increasing blood flow to your muscles. This has some obvious advantages; the spiked blood flow can bring more oxygen and fuel to your muscle fibres.
It's not clear yet why this effect would improve efficiency of exercise (it seems more likely to raise VO2max and lactate threshold), unless the muscle cells most responsible for efficient movement are better supplied by oxygen and fuel in individuals with the longer ACE gene - and thus can work more continuously throughout a bout of exercise. The exercise intensities utilized in the study were low (no higher than 80 Watts), so it's possible that the combination of long ACE genes plus training opened up blood flow to slow-twitch muscle cells in the exercisers' legs, allowing them to 'take over' the burden of exercise (slow-twitch cells would be more efficient than fast twitchers at low intensities of exertion). However, Dr. Hugh Montgomery, lead scientist in the study, believes that another mechanism may be at work. Montgomery thinks that the long ACE genes may have profound metabolic effects within the muscle cells, in addition to their influence on artery walls. Basically, he suggests that the long genes may improve
167
SOCCER ARTICALS the efficiency of fuel selection, uptake, and utilization by muscle fibres during exercise, thus enhancing economy.
Of course, many will wonder whether Kenyan runners have the long-ACE genes (but probably won't speculate on how the Ethiopians were able to borrow those ACEs from the Kenyans, or how the Kenyans picked up the genes from the Finns, who borrowed them from the Brits, who took the alleles from earlier Finns, who got them from Swedes, etc.). Before this kind of thinking goes too far, however, we should point out that about 25 per cent of British and American citizens have double-long ACE genes, which in the case of Americans would mean that almost three times as many Americans hold double ACEs, compared to Kenyans, even if the entire Kenyan population had only the extended genes! It is clear that the research has implications which range beyond endurance exercise. Drugs called 'ACE inhibitors' help cardiac cells survive heart attacks and also improve survivorship in patients with heart troubles of various kinds by easing artery tightening and perhaps in part by letting nitric oxide do its thing and improving the efficiency of cardiac muscle-cell contractions. ACE inhibitors might also help increase the mechanical and metabolic efficiency of muscles in individuals who for various reasons are energy-deprived. The ACE work is exciting stuff, uncovering not only the genetic but also the important physiological foundations of exercise excellence. In our next issue, we'll provide you with a review of what scientists actually know about the genetic underpinnings of performance.
SOCCER ARTICALS | FOOT BALL
The ACE of hearts Before rushing out to your local exercise geneticist to find out if you have the long version of ACE, bear in mind this caveat, however: so far, the efficiency improvement has only been detected at very low exercise intensities; we don't know if it will hold true at competitive speeds, too.
Owen Anderson
Strength training Strength training reveals strange sex bias A new US study of the effects of strength training on inactive men and women has produced a fascinating and unexpected new finding: while training produced significant increases in resting metabolic rate in young and older men, it had no effect on the resting metabolism of women. The study involved 46 physically inactive subjects divided into the following four groups: young men (aged 20-30), young women, older men (65-75) and older women. After testing of various parameters, including aerobic capacity, body composition and resting metabolic rate (RMR), all the subjects took part in a whole body strength training (ST) programme for three days per week for an average of 24 weeks, using Keiser K-300 air-powered exercise equipment. They were then re-tested, with final
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Significant findings were as follows: a. Each of the four groups increase fat-free mass (FFM) significantly in response to training, with young subjects showing significantly greater increases than older ones, but no apparent gender differences. b. By contrast, changes in fat mass were affected by gender but not by age, with men showing a significant reduction and women no change. c. All groups showed significant increases in 1-M strength for all exercises, with changes for chest press and leg press analysed separately for any effects of age and gender. Combined young subjects increased 1-RM strength in the leg press more than older subjects (31% v 23%). Young subjects increase chest press 1-RM strength significantly more than older subjects (28% v 16%) and men increased significantly more than women. d. Significant increases in absolute RMR (9%) were observed for both young and older men but not for young and older women, despite similar increases in fat-free mass. e. There was no change in energy expenditure of physical activity (EEPA - the other major component of total energy expenditure apart from RMR) outside the ST sessions for any of the groups. 'The results of this study show for the first time that changes in RMR in response to ST is affected by gender and not by age,' the researchers report. 'Furthermore, when RMR was corrected for [fat-free mass] there was still a significant gender effect, with men having a ST-induced significant increase in RMR, whereas women still showed no change.' 'In addition, contrary to what has been suggested previously, ST does not cause an increase in EEPA outside of the training sessions in healthy, sedentary young and older men and women.' What can explain the clear gender difference in the impact of strength training on resting metabolic rate? One possible explanation advanced by the researchers is 'differences in sympathetic nervous system activity responses to ST', which was not, unfortunately, measured in the study. Med Sci Sports Exerc 2001 Apr 33(4) p32-41
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results available for seven young men and women, 10 older men and eight older women.
