the one that hung above my desk for all of engineering school was:

"whether you think that you can or you can't, you are probably right" - henry ford

certainly applies to triathlon as well for me.

Lance Armstrong:
"Pain is temporary; quitting lasts forever."

“Nothing tastes as
good as being lean feels”.  – Jack Lalane

"Git R Done"

and

"Hard work pays off in the future, laziness pays off now"

Larry the Cable Guy!

"Should" and "Will" are two totally different things.

"You don't have enough talent to win on talent alone." Herb Brooks

"You can always quit, and they won't care, but you will always know."-- John Collins

"Excitement is for the beginning. Victory is for the end. Faith is for the middle."

"you climb pretty good for a fat guy"

Eddie would go.

(If you're not a surfer, you may have to look it up.)

"Go NOW"

There is an 80% chance I could be wrong, but I believe they trained the olympic athletes to tell themselves this on their last 50/100 meters.  I tried it and it works!

Life is not a journey to the grave with intentions of arriving safely in a pretty well-preserved body, but rather to skid in broadside, thoroughly used up, totally worn out and loudly proclaiming ... WOW! What a ride!

or

I actually have this as my last line on my RoadID wristband and in Latin in my Sig. line

"Man up, Crack On"

I used to have a t-shirt that said EDDIE with GO behind it.

We also have "Pain is weakness leaving the body"

"Make the hurt feel good"