WHAT DOESN'T KILL US

On the heels of the paleo diet comes a new claim: taking on the physical challenges of the environment faced by our prehistoric ancestors can undo what easy calories and effortless comfort have done to our bodies—made them fat, lazy, and weak.

In his latest book, investigative journalist and anthropologist Carney (A Death on Diamond Mountain: A True Story of Obsession, Madness, and the Path to Enlightenment, 2015, etc.) expands on his 2014 Playboy piece, “The Iceman Cometh,” in which he profiled Dutch fitness guru Wim Hof and experienced Hof’s strenuous training methods, some of which involve exposing the near-naked body to snow and icy water. At first skeptical, Carney became convinced by the changes he experienced in his own body. The narrative is filled with personal details that will engage, astonish, and even repel readers. Expanding on his unnerving close-up account, the author also examines the research being done on the role of brown adipose tissue in the body and a variety of military and sports medicine training practices. He cites the anecdotal evidence of people who have placed their faith in Hof and are convinced that his techniques have changed, if not saved, their lives—e.g., sufferers of Parkinson’s disease, Crohn’s disease, and rheumatoid arthritis. As a climax to his account, Carney describes how, stripped to the waist, he accompanied Hof on a climb to the summit of Mount Kilimanjaro, Africa’s highest peak. In the epilogue, the author asserts that his experiences showed him that “exposure to cold helps reconfigure the cardiovascular system, combat autoimmune malfunctions, and is a pretty darned good method to simply lose weight.” Hof provides the book’s foreword.

Couch potatoes take warning: the experiences described in this testimonial are often tough to read about, and the conclusions, while sometimes convincing, might best be taken with a touch of skepticism.