I have an ElliptiGO. It's a standup bicycle. You don't pedal; you stride on it. It allows me to have the same striding motion as running without the impact.

Pain is the body's way of ridding itself of weakness.

If someone had said to me before I started doing this that a human being is capable of running 100 miles nonstop, I would have just said: 'No way. I mean, how?' If you just go out there and run 100 miles, it breaks down a lot of barriers in terms of self-imposed limitations.

Don't run with your legs, run with your heart.

I love surfing, rock climbing, cycling - all that stuff. But it's just amazing that I can inspire people with my running. It's humbling, really.

When I ran across America, for 75 days I ate 10,000 calories a day. I still lost about five pounds.

Sure I'm cut but not for the sake of vanity.