Abstract

The malleability of mammalian biology during early life, which carries considerable weight throughout the course of the lifespan, may contribute to the creation of a human phenotype ideal for prime physical performance. In this article, the authors consider the East African cohort of exceptional athletes that dominate marathon performance. Since entering international marathon competition in 1960, East Africans have competed at the front of the pack and now hold the top 10 men's marathon times. The authors present lines of evidence supporting that exposure to factors such as altitude and early metabolic adjustments that are inherent in East African early life exert a strong influence in later life physical performance and may collide with a genetic advantage to induce biological changes that allow for a more robust biological response to training in later life.