This turned out to be an awesome book, and I didn't think it would be in the first 50 pages. I thought this was heading to some mystical hippie BS, given the beginning makes it sound like this "Stone Age" tribe had superpowers and the author was in search of this mysterious "gringo indio" in Mexico's Copper Canyons known as the "Caballo Blanco." I should have known better given it was the Christmas gift of my favorite science geek. (Thanks Jenn!) The subtitle calls it the story of a "hidden tribe, superathletes, and the greatest race the world has never seen" and it lived up to its title. McDougall started with a simple question: "Why do my feet hurt?" And in answering that question the book looks to physicians, physiologists, evolutionary biologists, Bushmen in a "persistence hunt"--and the strange breed known as the "ultramarathoner" who compete in races as much as 100 miles or 100 kilometers in length. And it takes us to that "hidden tribe," the Tarahumara of Mexico, who call themselves "the running people" and have been able to beat elite professional athletes. Some other questions along the way? Why is it that "no woman [has] ranked among the top fifty in the world in the mile... A woman might sneak into the top twenty in a marathon," yet women are competitive--even routinely win--ultramarathons. Why do aspects of our anatomy resemble horses and dogs more than chimps or pigs? And why might we be better off running barefoot than with Nike sneakers costing hundreds of dollars? The book is written like a novel, withholding and giving information skillfully in ways that come together beautifully. It was a surprisingly moving, even inspiring book. After reading some books in the past months about atrocities and the horrible things humans do to each other, this finally gave me back pride in being human.