[FREE COPY] The Performance Digest - Issue 40 (February 20) by Science for Sport

THE

February 2020 | Issue #40

PERFORMANCE DIGEST

A review of the latest sports performance research

How to Read Me! This guide shows you how to read the Performance Digest

Page Number

Section

Link to Abstract Review Title

Study Details

Practical Takeaways from study

Related links to learn more about the topic

Reviewers comments on the study

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Contents Click a topic to jump straight there

06 Reviewers

The brains behind the brilliance

07 Audio Review

A topic recap on all the research reviewed

08 The Science of Coaching The doctors diagnosis

09 Strength & Conditioning Performance-enhancing science

13 Technology & Monitoring

The tech revolution

17 Fatigue & Recovery You canâ&#x20AC;&#x2122;t adapt without recovery

21 Youth Development Their future is in our hands

25 Nutrition

You are what you eat

29 Injury Prevention & Rehab Minimising injury and maximising recovery

33 Self-Development Learn. Coach. Reflect. Repeat.

34 Offers

Exclusive, members-only discounts

Last month in the

Here is last month’s most popular discussions inside the Coaches Club...

Myles was wondering if any other coaches could help him with mapping out individual player profiles using GPS data. I think it’s safe to say that the group did not disappoint with this one! Lots of coaches helped him out with theirs approaches and kept nothing a secret.

Khyl is setting up his first-ever brand new

Matt got an amazing post going

S&C facility and

regarding building a huge list of

therefore had plenty of

fun S&C games you can use

common questions he was hoping to get some

with your athletes. Whether it’s

great feedback on.

simply ice-breakers or speed

Within the group, there’s a great mixture

and agility games, this list—

of those who work in

created by all the coaches in the

professional vs. those in

Coaches Club—had it all!

the private sector, and both were able to offer a tonne of excellent feedback to put his nerves at ease.

Check out all of these discussion and more...

Join the conversation Click here to get involved

Research Reviewers Dr. Will Vickery PhD Chief Editor

Dr. Francisco Tavares PhD CSCS ASCA L2 Fatigue & Recovery

Will is a Lecturer of Sport Coaching at Deakin University, Australia. Prior to

Francisco is the performance coordinator for Sporting Lisbon and has

this he has worked with Cricket NSW and Cricket Australia in an array of

previously worked as a S&C coach in elite ruby with the Chiefs Super

roles ranging from a sport scientist, development coach and a strength and conditioning coach. He completed his PhD at the University of Newcastle, Australia within the area of practice design.

Adam Kerr MSc ASCC The Science of Coaching

Rugby franchise and the PRO14 team, Glasgow Warriors. He holds a PhD from Waikato University and is a published author.

Tom Green MSc UKAD Advisor Youth Development

Adam is the Academy Performance Support Manager at Leeds United FC, and

Tom is the Head of Athletic Development at St Peters RC High School.

has previously worked at Middlesbrough FC, Arsenal FC, Scunthorpe United FC

He holds a Masters in S&C and has previously worked with West

and the Professional Golfers Association. He holds a Masters degree in Sport Science from Sheffield Hallam University and is an accredited strength and conditioning coach with the UKSCA.

James de Lacey MSc

Strength & Conditioning

James is currently the Head Strength & Conditioning Coach for the Romanian Rugby Union. He has previously worked in America's professional rugby competition Major League Rugby with Austin Elite and the NZ Womenâ&#x20AC;&#x2122;s National

Bromwich Albion FC, Gloucester Rugby club, and Great Britain Equine. Tom is our youth research reviewer at Science for Sport.

Dr. James Morehen PhD

Nutrition

James is a Performance Nutritionist for the English Football Association and works alongside the England national teams (men's

Rugby League Team. He is a published author and has completed a MSc in Sport

and women's). He is also a SENr registered performance nutritionist

& Exercise Science from AUT, Auckland, NZ.

and holds a PhD from Liverpool John Moores University.

Cody Roberts MSE Technology & Monitoring

Cody is a strength and conditioning coach and adjunct lecturer at the University of Iowa. He has an MSE in Exercise Science from the University of Kansas and also holds a CSCS from the NSCA.

Dr. Jordan August DPT, CSFC, SFMA, FMS Injury Prevention & Rehab

Jordan is a Physical Therapist and Strength Coach who currently practices in a Sports & Orthopedic clinic in Bergen County, New Jersey. He is passionate about educating athletes on ways to optimize performance while decreasing the risk of injury.

Save time and stay up-to-date without breaking the bank! Gone are the days of frustration, pouring though Google for hours trying to find relevant research. You can now access over 600+Â relevant, clear and concise research reviews spread over 40+ issues of The Performance Digest that you're reading now...

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Audio

REVIEW Internships and Careers in S&C A recap on what we know and hope to find out from future research with Tom Green.

WHAT WE DICUSS

In this episode of the “Audio Review”, Tom discusses internships and careers in S&C.

In this episode, you will learn: 

Important terms surrounding internships.



The daily struggles of interns.



What potential employers want and are looking for.



The role of a mentor.



Considerations on how to get a S&C job.

A bit about Tom Tom is the Head of Athletic Development at St Peters RC High School. He holds a Masters in S&C and has previously worked with West Bromwich Albion FC, Gloucester Rugby club, and Great Britain Equine. Tom is our youth research reviewer at Science for Sport.

Episode length = 39 min

Listen Now

The Science of

COACHING [Abstract]

Identifying athlete leaders What are the behaviours of high-quality leaders?

INTRODUCTION

WHAT THEY FOUND

WHAT THIS MEANS

Good leaders are seen as being vital to performance particularly within team sports, with the presence of good athlete leaders and associated with fellow team members feeling a stronger connection to the team, having more motivation, and a greater sense of the team’s ability. As a result of this knowledge, coaches are keen to know which individuals on their team show the desired characteristics and behaviours of leaders, to allow them to form leadership groups that can help create a positive impact on the teams sporting performance.

This study was completed in two parts, with study 1 including 392 players across 32 teams from soccer, volleyball, basketball, and handball (males: n = 188, females: n =204; mean age = 23.6 yr; mean years of experience in their sport = 14.6 yr) and study 2 consisting of 384 players, with an equal split between male and females (mean age = 23.9 yr; mean years of experience in their sport = 14.9 yr). The athletes in both studies were asked to fill out a questionnaire at the end of the season, which assessed the leadership quality of all their team members, across four leadership roles (task, motivational, social and external leader). Study’s 1 and 2 included different questionnaires, however, they both measured personality traits and behaviours to allow for direct comparison between the studies.

Athlete leaders in teams can be selected based of both personality traits and learned behaviours, it also highlights that high-level leaders can be taught skills to help them in their leadership roles, or to help assign new athletes in to roles in which they are more likely to succeed.

Although the personality traits of extraversion and being articulate were found to be important predictors of high-quality athlete leaders, it was mainly the leadership behaviours that were the best at highlighting which athlete leaders were of the best quality. Some of the leadership behaviours highlighted included promoting team-work and being an appropriate role model. It was also found that being prototypical (i.e. giving strong identity) for the group, by their identity entrepreneurships (i.e. ability to cultivate a shared team identity), and their identity impresarioship behaviour (i.e. ability to secure material outcomes like resources, support or recognition) were also behaviours that high-quality leaders perceived in themselves. In addition, a successful athlete leader was viewed as someone that could be trusted and respected by other team members, highlighting good practice of getting players to help with the selection of the athlete leaders within the team.

To conclude, teaching athletes how to engage with the other members of their team to create, embody, advance and embed a sense of belonging, will help those athletes to feel like better leaders themselves and will also help to drive the success of the team.

Previous research has looked at leadership identification from the focus of personality traits or behaviours. The results of previous work which has focused on the 'trait approach' proposed the idea that leadership is more ingrained into the innate characteristics of people (see HERE). On the other hand, research relating to the behaviours of individuals takes the viewpoint that leadership is more of a learned skill (see HERE). This research looked at the integration and contrast of diﬀerent leadership theories, to understand what the ideal athlete leader looks like, across all the diﬀerent leadership roles that athletes can assume.

It can also be suggested that athlete leaders are not just born with innate personality traits that make them more suited to their role than other athletes, but that the behaviours can actually be taught to allow athletes to thrive in such roles. The findings here align with previous research that suggests only 30% of the variance in leadership occupancy are accounted for by genetic factors, the rest are behaviours that can be learned and enhanced (see HERE).

Practical Takeaways ⇒

When trying to form leadership groups within sports teams, it would be beneficial to profile the personality traits and leadership behaviours of the athletes, so they can be channelled to the most suitable leadership roles.



Coaches should identify if any leaders within their team are not



Coaches should invest time in developing the leadership qualities of the athletes in their teams, as they are mostly learned behaviours. Developing players awareness of how they are viewed in the dressing room, identifying the skills that will give the players a sense of belonging, and ensuring they are role-modelling the types of behaviour wanted are all ways to develop these leadership qualities.

respected by their team mates, regardless of the personality traits and leaderships behaviours shown, as their potential to lead effectively is severely compromised when there is a lack of respect from their peers (see HERE).