Isabel Walker
genetics and sports performance Genetics And Performance: What research tells us about African runners: are they really genetically more gifted? Page 1 2 African runners are genetically superior to white runners. Compared to whites, blacks are better suited for sports which involve short, explosive bursts of energy. Individuals from West Africa 'make' good sprinters, while people from East Africa are endurance
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Of course, believers in black 'super-genes' haven't been able to explain exactly how Africans have managed to corner the market on superior genetic material. When the Finns dominated the running world in the 1920s and again in the 1970s, no loud voices proclaimed that Finnish runners were genetically superior. Instead we pondered the merits of reindeer milk and called Lasse Viren a potential blood doper. When the Brits dominated middle-distance running in the 1950s and 1980s, there was no talk about brilliant British genetic material. Rather, we heard about British pluck and hard work. And when the Chinese women ran wild in 1993, it was because they were drugged, not because red-hot genetic material had fired up their performances. But now that Africans are running wild, the genetics lessons begin. Somehow, Providence has chosen to bless only African runners with top-quality DNA.. Opinions, not facts It's time for a reality check. Although beliefs about genetic differences between African and non-African runners are widely held, it's important to remember that these beliefs are opinions - and nothing more. There's simply no scientific evidence to support the idea that African runners are genetically superior to European, North American, Asian, or South American athletes.. Why isn't there any evidence? At present, we don't even know WHICH genes are necessary for topflight performances! Since we don't know which genes are important, it's impossible to measure the relative frequencies of performance-enhancing genes in different groups of athletes. In addition, as explained at the end of this article, the available scientific research suggests that genetic factors are less important than nongenetic factors (including training and lifestyle) in determining performances..
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Those are strong statements. Many people believe them. And implicit in the statements are two inferences that usually remain unstated: (1) If blacks are physically exceptional, then they don't have to go through the mental turmoil of constructing a rigorous training programme; they can just let their bodies work their magic. (2) Whites are at a disadvantage. Since they're handicapped by bad genes, and therefore by their anatomy and physiology, they will never be able to compete equally with Africans..
Still, when Mr. Gebrselassie of Ethiopia rips through the 5K in a world-record 12:44 or Mr. Kiptanui from Kenya slashes the 3000-metre steeplechase mark, the familiar refrain begins again: Africans have the most slender upper bodies, the thinnest bones, the most rail-thin calves, the most tent-like lungs and the most reservoir-like, elephantine hearts - all because they have the optimal genetic make-ups. As a result, we don't need to concern ourselves too much with how the Africans train, or how they think about running, or what motivates them to run far ahead of everyone else. It's enough to believe that they were born with a vast talent which places them head and shoulders above the pack.. Why? Now ask them how? Continuing to rely on the 'genetic explanation' for African superiority has negative consequences. After Africans win the vast majority of distance medals at the Atlanta
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SOCCER ARTICALS Olympics - as they inevitably will - and then return to their continent, anyone saying that they won their hardware because of their genes is giving a huge insult to their untiring work and relentless motivation. And summoning up the hocus-pocus of genetic differences makes the running community less eager to actually learn something useful from the top African runners. You've probably noticed that people aren't exactly beating down the Africans' doors in order to understand how to train, even though the Africans have blown the socks off runners from the rest of the world. Instead, we continue to 'learn' from the same old coaches and gurus who have worked with and trained runners considerably slower than the current crop of Africans..
What the research actually says There are just three relevant studies in the scientific literature that have examined physiological differences between Africans and non-Africans, and none of the three actually looked specifically at gene quality. That's no surprise; since, as mentioned, scientists don't actually know which genes code for endurance performance, they can't possibly determine whether Africans have a lockhold on superior genetic material. We don't know what 'superior genetic material' actually is.. So, instead of looking at actual genetic differences, scientists have made inferences about genes based on the physiological differences which they detect between blacks and whites. In a study carried out by Claude Bouchard and his group at Laval University in Quebec, 23 black male students and 23 Caucasian male students were compared. The black students hailed from Cameroon, Senegal, Zaire, the Ivory Coast and Burundi (mainly, that is, from the western and central parts of Africa), while the Caucasians were born in Canada and were of French descent. Both the Africans and Caucasians had an average age of 25, weighed about 154 pounds and were about 5'9' tall. All the students were sedentary at the time of the study..
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That's a bit strange. In the business world, we ask the top executives how they've managed to make their companies so successful. In the medical field, we ask the very best surgeons specific questions about their surgical techniques. But do we ask the Africans for training information? Why is it so much more convenient to believe that Africans have risen to the top because of inborn talent?
