Great book (if you’re a runner) about the Tarahumara Indians of Mexico’s Copper Canyon, who it claims are the greatest distance runners in the world. It really kickstarted the barefoot running fashion when it came out.
He argues that humans are natural runners. We do ourselves a disservice by wearing shoes, and make ourselves more likely to be injured. Lots of stuff about forefoot running and about the pointlessness of stretching before running. Various comments on diet. Good points about the need to challenge the body so that it adapts as part of training.