10 minute read
TRAINING
Physique, Body Composition
and Performance
Steve Bird
Physique and body composition
To perform well in any sport requires a combination of factors from the realms of physiological fitness, technical skills and mental aptitude. Other factors that have an influence on performance are physique and body composition. Physique relates to height, weight and muscle mass, whilst body composition specifically refers to the body’s proportions of fat and lean tissue, including muscle. The study of physique is known as somatotyping and rates a person’s body in three categories. These are: (i) Endomorphy - roundness and fatness; (ii) Mesomorphy – muscularity; and (iii) Ectomorphy – tallness and thinness.
Physique and sport
The demands of different sports often require particular body types. For example, basketball players tend to be tall, endurance runners lean, and weightlifters muscular. And whilst it is possible to participate in a variety of sports at a recreational level without having the ideal physique, it is often essential at an elite level. For example, people of all shapes, sizes and body compositions complete Marathons, but at an elite level they will all be lean (moderate to high ectomorphy), with a low % body fat (low endomorphy), and moderate musculature. In other sports the principles also apply, so elite male gymnasts must be muscular and have a high mesomorphy score, whilst also having a low body fat and therefore a low endomorphy score. By comparison male sumo wrestlers need to be muscular and have a high mesomorphy, but they also tend to have high levels of body fat and therefore have a high endomorphy score, but a very low ectomorphy rating because they are heavy for their height. Compare these with male and female high jumpers who tend to be tall and thin (high ectomorphy score), and have a low endomorphy (low body fat), whilst having a moderate muscularity (mesomorphy). Consequently, from a line-up of a basketball player, jockey, weight-lifter, and endurance runner you could probably pick their sports just by looking at them.
Orienteering physique
As covered in previous articles, the overall fitness requirements for orienteers are similar to those of other endurance runners. These are a high capacity to utilise oxygen, and sustain this use for a prolonged duration. It is therefore not surprising that the physiques of elite orienteers are similar to those of other endurance runners. However, as previously indicated, Orienteering also has some unique elements due to the challenges of the terrain and environment, and consequently an orienteer’s fitness has to reflect this, as does their physique. At club level orienteering, the participants come in all shapes and sizes, and even at the elite level they vary in height, as well as differing in their muscularity. But what is common at the elite level is the relatively low body fat of the best performers, and this has long been demonstrated in research by Creagh and Reilly1 . The characteristic of a relatively low % body fat amongst successful endurance runners2 is essentially because surplus body fat has to be carried as additional weight, without contributing to our energy needs, or generating the muscular power that’s required when we run. From a practical perspective, this means that if we had two runners with the same VO2 max (measured in litres of oxygen used per minute), and the same muscle mass, the one with more fat has to carry that extra weight, and is likely to be a slightly slower runner. And at an elite level an extra 2 - 5kg is likely to be significant.
The importance of a person’s capacity to use oxygen relative to their body weight is why sport scientists express the VO2 max of runners relative to their body weight. Thus it is expressed in units of millilitres of oxygen per kilogram of body weight per minute (ml/kg/min), and in the example above the fatter orienteer would have a lower VO2 max (~5% lower) if it was expressed relative to their body weight. By contrast, in sports such as rowing, where body weight is supported, it is expressed directly as litres of oxygen per minute (L/min), which is a better indicator of fitness in these non-weight bearing sports. So for an orienteer, in gross and somewhat simplistic terms, if you’re 5kg overweight it’s like running in an O-suit that weighs 5kg, which is obviously not ideal. However, note that the additional weight associated with carrying a drinks pack during an event is a somewhat different perspective, as although it does add weight and may slow you down minimally, this is more than offset by the benefits of maintaining effective hydration and energy levels; as the failure to do so will slow you down by even more than the additional weight.
Essential and Storage Fat
Certain aspects of physique and body composition are inherent, and have limited or no potential for manipulation and change. For example, training will not affect your height, and whilst muscularity can be altered through appropriate training, the extent of the changes are also constrained by inherent factors. However in contrast, percentage body fat is highly dependent upon lifestyle, as evidenced by the associated increases in food intake (calories), particularly junk food, reduced activity levels, and the increased preponderance of obesity in the general population. So percentage body fat can be altered through changes in dietary intake and energy output. This is a sensitive area, as attaining the right level of body fat is a balance between not having too much (which therefore constitutes excess weight), and not having enough, which has adverse health consequences as well as being detrimental to
performance. Within the body, fat can be classified as ‘Essential Fat’ and ‘Storage Fat’. ‘Essential Fat’ is required for normal physiological functioning, and if it becomes depleted the body mal-functions, becomes ill and death can result. In healthy men ‘Essential Fat’ should constitute around 3% of their total body mass (weight) and is found within the heart, lungs, liver, spleen, kidneys, intestines, muscles, bone-marrow and nervous system. Women require higher levels of ‘Essential Fat’ (~12%) with the additional amounts being associated with gender-specific fat deposits. These include breasts (~4%)3 and deposits around the pelvic, buttock and thigh regions4. So, as previously indicated, women are predisposed to carrying this additional ‘Essential Fat’, which cannot be reduced without adversely affecting health and performance, and as discussed in previous articles, this is a major factor in explaining the current performance differences between men and women in running events (~10%). Therefore, whilst ‘Essential Fat’ should not be reduced below normal levels and is essential regardless of sport and activity, the remaining fat - ‘Storage Fat’ is something that we should be aware of when assessing the suitability and idealness of our physique and body composition for competitive success in Orienteering. ‘Storage Fat’ is contained in adipose tissue, and is found in the fatty tissues that surround organs in the thoracic and abdominal cavities, where it provides physical protection. It is also stored in subcutaneous (beneath the skin) adipose tissue.