No gene frequencies were measured, but Bouchard found that both groups had the same percentage (about 18 percent) of type IIb muscle fibres - the cells which are critically important for sprinting (so much for the idea that western Africans have muscles uniquely suited for high-speed running!). There were two key differences in muscle composition between whites and blacks: Caucasians had a higher percentage of type I cells (41 vs. 33 percent), while Africans checked in with more type IIa muscles (49 vs. 42 percent). As you know, type I fibres are great for prolonged, moderatespeed endurance performance, as in an event like the marathon, while IIa cells promote faster running times in shorter events like the 5K.. Although Africans had more IIa cells and fewer type I cells, we can't say that these differences are genetically based. For one thing, studies show that muscle fibre type is not tightly regulated by genes. Also, an individual's muscle-fibre composition can change over time. IIb fibres can probably become IIa cells, and IIa cells may be able to become type I fibres. Thus, it's impossible to say that the blacks' higher frequency of
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SOCCER ARTICALS IIa fibres was a genetic thing.. The only other key difference between the Africans and Canadians was that blacks had higher concentrations of 'anaerobic' muscle enzymes, which are chemicals that spur the production of energy during short, intense running, whereas whites showed up with greater levels of 'aerobic' enzymes needed for continuous, endurance exercise. Again, there's no reason to conclude that these physiological differences are caused by genetic differences. The increased anaerobic-enzyme density in blacks might have simply been the result of their higher frequency of IIa cells..
What Tim Noakes found.. In a separate study carried out several years ago, Tim Noakes and his colleagues at the University of Capetown compared elite black vs. elite white South-African runners. Although both groups had similar 5-K times (about 13:45), the blacks were considerably faster in 10-K and half-marathon races. VO2max, running economy, maximal running velocity, training mileage and the percentage of type I muscle cells were exactly the same in the two groups, but there were some differences: (1) blacks ate more calories and carbohydrate per pound of body weight, compared to whites, (2) blacks trained considerably faster than whites, (3) blacks produced less lactate while running at race speeds, and (4) blacks were quite a bit shorter than whites (5'6' vs. 5'11') and weighed less (123 vs. 154 pounds)..
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The Laval scientists concluded that 'black individuals are, in terms of skeletal muscle characteristics, well endowed for sport events of short duration'. That's a somewhat shaky conclusion, since blacks and whites had exactly the same concentrations of IIb cells, the ones which are critical for sprinting, although it was true that blacks had higher amounts of anaerobic enzymes. As mentioned, it was impossible to say why the blacks' muscles were more tilted toward IIa fibres and away from type I cells. It might have been genetics, but it might have been the result of lifestyle, too..
Note that only point four can be firmly pinned to genetics. Body height - although influenced by the environment - is fairly strongly determined by genes, and body weight tends to follow from height. Eating more calories and carbohydrate (point 1) is a lifestyle factor. Running at higher training speeds (point 2) often is part of an overall training philosophy that emphasises intensity rather than volume and is not necessarily coupled with a particular genetic constitution. Producing less lactate while running at high velocities (point 3) might simply be a long-term result of the more intense training carried out by blacks. Overall, Noakes' work provided no solid evidence that blacks were genetically different from whites
genetics in sport
What research tells us about African runners: are they really genetically more gifted? Page 1 2
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SOCCER ARTICALS ...and Bengt Saltin The most revealing study on this topic was carried out by the renowned Swedish exercise physiologist, Bengt Saltin, who compared sedentary adolescent Kenyans, Kenyan high school runners and elite Kenyan runners with top-level Scandinavian runners. Saltin unearthed a number of important facts. First, relatively sedentary adolescent Kenyans had exactly the same aerobic capacities as sedentary Danish teenagers. If the Kenyans were really genetically superior, you would expect them to have higher VO2maxs than their Scandinavian counterparts (unless their 'superhuman' genes only revealed themselves in response to training).
Third, and following directly from point two, Kenyan runners - including the high schoolers - were more economical than the elite Scandinavians and also produced less lactate during high-speed running. This makes sense: one of the best ways to boost economy is to train fast, and the Kenyans have the corner on intense training. Also, fast training boosts the aerobic qualities of fast-twitch, type IIa muscle cells and lowers their lactate output, which probably explains why the Kenyans have lower lactate levels during strenuous running. Since high lactates are associated with fatigue, that's a very good thing! The fourth finding - a critical one for our discussion of whether the Kenyans have a genetic edge - was that sedentary adolescent Kenyans had VO2max readings of 47 (the same as Scandinavians), very active (but non-training) Kenyan teenagers had VO2maxs of about 62, and seriously training high school Kenyan runners checked in with average VO2maxs of 65 to 68. Senior elite Kenyan runners have had their VO2max levels measured at 75 to 85. This progression in aerobic capacities from the mid-40s to high70s and low-80s is exactly the same as the one observed in Americans (sedentary American youth have VO2max values in the 40s, while topflight runners like Salazar, Ryun, and Prefontaine were in the high 70s and low- to mid-80s). The progression in VO2max values is the same in Kenyans as it is in Americans! In addition, as high school Kenyans become elite senior runners, they increase their number of blood vessels per muscle cell and also enhance the concentrations of energy-producing aerobic enzymes inside their muscle cells. Those are natural responses to hard training and aren't necessarily caused by superior genes.
