Bodybuilding an "extreme"? No.
Marathon running an " extreme"? No.
Unless you're talking about abusing massive amounts of drugs and dangerous methods to become some 300 lb monster... Or repeatedly entering 100 mile mega-marathons.
Lots of area in between. Seems you have a very narrow view of what bodybuilding is.
Every person who trains with weights, from the day they start to whenever they get close to their goals, is "bodybuilding", if you want to use the true definition of the word.
http://time.com/4803697/bodybuilding-strength-training/
(Some good info in there)
Also, running doesn't damage everybody that does it. Some get hurt... Many don't.
For what I do/did, I had to utilize a combination of both heavy weight training and lots of cardio. LOTS of both, actually.
I've been examined many times by doctors & no adverse effects from either.
I was talking about people who are obsessive runners and obsessive bodybuilders, but i am going to bow out from this thread gracefully.