Adam Kerr Adam is the Academy Performance Support Manager at Leeds United FC, and has previously worked at Middlesbrough FC, Arsenal FC, Scunthorpe United FC and the Professional Golfers Association. He holds a Masters degree in Sport Science from Sheﬃeld Hallam University and is an accredited strength and conditioning coach with the UKSCA.

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Strength & Conditioning

Strength & Conditioning This month’s top research in strength & conditioning.

HOW SHOULD WE INDIVIDUALISE SPRINT

PROGRAMS BASED ON HORIZONTAL FORCEVELOCITY PROFILES? Hicks, D. S. et al. (2019) Strength and Conditioning Journal. IS FLEXIBILITY AS IMPORTANT FOR SPORT AS WE ORIGINALLY THOUGHT? Nuzzo, J. L. et al. (2019) Sports Medicine. SHOULD WE FOCUS ON UNILATERAL OR BILATERAL EXERCISE FOR SPORT PERFORMANCE? Appleby, B. B. et al. (2020) The Journal of Strength and Conditioning Research.

Strength & Conditioning

[Abstract]

How should we individualise sprint programs based on horizontal force-velocity profiles? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

If a resistance training program is designed to enhance sprint acceleration, there are a two questions which need to be considered,

The practical recommendations in this review could be used to address F-V characteristics and horizontal force application and devise individual training programs for team -sports and individual sport athletes. A horizontal F-V profile gives these important variables:

Biomechanical determinants of sprint acceleration

1. 2.

Should coaches select exercises which focus on force, velocity, or power? Should exercise be selected that move in the horizontal or vertical direction?

Sprint profiling helps coaches understand the force-velocity (F-V) relationship relationship, which when used effectively, can, be used to individualise a training program to target an athlete’s mechanical strengths and weaknesses. This review provided information on the F-V relationship, the determinants and biomechanics of acceleration performance, and sprint profiling, as well as, discussing exercise selection and training programs for improving athletes’ mechanical effectiveness during sprinting.



Theoretical maximum velocity (V0) – maximal velocity



Maximal power (Pmax) – maximal power produced in the horizontal direction.

Horizontal force-velocity profiling

Ratio of forces (RF) – horizontal component of the



Ratio of decreases in force (Drf) – how force orientation changes from horizontal to vertical with increasing velocity .

⇒

Directing the resultant GRF in a more horizontal direction is more important during the acceleration phase when compared with the overall magnitude of force applied to the ground.

These variables usually are calculated from force plates, radar system, or the MySprint app.

Practical Takeaways Force production at low-velocity example Day 1 – Horizontal emphasis: Resisted sprinting 10 m 2x4 (load that restricts <30% of maximal velocity); Prowler march 2x20-, 30-, 40 m @ 120% BW; Hip thrust 5x5 @ 82.5% 1RM. Day 2 – Vertical emphasis: Clean pull 4x2 @ 82.5% 1RM; Back squat 3x5 @ 87.5% 1RM; Mid-thigh pull 3x5 @ 110% of clean.

F-V relationship defines the changes in propulsive force and horizontal power when running velocity increases.

GRF vector as a percentage of total GRF.



This is maintained across the duration of the sprint acceleration as velocity was increasing and ground contact decreasing, which is critical to performance.

until which force can be produced.



Faster sprinters are able to produce greater net horizontal impulse compared with sub-elite sprinters.



Theoretical maximum force (F0) – maximal force at null velocity.



RF identifies the technical ability of an athlete to orientate force horizontally while accelerating.



If total force is the same between athletes, RF can identify mechanical differences to be targeted with training interventions.

James’ Comments “After talking with one of the authors, this seems to be the best way to group your athletes. 1.

Rank your athletes by RF.

Look at the top and bottom third of athletes as “velocity” and “force” groups, respectively. The middle portion can be "optimal load" group.

Athlete’s with lower RF lack the ability to orientate force horizontally, so should have horizontal force emphasised (force production at low-velocity example).

Athletes with higher RF generally (based on my own experience) have a more negative Drf, which means the athlete cannot sustain it as velocity increases, and force at high velocity should be emphasised.

Some athlete’s may show much greater values across the board in the F-V profile. These athletes programs can contain a mix of qualities.”

Force production at high-velocity example Day 1 – Horizontal emphasis: Assisted sprinting 1x20-, 30-, 40 m @ 101% of training maximal velocity; Maximal sprint 3x20 m fly with 20 m acceleration; Bounding 3x8 contacts. Day 2 – Vertical emphasis: Hurdle Hops 3x5 contacts; Band assisted jump 2x5 @ 30% BW de-load; Depth jump to box 2x6.

Force production at maximal power (optimal load) example Day 1 – Horizontal emphasis: Maximal sprinting 3x10 m fly with 20 m acceleration; Resisted sprinting 2x10, 20, 30 m @ individual Pmax; Hip thrust 3x5 @ individual Pmax. Day 2 – Vertical emphasis: Power snatch 4x3 @ 30-50% 1RM; Power clean 4x3 @ 70-80% 1RM; Trap bar jump 5x3 @ 20-50% 1RM.

Want to learn more? Then check these out...

Strength & Conditioning

[Abstract]

Is flexibility as important for sport as we originally thought? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

There are two types of flexibility:

Historically, flexibility has been measured in a clinical setting in humans since the early 1900s. One of the first papers on flexibility in 1941 described stretches that were designed to improve flexibility and compared flexibility in different groups (runners and swimmers). This paper gave credence to the idea of flexibility becoming a component of physical fitness, due to linking the relationship between greater trunk, ankle, and shoulder flexibility to greater speed and endurance.

The key points from this article were:

⇒



Static flexibility, which refers to joint range of motion (ROM) in relaxed muscle. This is subjective, as limit ROM is determined by the tester or patient and their stretch tolerance. Dynamic flexibility, which refers to stiffness of the muscle-tendon unit within normal ROM. This is objective, as it’s assessed with force sensors and isokinetic dynamometers.

This paper is concerned with static flexibility, and specifically, the sit-and-reach test. The notion that flexibility is important for physical fitness has led to the idea that stretching be prescribed to improve ROM. However, flexibility can be maintained or improved by other exercise modalities that cause more health benefits.

Throughout the 1950s and 60s, flexibility gained popularity as an important part of athletic training due to the creation of the sit-and-reach test, as well as flexibility becoming a major part in school fitness testing programs. In the 1980s, flexibility was called “a major component of physical fitness” and claims were made about the health benefits of flexibility (see HERE). As a result of this historical perspective, flexibility is today conceptualised as part of physical fitness.

This opinion paper proposed flexibility be retired as a major component of physical fitness, as it has little predictive or concurrent validity with health and performance outcomes, and that static stretching does not clearly and consistently improve health and function.

Practical Takeaways 



While flexibility is being argued to be removed as a component of fitness, average ROM is likely still important for most sports. However, stretching to improve flexibility is likely not the most effective way to achieve, as performing any activity is likely to aid in flexibility. If extra ROM is needed (e.g. ice hockey goalies, swimmers), strength training is likely the best method to solidifying this. Here, we are looking at “strength at length” vs. passive flexibility. In this case, improving or maintaining ROM could be a simple as these examples: 

Hip flexor/quads – Long duration split squat isometric 1x1-5 min.



Hamstring – Romanian deadlifts with tempo eccentric (e.g. 3x5 w/ 4010 tempo).



Hip external rotators – Seated figure 4 with plate on knee isometric 1x1-5 min.



Adductors – Side lying half butterfly with plate 1x10.



Calves – Standing/seated calf raises w/ 3 sec pause at bottom 3x10.



Pec/shoulder region – Cable/dumbbell flys with pause at stretch 3x10 w/ 10 sec pause after last rep.



Lats – Meadows lat “stretch” (see HERE) or DB Pullovers 3x10.



Biceps – Incline dumbbell curls with pause 3x10 w/ 10 sec pause after last rep.



Triceps – Overhead triceps extension with pause 3x10 w/ 10 sec pause after last rep.

Want to learn more? Then check these out...

⇒

   

The sit-and-reach test doesn’t predict future incidence of low-back pain or injury in adults, hamstring injuries in male soccer or Australian football players, or lower-limb pain in adolescents. High levels of flexibility may increase injury risk. Absence of correlations between flexibility and other fitness components indicates that flexibility is a distinct trait, but not particularly important for health and function. Sit-and-reach test scores do not correlate with tactical performance tasks. In many athletic groups, flexibility levels often are the same as in controls, they do not correlate with athletic performance, and do not differentiate athletes of different playing abilities (e.g. similar sit-and-reach scores between starters and non-starters in American football and elite and sub-elite sprinters).

James’ Comments “If you’re like me, you often find stretching boring and don’t see any real change in long lasting ROM. The common thing you’ll find with the above “mobility” exercises are the use of load. In order to cement new ROM, there has to be strength in that range. I have used all of the above exercise examples and by far my favourites are the long duration isometric split squat and Meadows lat “stretch.” The ISO split squat, done before training, helps with any knee pain quickly and opens up the front of the hips. The Meadows lat exercise is perfect at the end of training and will have your shoulders feeling amazing in no time.”