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Second, young Kenyan runners trained with astonishing intensity: About 50 to 60 percent of their total mileage was done at heart rates of 90 percent of maximum or higher! This was significantly higher than the Scandinavians' total and is much higher than anything European and American runners do generally.
Calling all Kalenjins Proponents of the genetic theory often point out that of the more than 35 tribal groups in Kenya, a single tribe - the Kalenjins - has produced most of the great runners (Lelei, Loroupe, Kiptanui, Keino, Kiprotich, Cheromei, Sang, Rono, etc.). The Kalenjins were traditionally a pastoral people who roamed the beautiful Rift Valley of Kenya with their cattle, so one might argue that genes which enhanced the ability to move long distances were 'selected' over evolutionary time. In contrast, members of another large Kenyan tribe, the Luo, have traditionally fished for a living and have produced few top runners.. However, political and social forces inside the country tend to favour the development
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So what's the real reason? If genes aren't responsible, what accounts for the difference between African and nonAfrican running? The African approach to training differs from the American-European method in a number of ways, including intensity (Africans usually train more intensely but with less mileage), the amount of hill training (there's no comparison here; the Africans are almost always working on hills), periodisation (Africans vary their training more - favouring big upswings and then gentle troughs; in fact, many Africans take a month or two away from running while their American and European peers continue to plug away without a break), and diet (Africans eat more carbohydrate, less protein, and less fat). Africans also benefit from a decade-long 'base' period - just running back and forth to junior school at moderate speeds - before they take up serious running, while Americans and Europeans tend to simply plunge into competition in more senior school without a prolonged, strength-boosting build-up.. Many of these factors have already been studied in scientific settings. We know that intensity is the most potent producer of fitness, yet American and European runners still preach the merits of high mileage. We know that hill training is better than flatground running, yet American and European runners often limit hill work to once a week. We know that the African diet is more conducive to elite performances, yet American and European runners continue to edge toward more protein and fat..
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of Kalenjins at the expense of other tribes. In spite of this, the recent trend in Kenyan running has been for non-Kalenjins (Ndeti, Kamau, Kinuthia, Masya, Osano, Asiago, Osoro, Karori, etc.) to become more prominent as time goes by, rather than for Kalenjins to increase their dominance. Most notably, the Kikuyu tribe, always a fine source of running talent (five-time world champion John Ngugi is Kikuyu), is beginning to produce more and more excellent runners, even though the Kikuyus have not interbred with Kalenjins and historically were not a nomadic people. In fact, running talent may be fairly equally distributed among Kenya's tribes. In other words, the Kalenjin-genetic hypothesis weakens once you take a closer look at what's really going on. How could so many different groups of non-interbreeding people produce top runners, if genetic factors were really the paramount factor?
In addition, our book on periodisation - how to structure training over rather prolonged periods of time in order to produce the best-possible performances - is still empty, or rather - it's filled with lots of theory and little hard data, so it's perhaps in this area that the Africans can be our pragmatic teachers. It's clear that the African pattern of very hard work followed by very thorough rest fits better with human physiology than the American and European scheme of hard work - and then more hard work. The human body always reaches optimal functioning more readily when stress is combined with recovery, rather than when stress is continuously kept at a taxing level.. The bottom line? Rather than speculating about superior genes, let's ask world champions like Mr. Tergat and Ms. Tulu what they are doing in January, March, July and September, and throughout the whole year. Chances are good that we'll pick up some useful information from them. Let's face it, there's no evidence that Africans have a lock on the genes needed for world-record running performances. After all, we don't even know what those genes are, and (as the following note explains) most research has
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SOCCER ARTICALS suggested that training and lifestyle - not genetic factors - account for more of the variation in athletic performances. So let's give the Africans credit for earning their world-beating performances. And let's learn from them about how to perform at the best-possible level.. Research footnote Could geneticists ever demonstrate convincingly that Kenyans are genetically superior? Of course! They would simply have to identify the genes which are important for endurance performance and show that those genes are more prevalent in Kenyan runners..
In the meantime, we might try to look at genetic differences indirectly - by examining physiological differences between Kenyans and non-Kenyans and then making inferences about genetics. For example, we might compare Kenyan and American fiveyear-olds, before either group has had a chance to do any training (even a smattering of training might make one group look better than the other). If we found no physiological differences, it would appear that the Kenyans did not enjoy an inherent genetic advantage.. However, even if the Kenyans were fitter, it would be hard to argue convincingly that the difference was genetic. After all, the Kenyan kids would probably eat differently than the Americans (fruits and vegetables versus Snickers bars), their everyday activity patterns would be different (Kenyans would gather wood and haul water while Americans would watch the box), and many of the Kenyan youngsters would probably be residing at altitude. All of these factors - diet, habitual activity and altitude residence - can have a strong impact on physiology, so the Kenyan kids' edge might have nothing to do with genetics..
