The Agony of Victory - When Winning Isn't Enough. Book of fairly short biographies on professional athletes.
Graeme Obree features, the guy who broke cycling world records using a homemade bike made from scrap metal and washing machine bearings.
He would ooze blood from the mouth because he pushed through pain thresholds that doctors couldn't fathom.
Another story was one of a female long distance runner, one day during a training run she falls down a cliff face, or something like that.
The authorities can't find her, but she is eventually found by her dog after nearly dying. I don't think she ever made a return to the sport due to the injuries that resulted.
Another story (this one hit home for me being a pro-basketball player with a diagnosis of schizophrenia), was of a college basketball prodigy.
The guy never got picked up to play professionally beyond his college career, after putting up leading numbers, and soon after that his mind spiraled.
It's an interesting story of isolation and his former teammates felt guilty that they never picked up the phone after their college careers to check in on him.
He was diagnosed with schizophrenia, believing there was a government conspiracy against him.
I'm sure, although I don't remember, that he'd of felt the same about being picked up as a pro.
Teammates remember him as normal, but when they came to think about it, after training sessions and matches he would go home solo, whereas the team would socialise.
There's quite a few other stories in the book, but it's been years since I read it and I'm sure VT doesn't need me to re-write the book in this post.
Oops, too late!