Push Yourself to Go Farther, Longer. "How long is an ultramarathon? Technically an ultramarathon is any foot race longer than a marathon." So begins Chapter 1 of James Shapiro's Ultramarathon. Practically it is about twice as long as a marathon, covering 50 miles, 62 miles, 100 miles, or more. Five hours on a track, or 6 or 8 or 24. Practically, it is a punishing undertaking, but exhilarating to experience. Author...