A thread on the Strngth and Conditioning forum about the old "spirit training" stuff (holding horse stance, holding buckets of water at arms length, etc), reminded me of when I realized that my coaches/teachers were not BS'ing when they talked about mental toughness and how much of performance is in your head as much as in your muscles.
I was in training in the Army, we were doing this 6 mile run every morning, and we were getting really good. This was an elite school, we were in killer shape, and, even with equipment (weapons, ruck, etc) we were getting cocky. We were bellowing cadence at the top of our lungs on the way back into camp, holding our weapons overhead as we ran, that sort of stuff.
One morning, as we came in from this run, the Sgt leading us ran right past our usual stopping point, in front of our barracks. No big deal at first, probably just going to have us fall out at one of the training areas. But no, he headed out the gate, with our formation on hus heels, and made the turn that put us right back at the start of out 6 mile loop. 30 seconds back, we were not tired, but within a couple of hundred yards guys started to drop. We lost about 25% in the first mile, but no one after that. Everybody who made that first, spirit crushing, "Oh no, can we make another 6 miles" stage, finished it all.
I am posting this over here, even though it is a little off topic, because Scott's stuff seems, to me, to closely relate to the reality of this type of thing.
Read my article in my "Musings" at my forum (RMAX.tv) on "Toughness Training" - it distinguishes between mental and physical toughness.