Dean Karnazes, a New York Times bestselling author and an internationally recognized endurance athlete, was named by Time magazine as one of the Top 100 Most Influential People in the World. He has competed on all seven continents, including a 350-mile run, a 135-mile ultramarathon across Death Valley, and a marathon to the South Pole in negative 40 degrees. In 2006, he ran 50 marathons, in all 50 US states, in 50 consecutive days, finishing with the NYC Marathon, which he completed in three hours flat. He has written for Runner’s World and Men’s Health and lives in Marin County, CA.