Over the next 14 years, Karnazes challenged almost every known endurance running limit. He covered 350 miles without sleeping. (It took more than three days.) He ran the first and only marathon to the South Pole (finishing second), and a few months ago, at age 44, he completed 50 marathons in 50 consecutive days, one in each of the 50 states. (The last one was in New York City. After that, he decided to run home to San Francisco.) Karnazes' transformation from a tequila-sodden party animal into an international symbol of human achievement is as educational as it is inspirational.
Worth reading the whole thing- including how he eats pizza while running!