Strength & Conditioning

[Abstract]

Should we focus on unilateral or bilateral exercise for sport performance? OBJECTIVE

WHAT THEY DID

Key phases of athletic performance generally occur on one leg (e.g. sprinting, change of direction (COD)). Hence, unilateral resistance training is perceived to offer greater movement specificity than bilateral exercises. The barbell step-up is an exercise where the majority of the movement is entirely unilateral, unlike other unilateral exercises (split squat).

Thirty-three state rugby union academy and The key findings of the study include: grade club competition players (age = 22.4 ± ⇒ BIL and UNI groups exhibited 4.1 yr) completed a six-week familiarisation, meaningful improvements in 1RM eight-week training intervention, and threestrength of squat and step-up, week maintenance phase. They were split respectively. into three groups, bilateral (BIL), unilateral  Difference in squat strength and eight(UNI), and control (CON). The intervention was performed during the pre-season, where week intervention was unclear with a the only difference between groups was the small difference in 1RM step up for the use of the squat (BIL) or step-up (UNI). UNI group. Volume-load was equated between groups.  Both BIL and UNI groups showed meaningful improvements in speed and Testing was performed before and after the COD. eight-week intervention and after the three-

Little research has examined the application of the step-up to improvements in sprint and COD performance. Therefore, the aim of this study was to examine the changes in sprint acceleration and COD ability as a result of resistance training using either bilateral or unilateral only.

week maintenance phase. These tests were 20 m sprint (5-, 10-, 20 m splits + 15 m fly), 50° COD test, squat and step-up 1RM with 90° knee angle.

Practical Takeaways 

In the podcast below, Cam Josse explains a simple periodisation strategy for programming unilateral and bilateral exercise. He states “I’m looking at a progression where we start with a foundation of coordination (single leg/more degrees of freedom) and we transfer that into really high outputs (bilateral training).” In this case, a pre-season training period could look like this in regards to main lower-body lifts: 

Block 1: Loaded Bulgarian split squat isometrics 3x30 sec/leg.



Block 2: Slow eccentric Bulgarian split squats (3-4 sec down) 3x4-6/leg.



Block 3: Fast eccentric or normal tempo Bulgarian split squats 3x4-6/leg.



Block 4: Back squats 3-4x3-6.



Throughout the unilateral blocks, small doses of bilateral exercise can be used (e.g. RDL).



Throughout the bilateral blocks, small doses of unilateral exercise can be used (e.g. stepup, lateral lunge).

Want to learn more? Then check these out...

WHAT THEY FOUND

 Difference between BIL and UNI in speed was unclear.

 BIL showed a greater improvement in COD than UNI group.

James’ Comments “Many S&C programs have a heavy emphasis on bilateral exercise all year round (e.g. squat, clean, deadlift). However, unilateral exercise in my opinion - is just as important. I have personally used exclusively unilateral lifts as my main lower- body lift in rugby backs and, we still managed to improve the speed and strength of all the players throughout the preseason. What is important if taking this approach, is being able to select exercise variations that allow for large loads, whether that’s bilateral or unilateral. For example, step-ups on a low plate or split squat off of high pins.”

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Technology & Monitoring

Technology & Monitoring This month’s top research on technology and monitoring.

WHAT VARIABLES BEST REPRESENT

FATIGUE WITHIN SOCCER? Hader, K. et al. (2019) Sports Medicine — Open. DOES TENSIOMYOGRAPHY PREDICT SPRINT AND JUMP PERFORMANCE? Pereira, L. A. et al. (2020) International Journal of Sports Physiology and Performance. IS THE PUSH BAND V2.0 A VIABLE VELOCITY-BASED MEASUREMENT OPTION? Hughes, L. J. et al. (2019) Journal of Strength and Conditioning Research. .

Technology & Monitoring

[Abstract]

What variables best represent fatigue within soccer? OBJECTIVE

WHAT THEY DID

The use of tracking technology allows for the monitoring of players’ external load variables during soccer training and matchplay, with hopes to individualise training, minimise injury, and optimise performance for subsequent bouts. However, there is lack of agreement regarding which specific external load metrics are most sensitive and best represent post-soccer-match fatigue.

Eleven studies (2011-2018), including 165 The primary findings of this systematic male soccer players (89% elite level) were review and meta-analysis included: used for analysis that specifically looked at soccer match locomotor-related metrics and  Match-related running distance above 5.5 m∙s-1 was the only variable that relationship to post-match internal strongly correlated with both responses (e.g. biochemical, neuromuscular, biochemical (i.e. creatine kinase levels) or perceptual measures). and neuromuscular (i.e. counter movement jump peak power output) Studies were assessed for methodological markers 3- and 24 h, but not at 48- or 72 quality and examined for consistency related h post-match. to external load metrics (e.g. distances

The aim of this review was to identify the most effective monitoring variables reflecting post-match acute and residual fatigue-related markers.

covered at different speeds, changes of direction, and forces experienced) and pooled correlation to biochemical markers (e.g. creatine kinase), neuromuscular performance (e.g. countermovement vertical jump), and perceptual measures within 3-, 24 -, 48-, and 72 h post-match. The quality and strength of the findings were evaluated to identify levels of evidence for correlated and representative variables.

Practical Takeaways 

It is imperative that an athlete gradually prepare for the mechanical stresses experienced in match-play which can be achieved not only by using small-sided games, but also with the specific prescription of sprinting or change of direction drills (see HERE).



Reinforce quality with sprint work, where repetitions should be performed with maximum effort and full recovery (see HERE), allowing sometimes 4-5 min between multiple efforts, replicating the volumes experienced in a soccer-match.



Modify the frequency and volume of work when preparing for competition (e.g. micro-dosing). This will allow for a greater work capacity across the week, recovery from exercise, and the acquisition of sprinting performance.



Prescribing high-quality (i.e. max effort and full recovery) and technically-focused acceleration work (see HERE) at the end of a warm-up not only increases workload and preparation, but helps to improve performance ability.



Prescribing sprints for 30-60 m is important for athletes to experience maximum velocity, as these distances and speeds are limited with small-sided games and exposure to this stimulus is important.

Want to learn more? Then check these out...

WHAT THEY FOUND

 There was no evidence of any

significant relationship with total distance covered and fatigue markers.

 There was little relationship between subjective (e.g. perceived recovery, stress, or mood) and objective measures (e.g. biochemical or neuromuscular).

Cody’s Comments “This systematic review and meta-analysis helps to clear the fog of the countless variables that can be reviewed with the help of today’s various tracking technologies. The most successful sport teams are ones that can keep their best players healthy and operating at their maximum potential, with specific reference to neuromuscular function. The results showcase the importance of monitoring the most stressful activities (i.e. high-speed running and change of direction) over the extensive high workload that can be experienced during 90 min of matchplay. It is during these stressful activities that injuries are most likely to occur, as well as the fact, that most scoring opportunities are associated with higher speeds. During times of condensed competition, high-speed running may impact readiness in the shortterm (24 h), but numerous variables (e.g. sleep, nutrition, stress) impact recovery rates in the 48 h and beyond post-match. Monitoring high-speed running distance is important, but don’t lose sight of the bigger picture with regards to recovery across the week.”

Technology & Monitoring

[Abstract]

Does tensiomyography predict sprint and jump performance? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Fatigue impacts muscular function, modifying mechanics and time-related parameters (e.g. contraction time). Tensiomyography (TMG) is a diagnostic tool that can measure a muscle’s contractile properties (i.e. displacement, contraction time, and delay time) in response to an external electrical stimulus.

Fourteen members of Brazil’s male national rugby union team participated in four different training sessions (e.g. strength, plyometric, sprint, and technical workouts (e.g. sport-specific drills or tactical rehearsal), separated by at least 48 h and performed in randomised order.

The primary findings in this study include:

The aim of this study was to assess TMG’s sensitivity in detecting acute fatigue related to vertical jump and sprint performances induced by four different exercise protocols (i.e. strength, plyometric, sprint, and technical sessions).

TMG of the dominant leg’s rectus femoris and biceps femoris was taken immediately before and after each session, specifically focusing on “velocity of contraction” (VC), derived from the muscle’s displacement and time of contraction after stimulation. This was in addition to squat and countermovement jump height, and 30-m sprint velocity. The changes in performance measures were analysed relative to the specific workout performed, as well as the relationship between VC, jump height, and sprint speed.

Practical Takeaways 

TMG is a passive and non-invasive monitoring tool that can help showcase the readiness of an athlete by providing an objective measurement of the neuromechanical properties of the primary muscles involved in speed and power sports.



TMG is a helpful diagnostic tool that can be paired with an athlete’s subjective report with regards to soreness or fatigue, in showcasing recovery from previous training or competition, optimising the progress for a return-to-play protocol after injury, as well as identifying an asymmetry between limb muscle function.



If a muscle is reading stiff and or slow to contract prior to training, prescribing a restorative or low intensive technical session that helps to increase blood flow and improve range of motion to the tissues involved could be an effective way to reduce injury risk and facilitate recovery.



