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

In this smart volume, Harvard paleoanthropologist Lieberman (The Story of the Human Head) takes a scientifically astute look at exercise. Alongside actionable workout tips, he proffers persuasive reasons for everyone to exercise in some way (his preferred activity is running), notably that “physical activity is probably the single best way to lower the risk of Alzheimer’s disease,” and that an active lifestyle can help “to prevent or tame... several kinds of cancers.” To help win over “habitual non-exercisers,” Lieberman has some refreshingly realistic suggestions for “mak[ing] the exercise less disagreeable,” such as rewarding oneself for completing workouts, or doing them in like-minded groups for moral support. Meanwhile, the recommendations for exercisers in general are helpfully straightforward and unfussy (“exercise several hours a week, mostly cardio but also some weights, and keep it up as you age”). To explore why humans can but don’t always build strength, Lieberman traces “two conflicting threads” in Homo sapiens’s evolution—as early humans became hunters, they “must have benefited from plenty of brawn,” but human society’s becoming “less reactively aggressive and more cooperative... reduced selection for being big and strong.” His illuminating and frequently humorous work will delight fitness mavens and make those pesky workout sessions more rewarding for everyone else. (Jan.)