A few more from Chris McDougal's Born to Run:
"Make friends with pain, and you'll never be alone." - Ken Chlouber, founder of the Leadville 100
"You don't have to be fast, but you better be fearless." - Aron Ralston, famous for amputating his own arm with a pocket knife to free himself while being pinned under a boulder
"He who loves his body more than dominion over the empire can be given custody of the empire." - Lao Tzu, Tao Te Ching
"Often, I visualize a quicker, like almost a ghost runner, ahead of me with a quicker stride." - Gabe Jennings, 1500m runner
"Poerty, music, forests, oceans, solitude - they were what developed enormous spiritual strength. I came to realize that spirit as much or more than physical conditioning, had to be stored up before a race." - Herb Elliott, Olympic miler
My favorite of the bunch:
"I don't want anyone to do anything except come run, party, dance, eat, and hang with us. Running isn't about making people buy stuff. Running should be free, man." - "Caballo Blanco," a.k.a. Micah True, a.k.a. Mike Hickman