As long as my heart's still in it, I'll keep going. If the passion's there, why stop?... There'll likely be a point of diminishing returns, a point where my strength will begin to wane. Until then, I'll just keep plodding onward, putting one foot in front of the other to the best of my ability. Smiling the entire time.

The human body is capable of amazing physical deeds. If we could just free ourselves from our perceived limitations and tap into our internal fire, the possibilities are endless.

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.

There is magic in misery. Just ask any runner.

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.

I went to college, grad school. I got an M.B.A., had a really cush corporate job. But I was just bored stiff. I didn't fit that mold.

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.