A pre-training TMG report showing optimal function can give the coach confidence to prescribe maximal velocity sprinting and plyometrics for that day.



Using post-session TMG feedback, a coach can determine if adequate stimulus was prescribed and restoration is needed before additional intensive training (i.e. sprinting or plyometrics) occurs.

Want to learn more? Then check these out...

 For most results, the change in VC correlated with jump height and sprint speed.

 Decreased rectus femoris VC, jump height, and sprint speed after the strength and plyometric training sessions.

 Decreased biceps femoris Vc, jump height, and sprint speed after the sprint session.

 VC in both muscles and squat jump height increased after the technical workout.

 VC is a sensitive physiological marker to acute fatigue experienced in speed and power performance of rugby athletes.

Cody’s Comments “Participation in competition and training carries a massive emotional component to where an athlete is willing to sacrifice their own wellbeing in efforts to compete or train at a highlevel, regardless of fatigue and soreness. TMG offers the opportunity to remove the emotion from the situation and provide an objective and involuntary measurement of muscle function to better assess an athlete’s readiness. This can be a beneficial tool for athletes for improving their understanding of, gaining confidence in the effectiveness of, and performing safely with regards to training at a high-intensity. The primary limitation though is the money, time, and space needed to perform the assessment, but when you are considering the time-loss risk associated with a soft-tissue injury, TMG is a worthwhile investment, due to the ability of those that use it for monitoring and injury prediction. If the cost is too much to overcome, coaches can implement similar strategies in assessing neuromuscular function through jump, sprint, or throwing performance prior to training prescription. The drawback is the physical work required to assess readiness compared to TMG’s passivity.”

Technology & Monitoring

[Abstract]

Is the Push Band v2.0 a viable velocity-based measurement option? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Measuring velocity of resistance exercises is valuable feedback for training prescription, monitoring, and motivation (see infographic HERE). The Push Band v2.0 is an accelerometerbased system that is cost-effective and practical compared to linear position transducers (LPT), but previous research showed limitations with accuracy.

Twenty men attended six lab sessions during the testing period. Sessions one and four were for 1RM assessment and technique instruction of the squat, bench press, prone bench row, and seated overhead press, using free-weight or Smith machine variations in either session. The subsequent sessions consisted of simultaneous use of two Push Band v2.0 (attached to the bar and forearm), as well as a previously validated LPT GymAware device.

The primary findings in this study included:

This study assessed the validity and reliability of the updated Push Band v2.0 repetition velocity measurement across multiple loads and exercises using both free-weight and Smith machine variations.



measurements was similar between the LPT device and both Push Band v2.0 placements (bar and forearm).

 The velocities obtained from the LPT device exhibited near perfect correlations with those measured by both Push Band arrangements, with no significant difference in mean velocity values between devices.

Repetitions were performed at 30%, 60%,  The reliability and validity of velocity and 90% 1RM for each exercise and measurements were not affected by variation across the two subsequent the different loads or exercises sessions after familiarisation. Comparison performed across the study. and analysis was conducted for testretest reliability and concurrent validity of measurements for each device arrangement, exercise, and variation.

Practical Takeaways 

 The test-retest reliability of velocity

Numerous opportunities exist in using velocity feedback to determine the load or volume of work performed. 

Determining the amount of weight for a given exercise by matching bar velocity with the prescribed percentage 1RM (see infographic HERE) helps to optimise load.



Terminating a set at a specific velocity or percentage of velocity loss (e.g. 20%) compared to the best repetition of the set helps to emphasise quality repetitions.

Training sessions can be arguably more impactful with the Push Band v2.0, as there is an increase in athlete motivation, competition, and accountability for effort and performance with its use.

⇒ There may be better transfer to sport-specific actions (e.g. sprinting and jumping) by focusing on bar velocity and maximizing power output than focusing on maximum strength (see infographic HERE).

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Cody’s Comments “This is positive progress and support for using the Push Band v2.0, as earlier research has not found the same consistency in heavier free-weight exercises. The opportunity to use both bar and body mode interchangeably with good test-retest reliability, as well as concurrent validity with the criterion LPT, offers a lot of utility in the athletic performance training setting where it is sometimes difficult to capture and quantify the quality of work performed. The mean concentric velocity provided for the static exercises performed in this study allows for prescription and measurement of intent and quality. The next step in researching the Push Band v2.0 will be to assess the validity and reliability in peak velocity measurements from weightlifting exercises (i.e. snatch, clean and jerk) or ballistic exercises (e.g. jump squats, throws).”

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Fatigue & Recovery

Fatigue & Recovery This month’s top research on fatigue and recovery.

SOCCER-SPECIFIC TRAINING OR ACTIVE

RECOVERY: WHICH PROMOTES BETTER RECOVERY? Trecroci, A. et al. (2019) Journal of Strength and Conditioning Research. SHOULD AN ENDURANCE-SPORT ATHLETE COMPLETE HIGH-INTENSITY TRAINING BEFORE BED TIME? Thomas, C. et al. (2019) European Journal of Applied Physiology. HOW MUCH TIME DO SOCCER PLAYERS NEED TO RECOVER FROM A SPEED ENDURANCE TRAINING SESSION? Tzatzakis, T. et al. (2019) International Journal of Sports Physiology and Performance.

Fatigue & Recovery

[Abstract]

Soccer-specific training or active recovery: which promotes better recovery? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

In competitive soccer, players are frequently required to play in periods with congested fixtures in which they have limited time to recover between matches (3–4 days).

Nine sub-elite soccer players played two The main findings of this study were: 90 min friendly matches with similar match  Performing a low-intensity active activity profiles. On one occasion, 48 h recovery training session 48 h after a after the match, players performed a 60 soccer match promoted a better min soccer-specific training session restoration of muscle force of the consisting of small-sided games, tactical knee flexors after a match compared The authors in the current study compared drills, and set plays. On the other occasion, with a more traditional training session the function of the knee extensors and players performed a 30 min active composed of soccer-specific drills. flexors, as well as sprint performance, recovery session consisting of circle drills,  Conversely, both training sessions after completing soccer-specific training or dynamic stretching, and low-intensity induced similar recovery effects in an active recovery regime 48 h following jogging. repeated sprint performance and competition match. 72 h before, immediately after, and 72 h knee extension maximal voluntary after the match, participants were force production. evaluated for:

 Repeated sprint ability (5x30 m with 25 sec rest).

 Neuromuscular performance (maximal voluntary contraction of knee extensors and flexors).

Practical Takeaways 

⇒

If there is a succession of matches with limited recovery time in between, practitioners should prescribe lowmoderate training sessions 48 h after the match (i.e. circle drills, technical drill, positional work), to promote a better recovery of neuromuscular function of knee flexors. This could be particularly important with regards to injury prevention, since hamstring muscle strains are very common in soccer players, particularly in high match congested periods. In some competitive periods, when there is a high demand for technical and tactical aspects, these needs of the players preparing for the upcoming match cannot be disregarded. In these cases, practitioners should consider a soccer-specific training session (e.g. small sided games, tactical drills concerning attacking/ defending maneuvers), with limited distances covered in acceleration or deceleration, especially in cases where the player has compromised knee flexors force production, or the previous match induced high mechanical loads.

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Francisco’s Comments “This is a very interesting study that aimed to solve a real-world problem, can football athletes train in a match day (MD) +2/-1 without eliciting fatigue for the MD? Given the findings of the current study, particularly the observed decrease in the knee flexors force, the answer is “no”. At least with the characteristics of the training session that the authors have used. These results are not surprising and I don’t think teams often train in MD+2/-1. A more frequent scenario is when teams have 3 days between matches. It would be very interesting to understand the level of fatigue the players present on MD+2 and the effect of different training loads during that session when the team competes two days afterwards (i.e. MD+2/-2). Given these findings and from my experience, I would suggest coaches carefully plan and manage players to avoid the need of training on a MD+2/.1.”

Fatigue & Recovery

[Abstract]

Should an endurance sport athlete complete highintensity training before bed time? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

As has been well publicized in recent times, sleep is one of the most powerful recovery methods for athletes. Although the majority of this research focuses on team-sports athletes, a previous meta-analysis highlighted that endurance sport athletes, alterations to sleeping patterns and quality were most apparent following periods of high-intensity and high workload demands (see HERE).

Eight endurance-trained athletes (age=27.8±6.9 years) with a 10 km race time ≤41 min, took part in one of three protocols:

The main findings of the study were:

There is also evidence that suggests when an athlete trains can also impact on their sleep patterns and quality. It is recommended the best time for high-intensity exercise be performed in the evening (see HERE). However, much of this research is based on the general population, not athletes. Therefore, this study looked at whether any changes in sleep would occur amongst endurance athletes when training at different intensities in the early evening.

HIGH: 6×5 min @ 90% VO2peak with 5 min recovery.

LOW: 60 min at 45% VO2peak.

No exercise.

Each athletes sleep pattern and quality was measured with the use of polysomnography, wristwatch actigraphy, and subjective sleep quality (using the Consensus sleep diary). The cardiac autonomic activity of each athlete was also measured using a two-lead electrocardiogram as they slept.