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This can't be done at present. We simply don't know which genes are critical for enhancing performance, so we can't measure their frequencies in Kenyans, Americans, Slovenians, Siberians, or anyone else. Identification of such genes will probably happen, but not for another five to 10 years at least..
How about training previously sedentary groups of Kenyans and Americans of various ages and then observing their responses to training? Of course, we would try to make everything as similar as possible: Americans and Kenyans would have the same training history and be the same weight, height, age, etc. If the Kenyans improved by 30 percent in response to our training programme while the Americans went up by only 15 percent, wouldn't that show that Kenyans had special genes which boosted their responsiveness to training? Well, no. Again, the Kenyan difference might simply be due to prior lifestyle factors such as diet, altitude, daily activity, etc. The bottom line is that you can't look at Kenyan world-beating performances and say 'Aha! It's genetic!' Too many other factors can account for performance differences. As the great geneticist Claude Bouchard, Ph.D., says: 'There's currently no evidence that the Kenyans are genetically superior.' Owen Anderson
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Olympics Sex test Olympics Sex Test: Why the Olympic sex test is outmoded, unnecessary and even harmful. At the Olympic Games in Atlanta, about 3,500 women athletes had to undergo a diagnostic procedure that most medical authorities have characterised as misleading and unnecessary: a sex test aimed at verifying that they are not males masquerading as females. The aim, obviously, is to ensure that males, with their naturally androgenenhanced muscular strength, don't compete against females in women-only contests. But most medical experts say that the test is far more likely to bar unfairly from competition women with genetic abnormalities that confer no such advantages.
The only well-documented case of a male impostor competing against women in the modern Olympics involved a German athlete named Hermann Ratjen, who bound up his genitals, assumed the name 'Dora' and competed in the high jump in the 1936 Olympics. The deception wasn't discovered until 1955, when Ratjen, who came fourth in the event, blamed the deception on Nazi officials. Sex testing was introduced in competitive sports in the mid-1960s, amid rumour that some competitors in women's events were not truly female - especially two Soviet sisters who won gold medals at the 1960 and 1964 Olympics, and who abruptly retired when gender verification testing began. The first tests, at the European Championships in 1966 and the Pan-American Games in 1967, required female competitors to undress before a panel of doctors. Other methods used during this period included manual examination or close-up scrutiny of the athlete's genital region.
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Sex testing was hardly an issue in early Olympic Games when the competitors, all men, walked naked through the gates. But doubts about the gender of participants in women's events occasionally arose after the games were opened to women in 1912.
When athletes complained that these tests were degrading, the IOC at the Mexico City Olympics in 1968 introduced genetic testing in the form of a sex chromatin (Barr body) analysis of cells from a buccal smear. The procedure was further modified at the Barcelona games, using the polymerase chain reaction to amplify the DNA extracted from a specimen to allow detection of a Y chromosome gene, SRY, that codes for male determination. While this procedure was far less humiliating for competitors, geneticists and other experts argued that the test is pointless at best and has the potential for causing great psychological harm to women who, sometimes unknowingly, have certain disorders of sexual differentiation. Published data suggest that test results for about 1 in 500-600 athletes are abnormal and could result in their disqualification, says Dr James C. Puffer, of the University of California, Los Angeles, School of Medicine, who served as the chief medical officer for the 1968 US Olympic team.
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In Puffer's opinion, continuing to require gender verification is ill-advised because it is no longer needed to achieve its original purpose of detecting male impostors. Why? Because of the revealing, body-sculpting apparel worn by modern athletes. 'There's no way with today's spandex uniforms that someone would mistake a male masquerading as a female.' Athletes also know they are subject to doping tests, which require them to urinate under the watchful eye of an official (all winners are tested, as well as a random selection of other competitors). 'So, from a practical standpoint, it would seem that gender tests are totally unnecessary,' Puffer says. That was the conclusion reached by the IAAF when it abolished sex tests in 1992. (Journal of the American Medical Association, July 17, 1996, vol. 276, no. 3, pp. 177178)
Heredity, genes and sports performance
Heredity, Genes And Sports Performance: Dad, mum and you how much do your genes really influence your performances?
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According to Puffer, there are a number of disorders of sexual differentiation where an individual has a genetic make-up but is female for all intents and purposes. 'Each case is very complex,' he says, 'and needs to be handled with the utmost sensitivity because of the issues involved.' A case in point is the condition called androgen insensitivity syndrome (AIS) or testicular feminisation, which experts estimate affects about 1 in 500-600 female athletes. Although such individuals are genetically male because they have both an X and a Y chromosome, their tissues cannot respond to androgens and they develop as women. The irony is that the tests would not identify women with medical conditions that, in theory, might give them a competitive advantage over 'normal' women, such as congenital adrenal hyperplasia and androgen-secreting tumours that could result in greater muscle mass.
