For me, challenging myself with this type of endeavor [ultramarathons] brings the best out in me because even at the darkest, deepest moments when I feel like I can't go on, when I feel like there's no chance I could break the record or much less finish the trail, somehow I find that strength inside of me.

Humans aren't built to sit all day. Nor are we built for the kinds of repetitive, small movements that so much of today's specialized work demands. Our bodies crave big, varied movements that originate at the core of our body.

Train where your fitness is NOW, not where you want to be.

As powerful as our legs are, as magnificent as our lungs and arms and muscles are, nothing matters more than the mind.

Every single one of us possesses the strength to attempt something he isn't sure he can accomplish. It can be running a mile, or a 10K race, or 100 miles. It can be changing a career, losing 5 pounds, or telling someone you love her (or him).

We all lose sometimes. We fail to get what we want. Friends and loved ones leave. We make a decision we regret. We try our hardest and come up short. It's not the losing that defines us. It's how we lose. It's what we do afterward.

You can hurt more than you ever thought possible, then continue until you discover that hurting isn't that big a deal.