Seminar with Professor Daniel Lieberman

Almost everyone knows that physical activity is healthy, but there is  less awareness of the extent to which lifelong physical activity  —particularly during middle and older age— promotes health. We also lack  an ultimate, evolutionary explanation for why humans are less likely to  remain healthy as they age in the absence of regular physical activity  including its modern manifestation, exercise:  discretionary physical  activity undertaken for the sake of health and fitness. Here I show that  humans were selected to be more physically active than other apes  throughout our unusually long lifespans, including the several decades  after we cease reproducing. I then propose and review how metabolic and  physiological stresses induced by physical activity promoted selection  to allocate energy away from harmful overinvestments in fat storage and  reproductive tissues and towards repair and maintenance processes that  slow senescence and reduce vulnerability to many forms of chronic  diseases. As a result, extended human health spans, hence lifespans, are  both a cause and consequence of habitual physical activity, helping  explain why lack of lifelong physical activity can increase disease risk  and reduce longevity. I will conclude by considering how an  evolutionary anthropological perspective on physical activity can help  encourage more people to exercise without being exercised about it.