In this myth-busting book, Daniel Lieberman, professor of human evolutionary biology at Harvard University and a pioneering researcher on the evolution of human physical activity, tells the story of how we never evolved to exercise. As our increasingly sedentary lifestyles have contributed to skyrocketing rates of obesity and diseases such as diabetes, Lieberman audaciously argues that to become more active we need to do more than medicalize and commodify exercise. Drawing on insights from evolutionary biology and anthropology, Lieberman suggests how we can make exercise more enjoyable rather than shame and blame people for avoiding it, and tackles the question of whether you can exercise too much, even as he explains why it can reduce our vulnerability to the diseases mostly likely to make us sick and kill us.