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. 34 THE AUSTRALIAN ORIENTEER DECEMBER 2008
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.
If you’re 5kg overweight it’s like running in an O-suit that weighs 5kg. 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
