ABSTRACT
When compared to our mammalian cousins, humans are fairly unremarkable in terms of physical performance. The very fastest humans are capable of top sprinting speeds of just over 10 metres per second, while other mammals can achieve speeds nearly three times as fast. However, our capabilities in endurance running (defined as the ability to sustain running for extended periods of time using primarily aerobic metabolism), although not comparable to other mammalian endurance specialists, are unique among the primates. This has led to the belief that our endurance abilities have been central to our evolutionary history (Bramble and Lieberman 2004). Our unique endurance ability relative to the other primates is due to a number of adaptations beneficial to endurance running in the genus Homo. Some of these adaptations, such as narrowing of the hips, are traceable in the fossil record to all members of the Homo genus. Others, however, such as lengthening of the legs relative to body mass are more recent adaptations, first identifiable in the more recent Homo erectus. Further skeletal adaptations such as shortening of the femoral neck to reduce stress during running are specific to Homo sapiens (modern humans). These adaptations and their importance in endurance running are reviewed in detail by Bramble and Lieberman (2004). Modern humans exhibit wide variation in every aspect of their physicality. Although the timescales are short (~150,000 years) relative to the age of the Homo genus (~2 million years), it is intriguing to consider that some of this human variation could contribute to the variation in endurance running potential between individuals and populations.