Practical Takeaways  Those who deal with endurance sport athletes can have confidence that having them perform high-intensity training in the early evening, may not have a negative impact on their sleep pattern and quality.  Performing low-intensity activity in the early evening may also be another option for endurance sports athletes, as this does not seem to effect the nocturnal cardiac function of athletes. As stated by the authors of this study, this could be favourable should another training session be scheduled for the following morning.

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 Completing both HIGH and LOW running protocols increased sleep time in comparison to no exercise.

 The time athletes were awake was lower in both the HIGH and LOW protocols when compared to no exercise.

 None of the protocols significantly impacted on the actigraphy or subjective sleep quality of the athletes.

 When compared to the LOW and no exercise protocols, heart rate during sleep increased after completing the HIGH protocol.

Francisco’s Comments “The results of this study oppose the recommendations of the American Sleep Association, that suggest not performing high-intensity exercise in the evening due to the potential increase in arousal levels and impair sleep. Gaining sufficient, quality sleep is essential to all athletes due to the benefits it provides, particularly to the recovery process. Given that many endurance sports athletes are not typically as highly paid as their team-sports counterparts within the professional environment, many may still be required to hold a full– or part-time job. The results of this study show that should this be the case that, these athletes may be able to complete normal training activities once they arrive home without it impacting on their performance and recovery.”

Fatigue & Recovery

[Abstract]

How much time do soccer players need to recover from a speed endurance training session? OBJECTIVE

WHAT THEY DID

Speed-endurance training (SET) is extensively utilised to improve soccer players’ ability to perform repeated highintensity actions and delay fatigue. However, the amount of time required for full recovery following SEPT has not been investigated, which would optimise its use during a training microcycle.

Ten soccer players performed on separate The main findings of this study were: days two SET sessions, consisting of 8 allout 30 sec repetitions of a soccer drill with  SET induces short-term neuromuscular fatigue (up to 3 h) and either 150 sec (SET1) or 240 sec (SET2) rest a prolonged decrease of strength (up between repetitions. to 48 h), speed (up to 72 h), and jump performance (up to 24 h) after the To access acute fatigue, isometric strength training sessions; of knee extensors (KE) and flexors (KF) was

The authors looked to determine how much time is needed to recover performance, exercise-induced muscle damage (EIMD), and fatigue following two SET protocols in soccer.

measured before and 1, 2 and 3 hours after each SET. Before and 24-, 48- and 72 h after each SET, participants were evaluated for:

⇒ Isometric strength, concentric, and eccentric peak torque of KE and KF.

⇒ Countermovement jump and sprint performance.

⇒ Delayed onset of muscle soreness (DOMS) of KE and KF.

⇒ Creatine kinase activity (muscle

WHAT THEY FOUND

 DOMS and creatine kinase activity

remains elevated 72 h after performing a SET session.

 Time for recovery is reduced when longer work-to-rest ratios are applied (SET 2 vs. SET1).

 Performance deterioration following SET is less pronounced in athletes with greater velocity associated with maximal oxygen uptake, strength, and speed performance.

damage marker).

Practical Takeaways ⇒

The acute effects of SET last up to 72 h post training. Therefore, practitioners should consider this when planning the week’s training plan and avoid this kind of stimulus less than 3 days before a match.



In order to reduce the time to recover and still induce a high metabolic and muscular training load to players, practitioners should use longer resting intervals (e.g. 1:8 work-to-rest ratio) between high-intensity repetitions.



Additionally, up to 3 h following SET training, KF strength was still compromised which can enhance injury risk. Therefore, following SET, performing another highintensity drill later in the same session, or doing a highintensity gym session should be avoided.



This study also shows that players with better fitness status recover faster after SET, suggesting that practitioners should try to develop the endurance, strength, and speed of the players, particularly during the pre-season period. This is because it can influence not only their on-field performance, but also the player’s recovery within the week and presumably after matches.

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Francisco’s Comments “I found this study very interesting as there are not many studies investigating the effect that speed-endurance football exercise has on fatigue. This is particularly important as there are still a lot of misunderstandings on when and how to train within the training week. The findings from this article suggest that players require up to 72 h to recovery from ~300 m of high-speed running (distance covered at speeds >21 km.h-1). It is important to mention that the recovery kinetics are highly individual and highly dependent on the level of training (e.g. previous load exposition) of the athletes. From my previous experience (in Rugby), with a good progression over time, I can visualise soccer players doing such speed-endurance exercises 48 h prior to a game. This can be done by progressively increasing high-speed running distance from week to week, and therefore creating load resilience and robustness.”

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Youth Development

Youth Development This month’s top research on youth development.

BODY COMBAT™: THE ROLE OF MUSIC ON MOOD

IN ADOLESCENTS Kommers, M. J. et al. (2019) Journal of Physical Education. MULTIDIRECTIONAL PLYOMETRICS: HOW DO THESE IMPACT JUMP, CHANGE OF DIRECTION, AND DYNAMIC POSTURAL CONTROL? Jlid, M. C. et al. (2019) Frontiers in Physiology. KINETIC VARIABLES: THE EFFECTS OF MATURATION ON FORCE, MOVEMENT, AND JUMP PERFORMANCE Dobbs, I. J. et al. (2020) Journal of Strength and Conditioning Research.

Youth Development

[Abstract]

Body combat™: the role of music on mood in adolescents OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

According to the World Health Organisation, adolescents are encouraged to engage in 60 min of moderate to vigorous activity at least three times a week (see HERE). Physical activity at this age is essential for sustainable health and well-being. The creation of body combat™, a combination of martial arts and music, has proven popular with adolescents.

This study included twenty-nine adolescents (eighteen females and eleven males, aged 1215 yr) and to investigate the effects of exercise on mood with and without music, the author’s utilised a questionnaire known as the ‘List of Illustrated-Lowered States’. This questionnaire consisted of fourteen adjectives, with seven positive variables (i.e. full of energy), and seven negative variables (heavy/tired). To support the participants, a four intensities scale (4 = strong, 3 = strong, 2 = some, very little = 1) was used and was supported by illustrations of facial expressions.

This study found that there was an increase in positive feelings after participating in the body combat™ programme with music. The adjectives: "happy/joyful" (p = 0.0001), "spiritual" (p < 0.001), "active/energy" (p = 0.0263), "light" (p < 0.001) were frequently reported from participants.

The aim of this study was to analyse the effects of music on the moods of adolescents engaging in the body combat™ programme.

The body combat™ activity (see HERE) was performed on two Fridays with a one-week interval between operations to remove any interference from one test to the other.

Practical Takeaways 

A primary finding of this study was that feelings of “energy” and “happiness” often coincided with music accompanying exercise. Physiologically, music has long been associated with increasing work rate, reducing exercise monotony, and improving central nervous system adaptation. As a result of this, coaches could look to include age-appropriate music in their sessions. This should be in keeping with their preferences and maintain a consistent and fast pace.



The psychological benefits of music have been observed in this study. In another study (see HERE), the authors investigated the role of music in recovery periods. In response to stimulative music, peak power, heart rate, and blood lactate recovery levels were significantly lower in the group who had music present in their sessions. As coaches, chasing physiological adaptations are essential, so anything that can support performance, recovery, and development is important.



As a coach, many of the skills we develop transfer to music and dance. For example, rhythm, control, and tempo are all vital to allow movements to link and flow naturally. To do this, individual’s must be strong and experienced in their movement repertoire. In this lesson plan (see HERE), coaches can see how the skills of dance are taught and may not be as intimidating to teach as initially thought. As another resource, the attached podcast, hosted by dance choreographers Jana Kunitz and Julia Powers, discusses how coaches can incorporate three basic dance exercises into their fitness routines.

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The variables for negative feelings decreased: "Sad" (p = 0.0008), "unpleasant" (p = 0.0013), "shy" (p = 0.0001), and "scared" (p = 0.0001) when music was played. In comparison, positive adjectives were found to decrease in frequency in the absence of music. Finally, the “tired” adjective increased in class without music (p = 0.0020).

Tom’s Comments “Body combat™ is a fun and effective way of developing fitness, health, and well-being. Many S&C coaches will not feel comfortable teaching dance or exercise to music. However, I don’t think it needs to be that complex. Depending on the session type and athlete, music will often accompany my sessions to provide a background atmosphere. There are exceptions to this, particularly when we are addressing some complex lifts (e.g. Olympic lifting). However, from anecdotal experiences, I would say that these groups work far harder and at greater intensities. When working with youths, I have found music particularly useful when we are playing with different animal movements and levels (i.e. small, medium, and tall). For example, choosing a music theme (i.e. rainforest sounds) can be a fantastic way to get children to creatively identify and peercoach animal-based transitions. A “musical chair” style plyometric drill is also a great way to drive fun and performance. In summary, coaches should look to include music in their warm-up to drive motivation, happiness, and effort in sessions.”

Youth Development

[Abstract]

Multidirectional plyometrics: how do these impact jump, change of direction, and dynamic postural control? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Many soccer-specific movements involve highvelocity concentric and eccentric muscular contractions involving the stretch-shortening cycle (SSC). In this regard, plyometric training (PT) is known to improve SSC function and soccer performance.