When Nick's friends asked him to take part in a casual Saturday afternoon game of soccer, he didn't realize that kicking a ball around on a muddy field would change his life. But as he chased after that damned ball, while his leg muscles cried out in pain and his lungs heaved like circus tents in a storm, Nick realized that his body had gone all to hell - after just a few short years of scoffing up thick slices of Yorkshire pudding and slugging down pints of ale each night after work. In the locker room after the game, Nick peered at his paunch, glared at his lardy shoulders, stole quick glances at his varicosed legs, and decided that maybe it was time to .... well .... do something. He wasn't sure exactly WHAT to do, and he wondered whether his preoccupation with his flabby belly was little more than bathos in the bathhouse, but gradually he developed a firm resolve to 'shape up'. By the next evening, he had purchased a nifty set of running shoes. And Nick was not the kind of fellow to do things by halves. Just as he had eaten, imbibed, and lazed around really earnestly over the years, he began his new, fitter life by training with the steadfastness of a monk. Flab fell from his abdomen, muscles burst from his buttocks, sinews sprouted from his thighs, and his lungs expanded and deflated in a more relaxed manner as he cruised through his daily runs.
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SOCCER ARTICALS Nick even began to enter races, and his 10-K times improved steadily. His first competition took 47 minutes, but soon he was at 46 minutes, then 45, made a big breakthrough to 42, and - after a year of hard training - broke the magical 40-minute barrier with a euphoric 39:55. Soon he was running in the 39s regularly, and he even surged through a sizzling 38:30 one beautiful autumn day.
Now, Nick had entertained thoughts of running 10 kilometres in 35 minutes, and - if the truth be told - he had even had a secret longing which grew stronger each time he set a new PB. His hope was that he might be one of the lucky ones - someone to watch out for at races, someone who could be an elite athlete and actually win prize money from the sport. Since all of those hopes were now dashed, Nick did the only thing he could do. He began to blame his mum and dad. Poor old mum, hobbling down the street to the market, and dad, puffing on his blasted pipe and reading the paper at the fireside, why hadn't they given him more of the right stuff? Why hadn't mum done more training as a schoolgirl, taken up marathon running as a young woman, set age-group records after menopause, and encouraged Nick to be more active? Why hadn't dad chucked away his god-awful pipe? Surely that foul device had clogged Nick' s lungs with smoke as a child, thwarting his aerobic development.
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What happened next? But then, sadly, the improvements in performance stopped. Nick waited, and trained, and raced, and waited some more, but when not a single additional second dropped from his race times, he began to fiddle with his training, added more speed work, carried out hill repetitions, took up weight training, bought books about Olympic athletes, and even went to Kenya on holiday in hopes of adding some East-African speed to his legs. The result? He continued to run his races in his usual 38s and 39s. Nick began to face the hard truth - that he just wasn't going to improve any further.
A chip off a bad block? Nick continued to resent his parents' poor influences for some time, but then one day at a race in London, Nick - for no apparent reason at all - decided to line up with the elite runners at the starting line. If he couldn't run a great 10K, he wanted to at least feel what it was like to rub shoulders with the great runners. As he stared at the slim bodies and determined faces next to him, he had a sudden realization: all of the parental training and coaching in the world would not have helped him. He was stuck in bad stock: his parents had simply not given him the genes of a Gebrselassie or a Kiptanui. In fact, Nick' s soul - the soul of a running fanatic - was trapped in the body of a greengrocer. Nick returned to the middle of the pack of runners with a horrible realization: great athletes are born - not made. But was he right? Is it true that the most important thing an aspiring athlete can do is to choose the right parents, as the great Swedish exercise physiologist Per-Olof Astrand once claimed? Actually, no. Although athletic performance is influenced by genetics, scientific
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SOCCER ARTICALS investigations have frequently found that it's even more dramatically shaped by training and motivation, not genes.
However, if genes are important, identical twins should respond in a very similar fashion. If one member of a set of twins boosts maximal aerobic capacity (V02max) by 35 per cent, for example, the other should also raise aerobic power by about 35 per cent. If one twin lifts V02max by 10 per cent, his identical twin should also get about a I O-per cent gain. If performance is highly 'heritable,' eg, it can be passed on readily in genetic material, we would expect that identical twins would almost always respond to training in the same way. On the other hand, if identical twins develop quite different performance capacities, it would be hard to argue that genes play a major role in determining the response to training. For example, if one twin gains 50 per cent and his identical twin increases aerobic capacity by only 10 per cent, we can figure that something other than genes is determining their performances. After all, their genes are identical, but their responses to training are quite different. One person in 50 has a twin Scientists interested in the genetics of performance are no slouches, so they usually include both 'monozygotic' and 'dizygotic' twins in their studies, as well as brothers and sisters. Somewhat surprisingly, it' s not hard to find twins for these studies. Although many people think that twinning is a fairly rare event, the truth is that about one out of every 100 births involves twins, which means that one person in 50 has a twin.
