Fitting into Our Genes: Evolutionary Theory of the Health Benefits of Physical Activity

Abstract

ABSTRACTThere is ample evidence that regular physical activity can prevent or delay a large number of chronic health conditions in humans, and the evolutionary theory of the health benefits of physical activity may provide insight into this phenomenon. Because the physical activity of tracking/hunting game and constantly searching for other food, water, and resources was necessary for the survival of our Paleolithic (hunter-gatherer) ancestors, evolutionary selective pressure ensured the propagation of genes that optimally supported acute and repeated bouts of physical activity. In contrast, genes that did not optimally respond to physical activity were lost to natural selection over millions of years. The Neolithic (agrarian) descendants of the hunter-gatherers also led lives of high physical exertion, to which their inherited genes (programmed to expect physical activity) responded in a healthy fashion. Unfortunately, modern sedentary behavior promotes the unhealthy expression of physical activity-responsive genes, thus precipitating chronic disease and premature mortality. As the modern-day chronic disease epidemic expands seemingly unchecked, it is increasingly important to reintroduce widespread physical activity to a species genetically pre-programmed to thrive on it, thus fitting into our genes.