The participants were twenty-eight male soccer players from a soccer academy aged 11.6 ± 0.8 yr). These participants were randomly assigned into an experimental group (EP) (n = 14) or a control group (n = 14).

The results of this study found that the MPT enhanced three important qualities that are relevant to the performance of young male soccer players. For the squat jump, a significant group x time interaction was observed (p < 0.05).

The main objective of this study was to investigate the effects of multidirectional plyometric training (MPT) on several performance variables related to soccer in young children.

The EP group were introduced to an 8-week MPT programme performed twice a week. The control group maintained their regular training routine. The programme consisted of three exercises per week in a vertical-anterior-posterior plane, vertical-lateral, and vertical-anterior-posteriorlateral plane.

For the countermovement jump and t-test, significant group x time interactions were also found in the EP (p > 0.05). However, the control group showed no significant improvements (p > 0.05). Finally, dynamic postural control performance improved in seven axes in the dominant and nondominant leg. Again, no significant results were found in the control group (p > 0.05).

To assess vertical jump height, a squat jump and countermovement jump were used. Agility-based performance was investigated using an agility Ttest. Finally, the star excursion balance test was used to assess dynamic postural control.

Practical Takeaways 



MPT proved to be an effective method of improving jump and change of direction performance. These qualities are essential to develop throughout a season, but should be progressed over time to avoid any overuse injuries. To support this, the attached resource from Michael Beale (see HERE) offers 126 effective warm-ups that are multidirectional in nature. When periodised, these can be highly effective at developing performance characteristics in soccer. To assess dynamic postural control, the star excursion test was used. This test is not only effective at assessing balance in both the dominant and non-dominant leg, but can be used as a method to track strength, range of motion, proprioceptive control, and limb-asymmetry. In the video below by PhysioTutors, some calculations that assess singlelimb function in the vertical-anterior-posterior plane, verticallateral, and vertical-anterior-posterior-lateral plane can be implemented in practice. Multidirectional plyometrics, in particular to the side (lateral) and backwards (posterior) are a relatively advanced plyometric exercise that place high stress on the muscletendon system (see HERE). In-place plyometrics require high levels of coordination and body control, so before advancing to multi-directional plyometrics, I would advise that players follow a protocol similar to the one offered by Rob Pacey (see HERE).

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Tom’s Comments “The present study was based on a progressive, moderate intensity exercise programme to minimise the risk of injury. This study is unique in its application of jumping in multiple directions, suggesting that this is not only safe, but an effective method of developing athletic performance. In the attached podcast, Lee Taft discusses the role of multidirectional development in athleticism, suggesting some of the ways he incorporates drills which allow “free play”, and then evolves them into more complex and extensive change of direction tasks. In the absence of growth-related hormones seen in children, the authors suggest that the improvements seen in this study are most likely associated with improved neuromuscular performance. Furthermore, as a result of improved muscle-tendon behaviour in the agonist and antagonist muscles during jumping, improvements in the concentric (squat jump: = +11.14%) and plyometric (countermovement jump = +9.91%) were seen. However, measuring strength alongside this, with the use of a handheld dynamometer, for example, would have supported this claim. In conclusion, such a program should be appealing to coaches as it requires very little time to complete, whilst showing some impressive results.”

Youth Development

[Abstract]

Kinetic variables: the effects of maturation on force, movement, and jump performance OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Strength and power are essential traits seen in cricket players, and engaging in resistance training can enhance strength and power in youth, irrespective of their age. However, the development of kinetic variables remains relatively unreported in the strength and conditioning environment.

Thirty-nine young male athletes (n = 24 prepeak height velocity [PHV], n = 14 post-PHV) aged 9-17 yr at a cricket academy took part in this study. Baseline testing for all groups was conducted one week prior to starting a 12week training programme and consisted of a back-squat assessment, an isometric midthigh pull (IMTP), squat jump (SJ), and countermovement jump (CMJ).

The results of this study found that there were no changes in the back-squat assessment (p > 0.05). When observing the IMTP data, it was revealed that only the post-PHV EXP group significantly increased absolute peak force and peak force rate of development. However, both EXP groups displayed significant increases in peak force at time epochs 0-90, 0150, 0-200, and 0-250 ms.

Maturity status was determined using a maturity offset and these groups were further divided into a control (CON) and experimental group (EXP). The training programme consisted of three mesocycles, with the first block aimed at developing skill, the second strength, and the third to develop strength through multijoint exercises.

With regards to the dynamic test, the pre-PHV EXP cohort improved concentric qualities in the SJ and CMJ (p < 0.005, d = 0.32). Moderate improvements were also found in the postPHV EXP group but not in the CON group. Finally, maturity-related differences were seen in short-term strength and power, but not movement competency.

The aim of this study was to examine the effects of a 12-week neuromuscular training programme on movement skill and force-time characteristics in male youth cricketers of different maturational status.

Practical Takeaways 



Kinetic variables that drive strength and power may be influenced by maturity status. When combined, plyometric and resistance training can be a great way to improve absolute peak force (see definition HERE). This was more prevalent in the postPHV EXP group, with the author’s suggesting that this was due to their advanced hormonal profile as a result of PHV. In older adolescents, I have found complex training to be a highly effective training modality (read more HERE). Complex training alternates exercises from a high load to a biomechanically similar plyometric exercise and can support the concurrent development of both force and velocity characteristics. An often underdiscussed issue associated with improving an individual’s force potential is an increased demand for technical focus, with an increased mass/force potential sometimes leading to injury. In this study, those in the post-PHV group showed higher peak landing force following their CMJ. During this time, coaches must ensure that their athletes understand the correct ways to land. In THIS article, the author provides some practical examples of “good” jumping practice. Although this study showed some promising results, it is important to remember that this was over a relatively small period (12-weeks). To develop a greater understanding of the interactions between time and training, coaches should keep a record over time to build an understanding of how an athlete(s) develop in their chronological band.

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Tom’s Comments “Despite some of the limitations of this research (sample size, adherence, CON vs. EXP contact time), this research makes a fantastic contribution to our understanding of youth S&C. Specifically, a well-blended programme consisting of upper- and lower-body strength and plyometric training is safe and beneficial for youth. In the attached podcast, Dr. Jordan Feigenbaum discusses the unique role that S&C can have in a youth’s development. The IMTP is a fantastic test to identify an individual’s force-producing capacity but can be expensive. If as a coach you are interested in using this measure, I would advise that you contact local facilities/universities that may have one to use. In the attached article (see HERE), the team at Simplifaster provide a “how-to” guide, as well as discussing all of the options and variables that can be measured through the IMTP protocol. When combined with the CMJ, the dynamic strength index (see HERE) can be calculated, which could have easily been calculated in this study as advice for the participants.”

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Nutrition

Nutrition This month’s top research on nutrition.

CANNABIDIOL USE IN PROFESSIONAL

SPORT: IS IT REALLY WORTH THE RISK? Lachenmeier, D. W. & Diel, P. (2019) Sports. DOES DIETARY NITRATE INTAKE EFFECT HUMAN SKELETAL MUSCLE NITRATE STORES? Wylie, L. J. et al. (2019) The Journal of Physiology. DOES CHEWING CAFFEINE GUM AT HALFTIME BENEFIT RUGBY UNION PLAYERS? Russell, M. et al. (2019) The Journal of Strength & Conditioning Research.

Nutrition

[Abstract]

Cannabidiol use in professional sport: is it really worth the risk? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

In 2019, Cannabidiol (CBD) was probably one of the most talked about products within the health, sport, and medicine settings (listen to a related discussion with the podcast below). Widely claimed effects of decreased anxiety, fear, memory extension, and anti-inflammatory properties have resulted in many professional athletes taking this cannabinoid and even some beginning their own companies.

The authors introduce this commentary by highlighting the fact that cannabis is illegal in many jurisdictions and has also been included on the World Anti-Doping Agency (WADA) list as a substance prohibited in-competition.

CBD is structurally related to the main psychoactive compound tetrahydrocannabinol (THC), which is responsible for the adverse effects of cannabis. Although nonpsychoactive, it may be responsible for some advantageous effects, including anti-inflammatory properties, relief of arthritis, and pain-related behaviours, as well as postexercise recovery. Most of the CBD products worldwide are available as food supplements or compounded foods, with CBD or hemp extract as an ingredient. Such unapproved products normally do not comply with quality standards.

This brief commentary presents a clear and robust warning to both professional and amateur athletes against the use of such products.

Although there are claims of cannabis being helpful for extreme sports (e.g. rock climbing, freestyle skiing, skydiving), as it may improve muscle relaxation and reduce anxiety, there are only a few studies regarding its effectiveness, with previous reviews concluding there is a lack of evidence regarding performance-enhancing effects. Clearly smoking cannabis is not advisable, but more recently the interest lies with CBD, which is one of the cannabinoid compounds naturally found in Cannabis sativa.

