In the Army, we run. ALOT.
I've never been a fast distance runner (two mile times in the upper 15:00's on average). Before my knee surgery (and at 205 lbs, btw), I was working my *** off to be able to keep my 2 mile time under 17:00 (the maximum passing time for minimum score on out physical fitness test) due to just plain not running. After I had my knee surgery and was out of the game for three months, I decided that I was going to work my way past the 15's and into the 13:00's after my recovery.
I've found that before, my body just wouldn't cooperate with my mind. Lately, I've found that my mind plays a much bigger role in my running than it used to.
Recently, I'm running in the 13:45-14:10 range for 2 miles. Much more gooder, I must say. Perhaps even much more betterer...depends how far you wish to slaughter the language.