The problem is everyone wants the quick fix. The human body doesn't really work like that. It likes to compensate for the environment it is in, and when you introduce those kinds of things, your body will move to adapt to it.
Modern pharmacologicals can a wonderful thing, but the human immune system is supremely complex. Tinker around with it, and your body will sometimes attempt to go the other way which can be a problem with immune tinkering drugs for eczema, arthritis or psoriasis GLP-1s? Seem like a great thing, but I'm waiting cautiously to see if there is any back end. Phen phen was the new hotness until it turned out it was burning out heart valves. GLP-1s seem to help a lot of people, so I'd hate to see in 3 years it makes your pancreas melt.
Same with self-administered drugs. Modern hyper-weed roasting noggins over the long term, home brew concoctions popping mental circuit breakers, and the new fav, fentanyl, which just plain shuts your lights off.
All I know about running is that Jim Fixx, the patron saint of running, dropped dead at 50 in perfect health. That's all I need to know.