Starts off with the amusing andedocte about  Karnazes  eating a pizza while running. Then covers his childhood in which he competed in track and field in highschool, buut stopped running at age 15 until age 30. 

The book doesn't really explain why  Karnazes  runs. Or give much tips or insights into his training, though there's a new section at the end that is interesting. Spends too much time on some of his adventures, like running a marathon to the south pole. Whole things sounded stupid and boring.