6 - Working capacity and constitution

Summary

Some physiologists have held that the unusual performance of the top athlete is based largely on inherited traits – as P. O. Åstrand (1967) put it: ‘I am convinced that anyone interested in winning Olympic gold medals must select his parents very carefully.’ Garn et al. (1960) have marshalled evidence for a packaged transfer of the genes that contribute to success in competitive sports; in particular, they note a mesomorph is much more likely to be the offspring of large-framed parents than of either large– and small-framed parents or two small-framed parents. This chapter will bring together data on the inheritance of working capacity, including formal genetic studies and more empirical comparisons of performance where constitutionally different subjects have lived in the same environment or subjects of similar initial constitution have lived for many generations in contrasting environments.

Genetic studies

Variance of data

Working capacity data from isolated communities might be expected to show a small coefficient of variation. Inbreeding in itself is unlikely to be sufficient to reduce the variance of a complex trait such as working capacity, and P. T. Baker (1974) has argued that if selection for an adverse environment is still proceeding, only a proportion of the population will show favourable adaptive traits, and the variance of data for the community may be increased. However, the life-style of an isolated population tends to be more homogenous than that of a large industrial city with respect to such factors as physical activity and environmental stress.