It is these fatty stores that we are perhaps most conscious of because they are visibly evident, affecting our body shape and aesthetics. In the average male and female these represent around 12% and 15% of our total body mass, which when combined with the aforementioned ‘Essential Fat’ gives totals of around 15% and 27% respectively. Although with current trends in obesity the values for ‘Storage Fat’ may now be somewhat higher. Attaining the optimum physique and body composition For endurance runners, such as orienteers, it is the ‘Storage Fat’ that can be reduced below these ‘average’ values to produce the leaner physiques associated with successful performance. And although reports vary, it would appear that ‘Storage Fat’ can be reduced down to 5% or even less in elite males and females, giving total values (when combined with the ‘Essential Fat’ ) of around 8% and 17% for males and females respectively. However, it should be noted that different methods of assessing body composition may produce slightly varying values, so these should not be used as a target. For most people, the issue is preventing the accumulation of excess ‘Storage Fat’ and/or getting rid of the excess that they already have. In basic terms the best regimen for this is a healthy diet and regular training. Obviously the more you train, the more calories you burn and the more fat you utilize. And if the calorific intake of your food is less than that used by the combination of exercise, general daily living activities and your basal metabolic rate, you will deplete your ‘Storage Fat’. This has to be a careful and gradual process, as 1kg of ‘Storage Fat’ contains around 7,500 calories (kcal) which is the equivalent to over 80 km of running. And if you reduce your dietary intake by too much, you’ll deplete your muscle glycogen stores as well as your fat, and the lack of glycogen will make training very difficult, as well as tending to make you irritable and grumpy. Indeed, if you are intending to lose weight it is prudent to seek the advice of a professional sports dietician5 who will assess your needs and develop effective strategies that suit your requirements.
‘Essential Fat’ cannot be reduced without adversely affecting health and performance. Don’t become too lean
Based on various studies, it is suggested that for females, if their body fat levels decline by too much, and some suggest that values below 15% are problematic, then they are at increased risk of hormonal disturbances, with an associated risk of irregular menstrual cycles (oligomenorrhea), and the complete cessation of menses (amenorrhea). The hormonal disturbances may also cause long term health problems with an increase in the risk of low bone mineral density (osteopaenia and osteoporosis) and the potential for osteoporotic fractures in later life. So it’s very important to get it right.
Summary
• Successful orienteers tend to be lean; • The best way to attain a healthy and competitive body composition is through training and a healthy diet; • Don’t lose too much body fat, or you’ll affect your ‘Essential Fat’, which will be bad for your health and orienteering; • A healthy body composition is also a competitive body composition.
References
1. Creagh U, Reilly T. (1995). A multivariate analysis of kinanthropometric profiles of elite female orienteers. J Sports Med Phys Fitness. 1995
Mar;35(1):59-66. 2. Bale P et al. Anthropometric and training variables related to 10km running performance. Brit.J.Sports Med. - Vol. 20, No. 4, December 1986, pp. 170-173 3. Katch VL and Behnke AR. Contribution of breast volume and weight to body fat distribution in females. Am J Phys Anthropol. 1980
Jul;53(1):93-100 4. McArdle WD, Katch FI and Katch VL. (2007) Exercise Physiology:
Energy, Nutrition & Human Performance (6th edition). Pub: Lippincott
Williams and Wilkins 5. http://www.sportsdietitians.com.au
Professor Steve Bird is at RMIT University, Melbourne. Steve worked with the Great Britain National Orienteering Squad for over 10 years and is now assisting the Victorian Junior Squad.
ORIENTEERING PUBLICATIONS
IOF Publications
International Specifications for-Orienteering Maps .......... $11.00 Competition rules for IOF events ................. $11.00 Control Descriptions ............ $11.00 Simple Maps for Orienteering .... $11.00 Trail Orienteering (BOF book) ..... $30.00 Trail Orienteering (booklet) ........ $8.25 Trail O (leaflet) ................. $0.70
Australian Publications
Elementary Orienteering Instructors-Manual ............. $13.20 Level 1 Coaching Manual ........ $22.00 Level 1 Coaching Syllabus ........ $3.90 Level 2 Coaching Syllabus ........ $4.40 Level 3 Coaching Syllabus ........ $4.40 Among the Best Orienteers (video) $19.75 Sponsorship & Advertising, 1996 . . . . . . . . . . . . . . . . . available from states Club Guide, available on disc.
Prices include GST and postage within Australia for single copies. Prices for bulk orders available on request. Orders should be addressed to Orienteering Australia, PO Box 284 Mitchell BC 2911, with cheques made payable to Orienteering Australia. Email: orienteering@netspeed.com.au
