I took me a while thinking about it and reading the whole thread before coming to my conclusion. I have to give him a thumbs up. His willingness to push is, to me, admirable but not unprecedented. The following passage is from John Brant's 'Duel In The Sun' although the story has been written about in other places including '14 Minutes.'
"The most famous example of his ability to deny pain, of course, had come at the Falmouth race in 1978, when he'd been so overheated and dehydrated that he was administered the last rites of the Catholic Church, and his father, standing above him with the makeshift cross, had delivered the seeming miracle.
"From that race, his legend was born. Alberto Salazar would run to the point of death. 'A lot of people asked me, "Well, are you going to be scared to push yourself again?" I wasn't,' he told a reporter later. 'That fall, I broke through tremendously. It was completely from that Falmouth race. I won the NCAA cross-country championship and continued to improve. So Falmouth was a turning point in my career. It just made me mentally tougher.' "
How many mentally soft runners have made it big? Some, perhaps. Rupp has dropped out prior to needing hospitalization and even because of less-than-ideal weather. Even he, however, is undoubtably mentally stronger than many of us amateurs. Any successful pro likely is. Nevertheless, the willingness to go literally as far and fast as your body can is an asset some of your competitors may not have in their arsenal. (The period in Salazar's life recounted above predates synthetic EPO and various other controversial substances widely used today.)
Another side to that coin exists, of course. Push enough and it is possible to impair your ability to do so again. At that point, your competitors will have an actual physical advantage over you that no mentality can overcome. Still, if running success is your only goal, you may decide that it is worth anything to win a race as long as you don't pay the ultimate price, which Al nearly did.
The book cited is, of course, about the 1982 Boston Marathon. In unseasonable heat, Salazar again pushed his body very far but not quite to the edge. In fact, he may have done permanent damage in the 'Duel.' Again, from Brant:
" 'After Boston, I was never quite the same. I had a few good races, but everything became difficult. Workouts that I used to fly through became an ordeal. And eventually, of course, I got so sick that I wondered if I'd ever get well.'
"Salazar's warm smile briefly turns wintry. For a moment, his poise falters, and he seems like a traumatized man, who after long therapy, can finally talk about his past.
" 'It took me a long time to connect the dots,' he says, 'and see that the line stretched all the way back to Boston.' "