So odd. I am a fitness trainer and an avid runner. I have never felt runners high and it has rarely if ever cleared my head or broken a funk I may be in. Maybe I’m a mutant of some kind! :-o
I ran Xcountry in HS in the sixties, not that I was any good at it, but I did it. To me it was pure torture, to be honest. After every race I would castigate myself for being such a wussie, and resolve to do better. It was good for my health, though. I had the heartbeat of a tree stump.