All this talk of not stretching or warming up properly sounds nice and smart. However, I'm the one with the pulled hamstring at the moment.
I went for an hour run before class, cooled down for a bit (on the way to class), muscles tightened up, then RIP! - actually, it was more like a POP!
I should have known better than to accept that stupid stretching routine!
I'm the fool here for not following my gut and my experience!!