Human evolution, and hence natural selection through Darwinian fitness, is sometimes considered the central concept of biological anthropology. As the study of anthropology has turned increasingly to contemporary human population biology, and especially to more practical issues related to the attainment and maintenance of health, interest in the study of variation in different physiological functions has greatly increased. Therefore, studies of populations in a variety of ecological settings and of individuals exposed to unique stresses such as those associated with rigorous training for sport are now a mainstay of contemporary biological anthropology. Such studies, needless to say, also contribute significantly to the development of general theory about human biology and human variability.

The so-called ‘healthy life-style’, which includes physical activity as an essential component, is an objective of many, especially in developed countries. This is quite apparent in the relatively rapid growth of the ‘physical fitness industry’, including sales of exercise equipment (especially for the home), weight control centres, comprehensive adult and/or corporate fitness programmes, and so on. Further, current research on risk factors for several degenerative diseases, such as cardiovascular disease, obesity and non-insulin-dependent diabetes, indicates a potentially beneficial role for regular physical activity. Several diseases, especially of the cardiovascular system, may be prevented, or their development delayed, by the incorporation of sound programmes of regular physical activity, among other aspects of life-style such as diet.