Was it the amount of rounds that did Ali in for his long term health?

Plenty of folk get Parkinsons and have never taken part in combat sports, however fact is getting punched in the head damages brain cells, most do not get badly affected by it, whereas others do.

Add in the fact that most people who start to show neuro deficits, then do not afterwards risk head trauma by getting hit in the face by 200+ pound fit strong athletes, as Ali did.

When he faced Holmes he was taking double prescribed dose of thyroxine, and allegedly not taking in enough fluids, that sure as hell is not wise when you are going to have Holmes bouncing punches off your head.

So as others have said the amount of punches/rounds certainly did not help the situation, did they cause the Parkinsons, that we cannot definitively say.

 

So many factors - the number of rounds certainly played a role, but he also became lazy in training ... leading, of course, to taking more punishment in fights. Plus, the inevitable decline from age (though again, consistent and serious training could have forestalled that factor as well). His habit of letting his sparring partners tee off on him in the mistaken belief that it somehow toughened him up added to the wear and tear. Even without the Parkinson's (boxing related or not), he had a lot of hard, unnecessary miles on his body