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Looking at identical twins Not surprisingly, many of these studies have focussed on what happens when twins embark on an exercise programme. The reason for using twins in the performance research is simple: if both twins and people plucked at random from the street begin a serious exercise programme, there will be a huge variation in response. Some individuals will improve their aerobic capacities by 50-60 per cent or more, others will achieve a more-usual gain of 20-30 per cent, and a few unfortunates will get an aerobic uptick of less than per cent.
About 33 per cent of all twin pairs are identical (monozygotic), which means that they originated from exactly the same sperm-egg combination and have precisely the same genotype (their genetic constitutions are identical). On the other hand dizygotic (fraternal) twins, although born at the same time, come from different sperm-egg combos and are no more closely related genetically than 'normal' siblings. Dizygotic twins, brothers, and sisters share about 50 per cent of the same genes. As a result, if genes really do determine performance, we wouldn't expect dizygotic twins and siblings to respond to training as identically as identical twins. However, fraternal twins and sibs should be more similar than people chosen at random from the overall population. To put it another way, monozygotic twins should have almost the same 10-K times, as long as their training is similar, dizygotic twins and siblings might have 10-K times a few minutes apart, and people chosen at random might have times ranging from 26:44 (the current world record) all the way up to 55-60 minutes. The less close the genetic relationship, the wider the variation.
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The research results So what have scientific studies actually found? Much of the best work has been carried out by Claude Bouchard, Ph.D., and his colleagues at Laval University in Quebec, Canada. In the early 1980s, Bouchard and co-workers decided to find out just how much variation in fitness could be present in a group of people who were training in a fairly similar manner. The goal was to eventually determine what portion of this variation was due to genetic factors and what portion was due to non-genetic influences such as nutrition, smoking habits, past exercise habits, age, socioeconomic status, etc. In one of the first studies, 24 similar, initially sedentary subjects trained in exactly the same manner for 20 weeks. Although the training was identical, the people responded to training in disparate ways. Although the average gain in V02max was 33 per cent, one individual had gained 88 per cent, while another had increased aerobic capacity by only 5 per, cent - with exactly the same training programme!
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Bear in mind, though, that we can't determine how much of any single person's performance is determined by genes, but we can assess how much of the VARIATION in performance within a group of people is attributable to genes. In other words, we can't tell Nick that, say, 40 per cent of his 10-K improvement from 47 to 38 minutes was the result of the DNA piloting his cells while the other 60 per cent resulted from his training, but we can estimate that 40 per cent of the variation in performance times in a population is due to genetic differences between members of the population. That's not very precise or individualised, but it does give us an indication of how important genes are in deciding what happens when people get serious about training. If 80 per cent of the variation was due to genetic factors, for example, we could sensibly conclude that the effects of genes far outweigh the effects of actual training.
Variation in actual performance, which was measured as the average power output a subject could sustain on a bicycle for 90 minutes, was also sizeable. Overall, performance soared by an average of 51 per cent after 20 weeks, and the biggest gainer was an individual who improved performance by 97 per cent, while the smallest improvement was made by a sad sack who advanced by just 16 per cent (less than 1 per cent per week). These and later findings taught the Laval scientists that there are 'responders' and 'non-responders' within any population of people. The 'responders' make big improvements in aerobic power and performance as a result of their training, while the non-responders barely emerge from their sedentary physiological states, even after 20 weeks of vigorous work. Exercise scientists reckon that about 5 per cent of people in the population at large are high responders (they can improve by over 60 per cent), while about the same per centage are low responders (they improve by less than 5 per cent). Are you a 'late bloomer'? The Laval researchers also found that the time scale of training responsiveness varies a
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SOCCER ARTICALS lot between people. Some are much better after just four to six weeks of training but may not improve after that, while others - the 'late bloomers' - are stagnant for six to 10 weeks and then really take off, improving their aerobic capacities by 20-25 per cent after 10 additional weeks of training.
Identical twins respond identically The most important finding, however, was that identical twins did in fact respond almost identically to the training programme. For example, one twin upgraded V02max by 10 per cent, while his identical twin improved by 11 per cent. Another gained 16 per cent while his twin settled for 14 per cent. Yet a third pair rested at 25 and 22 per cent. Overall, most of the variation in V02max was between, not within, sets of twins. However, this does NOT mean that genetics are the most important factor which determines performance. All the twin studies demonstrate is that genes are important; they do influence the way people respond to training. They don' t tell us that genes are more important than training and other factors. We only know that genes do play some role and that identical twins will be more alike than dizygotic twins and siblings, who in turn will be more alike than non- ' related people. That's hardly earth-shaking news.
