And a list of quotes I found on-line:

 Surfing for Running Wisdom
 When you are 99 miles into a 100-mile running race, your brain is not
 the same brain you started with.

 Paul Huddle

 Any idiot can run a marathon; it takes a special kind of idiot to run
 an ultramarathon.
 Alan Cabelly

 The race continued as I hammered up the trail, passing rocks and trees
 as if they were standing still.
 Red Fisher, Wasatch '86

 It hurts up to a point and then it doesn't get any worse.
 Ann Trason

 If you start to feel good during an ultra, don't worry you will get
 over it.
 Gene Thibeault

 You have to forget your last marathon before you try another. Your mind
 can't know what's coming.
 Frank Shorter

 Life is short. Running makes it seem longer.
 Baron Hansen

 Most people run a race to see who is fastest. I run a race to see who
 has the most guts.
 Steve Prefontaine

 Some of the world's greatest feats were accomplished by people not
 smart enough to know they were impossible.
 Doug Larson

 We can't all be heroes because someone has to sit on the curb and clap
 as they go by.
 Will Rogers

 Marathoning is like cutting yourself unexpectedly. You dip into the
 pain so gradually that the damage is done before you are aware of it.
 Unfortunately, when awareness comes, it is excruciating.
 John Farrington, Australian marathoner

 Jogging is very beneficial. It's good for your legs and your feet. It's
 also very good for the ground. It makes it feel needed.
 Charles Schulz

 To a runner, a side stitch is like a car alarm. It signifies something
 is wrong, but you ignore it until it goes away.
 Anonymous

 It's unnatural for people to run around the city streets unless they
 are thieves or victims. It makes people nervous to see someone running. I
 know that when I see someone running on my street, my instincts tell me
 to let the dog go after him.
 Mike Royko