Any goal worth achieving involves an element of risk.

I never feel more alive than when I'm in great pain, struggling against insurmountable odds and untold adversity. Hardship? Suffering? Bring it!

Don't confuse comfort with happiness.

I run with a credit card and a cell phone, so when there is not a 7-Eleven around, like some of the country roads out there, I can get him to deliver a pizza to me. And I kind of give them a coordinate, a corner.

Regardless of how distant your dreams may seem, every second counts.

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.

I've raced on all seven continents at least twice. I've probably run thousands of races. But the single race that I'm most proud is a 10K. Yes, a 10K. I ran it with my daughter on her 10th birthday.