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How significant are genes in determining responsiveness and in deciding if you're a responder, a non-responder, a quick responder, or a late bloomer? To check that out, the Laval investigators placed 10 pairs of monozygotic (identical) twins on a 20-week training programme. The 20 subjects trained four to five times a week, 40-45 minutes per session, with average training intensity set at about 80 per cent of maximal heart rate. After 20 weeks, aerobic power burgeoned by 14 per cent, and 'ventilatory threshold' ;L - the exercise intensity at which breathing rate begins to increase fairly dramatically - improved by 17 per cent.
And, in fact the twin research offers some 'twists' which suggest that genes play a 'supporting' - but not 'lead' - role on the performance stage. For example, 82 per cent of the variation in V02max in the Laval twin study was due to genetic differences, but only 33 per cent of the difference in ventilatory threshold was attributable to genes. Somehow, genes were playing a strong role in setting aerobic capacity, but the environment (lifestyle factors and past differences in training) was considerably more important in fixing ventilatory threshold. That' s a key finding, since ventilatory threshold - and a closely related variable called lactate threshold - are often found to be the best predictors of actual endurance performance, better than aerobic capacity, anaerobic power, or efficiency of movement. Married couples are equally similar And there are other findings which put a dent in the idea that genes are paramount in shaping performance capability. For example, the Laval researchers found that spouses were as similar in their response to training as were brothers and sisters, even though the spouses were totally unrelated genetically. In other words, if Joe and Jean are married and begin training with Joe's brother John, Joe's gain in V02max is just as likely to be the same as Jean'.s as it is the same as John's! That' s hardly a ringing endorsement of the idea that genes play the crucial role in determining performance.
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SOCCER ARTICALS In general, studies carried out with brothers and sisters suggest that genes explain only 20 per cent of the variation in observed performances. Training and lifestyle account for the other 80 per cent - or four times as much! In addition, investigations which put mothers and their children on a training schedule have found that genetics explain just 28 per cent of the variation in V02max, even though a mum and her offspring share about 50 per cent of the same genes. That means that 72 per cent of the variation is due to training and other factors.
Why mother is best Again, these findings hardly support the idea that great athletes are born, not made. But let's digress for a moment and consider why your mum is more important than your dad in determining how you'll turn out as an endurance athlete. The answer to this question rests inside tiny structures inside muscle cells called mitochondria, which provide most of the energy required for your endurance performances. The little mitochondria have their own genes, and all of the mitochondria in your body come from your mother, not from your dad, because your mum's egg contained mitochondria, while your father's penetrating sperm was mitochondria-free. As your foetal cells divided and formed muscle, nerve, and bone cells, they took with them mum's mitochondria. If she gave you good little mitochondria, you have a decent chance of becoming an endurance athlete; dad's mitochondria just don't count. As you've guessed by now, genetics don't play the dominant role in producing top-level performances, but in addition to mother's mitochondria, there are some anatomical and physiological attributes which are highly heritable - and which can help you get to the finish line of a race more quickly. For example, your heart's 'coronary network' (the distribution and size of blood vessels within your heart) is genetically determined, as is the branching pattern of blood vessels which lead into your lungs. Total heart size is mildly heritable, and the volume of the heart's left ventricle - the key internal chamber which sends blood to your muscles - may be strongly determined by genes.
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Sorry, dads, but the news is even worse for you. Investigations of fathers and their children have been unable to suggest that genetics plays any role at all in explaining variation in aerobic capacity, even though dad and son/daughter are 50-per cent alike! In other words, a father and his son are no more likely to respond to training in a similar manner than are two people selected at random on the street.
Muscle proteins, including key energy-producing enzymes, are also dictated by genes, as is muscle-fibre composition. If your mother and father had a high percentage of Type I muscle cells (the kind which have excellent aerobic potentials and promote superior endurance), your legs will probably also be biassed toward Type I cells, and you'll probably be a pretty decent marathoner. In fact, some studies have shown that muscle composition - or more specifically, the percentage of Type I fibres - can explain up to 90 per cent of the variation in race times observed during the 26.2-mile race. Metabolism of fat is also at least partially genetically determined. However, the bottom line is that your genetic endowment is really just the stage upon which your training, nutrition, and motivation act out their important roles and produce your ultimate performances. Even mum's mitochondria and the genes which
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SOCCER ARTICALS control heart size, muscle composition, and fat metabolism are only up to explaining about 30 per cent of the variation in performances in Great Britain, the United States, Timbuktu, and any where else. The rest of the variation - about 70 per cent - is due to the environment, e.g., training and lifestyle factors.
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So, the next time you line up at the start of a race, remember that genes have indeed played a role in determining how long it will take you to get to the finish line but that your training and nutritional practices have had an even larger impact! That's good news, because it means that your destiny as an endurance athlete is to a great extent under your own control.
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