There are a million reasons why you can't. Focus on the few reasons why you can.

I try to think about positive things - how great my form is, how my arms are swinging, my breathing, how loud people are cheering. My sports psychologist taught me there are a million things telling you you can't keep going, but if you find the things that say you can, you're golden.

I don't feel like myself unless I run. It's how I deal with sadness and happiness. I need it. It's like therapy.

Hill sprints are good for everyone!

Don't try to rush progress. Remember -- a step forward, no matter how small, is a step in the right direction. Keep believing.

The journey isn't always perfect, but always worth taking.

I have a power word that I use-when I qualified for the Olympics in 2008, it was fighter. That way when I'm in the race and I get to those dark moments, I can think of the word and it evokes that emotion for me.