Don't confuse comfort with happiness.

I run because if I didn’t, I’d be sluggish and glum and spend too much time on the couch. I run to breathe the fresh air. I run to explore. I run to escape the ordinary. I run…to savor the trip along the way. Life becomes a little more vibrant, a little more intense. I like that.

There is magic in misery. Just ask any runner.

The human body has limitations. The human spirit is boundless.

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.

Running is a simple, primitive act, and therein lays its power. For it is one of the few commonalities left between us as a human race.

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.