The WADA has excluded CBD from its list of prohibited cannabinoids, however, it is important to note that according to the 2020 WADA prohibited list, cannabinoids in general are still listed in group S8 – substances forbidden to be used in competition. Importantly, most CBD products are sold as so-called full-spectrum products, meaning they also contain other cannabinoids. As such, the use of full-spectrum CBD products is definitely prohibited by WADA. Studies have detected residual levels of THC in CBD products with 10 out of 28 commercial CBD products from the internet and retail market, and more than a third of all the available products would probably lead to a falsepositive urine doping test.

Practical Takeaways 

The CBD market is a highly unregulated and uncontrolled market currently, making it a minefield for any athlete. The easy answer is to simply not purchase.



Should your athletes choose to consume this substance, it is wise to know that the threshold for a positive THC test has been set by WADA to 150 µg.mL-1 of 11-nor-9-carboxy-THC in urine.



Many studies of CBD products have detected considerable mislabelling of content, resulting in athletes not really knowing what they are purchasing. If an athlete wishes to purchase a CBD product, they must ask the producer to provide credible analytical proof for the claims about CBD content on the labels.



Health Span Elite have recently released Levagen + Sport, a tested product that has similar effects to CBD.

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James’ Comments “CBD received a lot of attention last year and this looks set to continue into 2020, with products now containing CBD as a drink (see video below). Although CBD itself is not banned, it’s the actual content of the commercial products that often contain banned substances, such as THC and other unregulated cannabinoids. For me, this risk alone should deter athletes and also be enough of a point for practitioners to raise with athletes who are considering trying it. If athletes are seeking assistance with things like sleep, recovery, anxiety, soreness, and inflammation, I believe there are many other proven strategies that would help or improve each area for the athlete. For example, if your athlete is sitting on their phone in bed, this maybe the reason they are struggling with sleep. Advise would be to work on their current sleep hygiene practices. Likewise, if they are struggling with soreness, are they eating enough of the correct nutrients to help muscles recover and repair? Advise would be to increase protein intake and antioxidants.”

Nutrition

[Abstract]

Does dietary nitrate intake effect human skeletal muscle nitrate stores? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

It is well established that nitric oxide can regulate blood flow and muscular contractions, so much so, that it is now common practice for athletes to increase their intake of dietary nitrates leading into competition to improve performance outputs (the infographic below summarises this). A simple example of this is the popular nutrition supplement 'Beet It', a beetroot -based fluid shot and food bar that contains high levels of dietary nitrates.

Thirteen participants completed preexperimental visits on two separate occasions. On the day before visits, participants consumed a low-nitrate diet. After baseline blood and muscle biopsy samples were established, participants ingested either a 140 mL of concentrated nitrate beetroot juice or 140 mL of concentrated-depleted beetroot juice.

Nitrate (226 ± nmol.g-1) and nitrite (5.7 ± 7.4 nmol.g-1) concentrations in skeletal muscle were much higher than in plasma (nitrate: 54 ± 27 nmol.g-1; nitrate 0.2 ± 0.2 nmol.g-1).

In rodents, the concentrations of nitrate in skeletal muscle has been found to be far greater than in blood, but this finding is not universal in humans. With this in mind, this study investigated if concentrations of nitrate could be stored in human muscle and be further increased through dietary nitrate ingestion.

Another set of blood and muscle samples were collected before the commencement of a highintensity “step” exercise test until the point of task failure. Following task failure, blood and muscle samples were again collected to signify post-exercise.

Practical Takeaways 

These findings suggest that skeletal muscle may act as a nitrate and nitrite ‘reservoir’ and supports the practical strategy for athletes to increase dietary nitrate consumption.



Practitioners should encourage athletes to increase daily and weekly nitrate consumption, with a focus on those days and evening meals leading into performance, this is discussed in the podcast and video below. For example, increasing dietary nitrate consumption on the day before match-day and the pre-match meal should be a focus for athletes.



Increased dietary nitrates can be consumed from eating foods like beetroot and leafy greens mixed in a salad. A rhubarb crumble the day before competition, would provide an increased intake of nitrates and can act as a strategic dessert option for practitioners.

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Following the ingestion of dietary nitrate, the concentration within the blood and muscle increased 3-fold, whilst the consumption of a placebo supplement did not alter plasma or muscle nitrate and nitrite concentrations. Nitrate concentration was substantially higher in skeletal muscle than in blood and is elevated further by dietary nitrate ingestion. Finally, highintensity exercise resulted in a decrease in the nitrate stores in skeletal muscle following supplementation.

James’ Comments “The research into nitrate and nitrite is now fairly extensive, with most studies agreeing that consuming higher levels of nitrates leading into exercise results in an improved performance. Reading this article, it’s now an exciting time for the research into this area and how dietary nitrate enhances muscle fatigue resistance through skeletal muscle interactions. In the applied world, many athletes consume popular nitrate supplements, but do remember that substantial amounts can be found in food sources as well. In the future, I think we will begin to see more studies looking at the impact of nitrates on recovery from performance. With this in mind, linked HERE is a make at home bar made from beetroot for those who want to give it a try and save the pennies instead of purchasing the Beet It bars.”

Nutrition

[Abstract]

Does chewing caffeine gum at half-time benefit rugby union players? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Rugby is a physically demanding collision sport which lasts for 80 min. Players typically use the half-time interval to rehydrate, refuel, and rest ready for the gruelling second-half to begin. Literature has demonstrated reduced exercise intensities in the time immediately following half-time relative to the beginning phases of a match.

Fourteen Welsh regional academy players participated in a randomised, placebo-controlled, crossover study. Following pre-exercise measurements, players chewed placebo gum (PLA) for 5-min before completing a standardised warm-up and repeated sprint testing. After this, during a 15-min simulated half -time period, players chewed either caffeine (CAF 400mg; 4.1 mg.kg-1) or PL gum for 5-min before completing a second repeated sprint test.

Half-time caffeine ingestion had no effects on sprint performance, blood lactate concentrations, salivary cortisol concentrations, or cognitive function testing.

The aim of this study was to investigate if consuming caffeine gum during a simulated half-time period altered the performance, physiological demands, and cognitive effects in academy rugby players.

Trials were separated by 7-14 days and were completed at least 48-h after any competitive match.

Practical Takeaways 

Chewing caffeinated gum provides a practical and logistically feasible method of administrating caffeine, especially when traditional methods of pills and drinks may not be as appropriate.

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Having said this, it is worth sampling different methods with your players during pre-season matches or training matches to identify what each individual player prefers. For example, a shot of espresso, caffeine gum, caffeine gel, or caffeinated sports drink. An example of different caffeine content within a cup of coffee is included in an infographic I have done previously and included below.

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Although physical and cognitive performance indices were not influenced by caffeine gum, practitioners seeking enhanced testosterone concentrations should consider recommending caffeinated gum to their players.

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Results indicated that salivary testosterone concentrations were elevated above placebo values at the onset of a second repeated sprint bout following consumption of caffeine in gum-form. In particular, values at the second sprint test were 70% (97 ± 58 pg.ml-1) greater in CAF vs. PLA.

James’ Comments “The majority of players I have worked with in the past consume some form of caffeine at the start of the game and during halftime, as previously discussed in a Rugby World article (see HERE). In this reviewed study, the data demonstrates the influence caffeine gum has on testosterone levels during simulated half-time periods. Readers should remember that there is a clear difference between simulated half-times and actual half-times of competitive fixtures. For example, the cognitive activity and hormonal release that players experienced during this study, I believe, would be completely different to those experience from the England players at the Rugby World Cup final half-time. Learning from experience, it is very important to practice different caffeine strategies with players before the first competitive fixture. For example, having your goal-kicker consuming too much caffeine at half-time, resulting in them being over aroused lining up for a kick in the final moments of a match is not an ideal situation. Different players prefer different options and not all like caffeine gum. Therefore, it is important to remember that caffeine can also effect players (sometimes negatively) recovery and sleep, as highlighted in the video below.”

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Injury Prevention & Rehab

Injury Prevention & Rehab This month’s top research on injury prevention and rehabilitation.

WHAT IS THE IMPACT OF EXTRACORPOREAL WAVE THERAPHY WHEN COMBINED WITH A SINGLE-LEG SQUAT PROTOCOL? Lee, W. C. et al. (2020) Clinical Journal of Sport Medicine. WHAT IMPACT DOES FOOT POSTURE HAVE ON LOWER-LIMB INJURIES IN PROFESSIONAL BASKETBALL PLAYERS? Lopezosa-Reca, E. et al. (2020) Journal of Sport Medicine. CAN THE APPLICATION OF KINESIO TAPE HAVE AN IMPACT ON TRUNK ISOKENTIC STRENGTH? Buke, M. & Unver, F. (2019) The American Journal of Sports Medicine.

Injury Prevention & Rehab

[Abstract]

What is the impact of extracorporeal wave therapy when combined with a single-leg squat protocol? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Patellar tendinopathy is a common diagnosis in the athletic population who partake in jump-related sports, such as basketball and track and field. Using an eccentric exercise program has been a popular treatment in recent times in reducing overall pain and dysfunction amongst these athletes. It has been thought that the stimulus provided when using eccentric exercise promotes tendon and collagen remodeling (see HERE).

