Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

by Daniel E. Lieberman

Although there is much variation, PALs of hunter-gatherers average 1.9 for men and 1.8 for women, slightly below PAL scores for subsistence farmers, which average 2.1 for men and 1.9 for women.21 To put these values into context, hunter-gatherer PALs are about the same as those of factory workers and farmers in the developed world (1.8), and about 15 percent higher than PALs of people with desk jobs in developed countries (1.6). In other words, typical hunter-gatherers are about as physically active as Americans or Europeans who include about an hour of exercise in their daily routine. In case you are wondering, most mammals in the wild have PALs of 3.3 or more, nearly twice as high as hunter-gatherers.22 Thus, comparatively speaking, humans who must hunt and gather all the food they eat and make everything they own by hand are substantially less active than average free-ranging mammals.