Human physical performance capability is influenced by environmental factors, such as physical training and nutrition,as well as inherited, genetic factors. Scientific advances identifying the genetics of human physical performance have accelerated in recent years, and over 150 genes have been associated with performance phenotypes or health-related fitness to date (Rankinen et al., 2006). However, whilst human endurance performance phenotypes are highly polygenic (Spurway 2006), the way in which the typical distributions of the polymorphisms influence physical performance potential has not been examined. Therefore, the purpose of this study was to evaluate the likely genetic influences on physical performance potential (a) in individuals and (b) in populations. Initially, we searched the scientific literature for associations of human genetic polymorphisms with endurance performance, or an endurance phenotype, via either association studies or case-control studies between elite athletes and the general population. Twenty-two genetic polymorphisms were identified. Next, the typical distributions of those genetic polymorphisms in the general population were obtained from suitable literature. Using probability theory applied to those 22 DNA variants currently associated with human endurance performance, we found significant homogeneity in terms of genetic predisposition to high performance potential, such that 67% of people have a profile that differs by no more than two genotypes from the typical profile. Moreover, 99% of people have a profile no greater than six genotypes more `favourable` than the typical profile. Applying our data to population statistics, our results demonstrate that the 22 DNA variants currently associated with human endurance performance give only a 0.002% chance of a single individual in the world having the `preferable` form of each of those 22 variants. When applied to a medium-sized nation (the UK), there is only a 1 in 5 million chance that an individual exists with the `preferable` form of each of the 22 variants. With population turnover, the chance of such genetically gifted individuals existing increases. Thus, we conclude that the highly polygenic nature of human physical performance traits means that (i) the similarity of polygenic profiles limits the extent of human physical performance and (ii) with population turnover, world records should continue to improve even without further enhancement of environmental factors.
© Copyright 2007 12th Annual Congress of the European College of Sport Science, Jyväskylä, Finland - July 11-14th 2007. Alle Rechte vorbehalten.