Thirty-four male in-season athletes with patellar tendinopathy (>3 months) from local volleyball, basketball, and handball teams were randomised into two groups. Subjects were excluded if they had signs of patellofemoral pain syndrome, fat pad irritation, meniscal injury, osteoarthritis, rheumatoid arthritis, infection, history of lower-limb fracture, inflammatory myopathy, previous patella tendon cortisone injection, or other interventions for patellar tendinopathy within three months

The key findings in this study were:

This study compared the effects of a 12-week singleleg eccentric decline squat exercise with and without extracorporeal wave therapy (ESWT) (see HERE) on patellar tendon stiffness, tendon strain, and function.

The exercise group completed 12 weeks of single-leg decline squat exercise program, whereas the combined group performed the same program, in addition to a weekly ESWT session in the first 6 weeks. The eccentric strengthening program consisted of 3 sets x 15 reps performed twice a day. Mechanical properties, including tendon stiffness and strain, were examined using ultrasonography and dynamometry. A visual analog scale and the Victoria Institute of Sports Assessment–patella (VISA-p) score was used to assess pain and dysfunction.

Practical Takeaways  Eccentric strengthening should be utilised by physical therapists working with athletes with tendon specific injuries, as this exercise mode has been shown to facilitate tendon remodelling, decrease pain, and improve function  When explaining the proposed methods of eccentric strengthening in tendon function, these include decreasing tendon stiffness and increasing tendon strain, which is important to facilitate the tendon’s ability to mechanically buffer the force transmitted through the tendon during jumping and landing  Physical therapists can utilise the VISA-p in the assessment of patella-related injuries, as greater improvement on these scores is correlated to greater clinical outcomes.

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After a 12-week eccentric exercise following either a single or combined program with ESWT, tendon stiffness reduced by ~15%.

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Greater reduction in tendon stiffness was associated with greater improvement in VISA-p score.

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Increase in the tendon strain was associated with a reduction in the intensity of self-perceived pain and a trend in improvement in VISA-p score.

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Combining eccentric exercise and ESWT did not appear to be more effective than exercise alone in patients with patellar tendinopathy.

Jordan’s Comments “Patellar tendinopathy can be debilitating in athletes involved in jumping sports, if not addressed properly. Eccentric exercise strengthening, as well as heavyslow resistance training, are two methods that have been shown to decrease pain and improve tendon function. Although treatment will be focused to the area involved, it is important to evaluate and address the entire kinetic chain, as often times there are deficits seen in the hips and ankles that further impact function of the knee. One of the limitations of this study was that it only included the male population, so future studies should look to investigate these exercise modes and their effect on the female population with a larger sample size.”

Injury Prevention & Rehab

[Abstract]

What impact does foot posture have on lowerlimb injuries in professional basketball players? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Within the sport of basketball, athletes are required to accelerate, decelerate, change direction, move laterally, as well as jump and land on a continual basis. Performing these fast-paced and explosive movements at a fast pace can predispose an athlete to injury. The most common injuries sustained in basketball include lateral ankle sprains (47.8%), patellar tendinopathy (17%) and ligament injuries (15 %) (see HERE).

Two hundred and twenty basketball players were recruited from two major league basketball teams (Asociacion Club de Baloncesto and Liga Espanola de Baloncesto) in Spain from October 2011— October 2014, with all players ≥18 yr with at least 10 yr of basketball experience. Players were excluded from participating in the study if there was any presence of a serious foot injury that could have produced morphological change in the past six months, poor balance, or edema in the foot or ankle.

The key findings in this study included:

The aim of this study was to investigate the association between foot posture, lower-limb injuries, and position in professional basketball players.

The foot posture index (FPI) is a six-item instrument with a scoring system from –12 (highly supinated) to +12 (highly pronated) that was used to evaluate the nature of the athletes’ foot posture in all cardinal planes. Sports injury data was collected from the teams and was classified into the most common injuries.

Practical Takeaways 

Ankle sprains and patellar tendinopathy are the two most common injuries in basketballers, regardless of position. Pysical therapists and strength coaches should then prioritse the strengthening of functional movement patterns including the squat, hinge, and lunge proprioception exercises like single-limb stance on uneven surfaces with dynamic movement, as well as jumping and landing mechanics, which will lead to improvements in force absorption and force production.

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Physical therapists and strength coaches should analyse foot posture, as well as position played in basketball when performing an assessment, as there has been a positive correlation made with injury occurrence .

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Knowing which foot type is more likely to be found in a specific position, physical therapists, as well as strength coaches can prioritse positionspecific interventions to target those areas.

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Ankle sprains and patellar tendinopathy were the most common injuries for all foot types regardless of player position.

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The centre position was the most affected by lower-limb injuries, followed by the forwardcentre, the shooting guard, and the point guards.

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Point guards had an average FPI of –0.48 (supinated to normal), whereas centers had an average FPI of 5.15 (normal to pronated foot).

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Shooting guards and forwards were +1.78 and +3.08, respectively (normal in both cases), and the forward-centres presented the highest scores at +4.26 (pronated foot).

Jordan’s Comments “This study shows us that ankle sprains and patellar tendinopathy were the most common injuries found in basketball. Since patellar tendinopathy was found more in supinated feet, future studies should look at specific interventions to address these foot postures and see their effect on patellar tendinopathy. One limitation of this study was that the athlete’s previous injury history wasn’t taken into consideration which could have skewed the data obtained in regards to the most common injuries. Further studies should also look into recovery factors like hydration, sleep, and nutrition which was not included in this study as these have been shown to have an overall effect on injury occurrence in the athletic population.”

Injury Prevention & Rehab

[Abstract]

Can the application of Kinesio tape have an impact on trunk isokinetic strength? OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Kinesio tape is a therapeutic tape that can be applied to the body for musculoskeletal system disorders, as well as central and peripheral nervous system disorders. Kinesio tape has many proposed effects on the body, including stimulating muscles, decreasing tension, stimulating circulation, and addressing pain and edema.

Forty university female students were divided into two groups; a placebo group (PG) and an experimental group (EG). All kinesio tape was applied bilaterally alongside the erector spinae from the posterior superior iliac spine towards the transverse process of ipsilateral T12 vertebrae.

The key findings in this study were:

This study examined the effects of kinesio tape on trunk strength when immediately applied at different angular speeds on healthy women, as well as 48-h after its application.

For the PG group, kinesio tape was applied with the students standing straight and the tape was applied without tension. In the EG group, the students were asked to touch their toes and the tape was applied with 50% stretch. Trunk strength measurements via an isokinetic dynamometer were analysed three times at two different concentric angular speeds of 60°.sec-1 (low angular velocity and 180°.sec-1 (high angular velocity) at the beginning of the process, immediately after kinesio tape application, and 48-h post-application.

Practical Takeaways ⇒ Kinesio tape is a type of therapeutic taping technique targeting receptors in the nervous system. Taping can be applied after manual therapy to alter pain perception and provide stability to muscles and joints prior to the implementation of exercise. ⇒ Kinesio tape that is applied with a level of stress can enable an increase in trunk strength when measured using an isokinetic dynamometer at high speeds.  Taping should not replace traditional strength training for increasing strength in certain muscle groups and should be used to complement a well-rounded rehabilitation or performance program.

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In both the PG and EG groups, isokinetic measurements taken before the taping process were similar.

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In both the PG and EG groups, there was no significant difference measured in peak torque immediately after taping at the two angular speeds.

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In the measurements taken 48-h later in both groups, there was a significant increase in trunk extensor force at 60°.sec-1 angular speed, while there was no significant increase in trunk flexor-extensor force at 180°.sec-1 angular speed

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The EG group had significantly higher force results in both evaluations (immediately after kinesio tape application, as well as 48-h afterwards).

Jordan’s Comments “Although there was a positive effect found with an increase in trunk strength with the application of kinesio tape when measured at high speeds, the increased strength could have been a placebo effect, as the groups did not know which taping technique they received. Taping should be used as a reinforcement in a treatment paradigm after a manual therapy technique aimed to decrease pain and improve range of motion. After this, however, the focus should be on strengthening to reload a system in order to produce maximal adaptation. Future studies should look at how long an increase in strength lasts after a taping application, as well as utilise a more diverse patient population.”

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Learn. Coach. Reflect. Repeat. A simple tool for self-development

Growth only happens outside of your comfort zone. Neale Donald Walsch

Reflect on your learning, ask yourself these 3 important questions…

#1 What did I learn from this issue that I didn’t know before?

#2 How is this new knowledge going to influence my coaching from now onward?

#3 What questions do I have around implementing this new knowledge?

CHALLENGE: Don’t Re-Invent the Wheel Now you’ve challenged yourself cognitively, challenge yourself emotionally by posting what you’ve learned (question #1), how this will influence your coaching (questions #2), and ask the group to help answer your questions surrounding this new knowledge (question #3). Ask the other coaches in the group If you don’t challenge yourself cognitively and emotionally, you want to grow and achieve your coaching goals, you’ll just stay as you are. #growthmindset

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