If you are a textbook boxer, then it never hurts to be big and light so you can turn that overhead shot down on a shorter opponent who won't be able to hit you. I would not like to be built like Hearns, but for boxing from a textbook outside style, Hearns, Hopkins, Sugar Ray Robinson, Dawson, Lennox Lewis, Sugar Ray Leonard, and the Klits have a pretty good "tall for the weight/ strong enough to hurt you" kind of shape.
You could just as easily say you shouldnt run because its bad for your knees. Deadlifting is a great way to strengthen pretty much your whole body. Haye supposedly can deadlift 300kgs Pretty much any serious athlete incorporates them into their workout. Also its easy to pick out the few guys in great shape who got KO'd by heavy guys. You can also point to the guys who are in tremendous looking shape who are at the top of the game. Bradley, Kirkland, Froch, Haye,Wlad Klitschko are all in ridiculous shape. Even look at older fighters like Holyfield, Tyson, prime RJJ. They were all incredibly cut. If you were just to look at Tyson with his shirt off,you'd assume he was just a bodybuilder or weight lifter. Having muscle doesnt necessarily make you un-athletic and muscle bound. Pretty much every serious boxer these days has a strength and conditioning coach who has them on a lifting regime.
but guys who spent more time on skill were able to compete as old past it men. Larry Holmes looked like a blob, but at 42 or so he was still going the distance with prime Holyfield and beating undefeated Ray Mercer, who almost did a number on Lennox Lewis. Skills pay the bills - those 1980s guys at the upper echelon didn't gas like this current crop of shorter, stockier, and "strength conditioned" athletes. Guys like Pryor never ran out of gas.
There is no "ideal" physique it's different for every fighter. Plus physique is just the look of a fighter. You can't tell a fighters strengths or weakness based on looks alone. In general fighters should have strong hips, neck and back. Hips and back is where the power comes from and having a strong neck helps you to be able to sustain punches.
People bring that up all the time. This guy didnt have a great physique but was awesome etc. Well imagine if he WAS in great shape! People act like conditioning and skills are mutually exclusive. Does Wlad suffer from lack of skills and gas just because hes big and ripped. Prime Lewis look in amazing shape, yet I dont think he lacked anything because of it
at one smoker I fought a guy built like Thomas Hearns and that **** sucked. (no weigh in, I was 5'8'' 130 at the time and he was 6'2'', 147 or so. Crappy crappy crappy. Would not relish fighting Hearns. My best bet was to turn it into a weight lifting contest)
Wlad Klitschko has a PHD in Sports science. And he says running is hard on the knees so he prefers swimming for his cardio. He believes swimming is a better exercise.
It is UTTERLY UNPROVEN "chubby" heavyweights perform worse than fit heavyweights. for example it was "fat" Ali that could take the punches that made people like his chin and not the cruiser weight Ali that got hurt really bad by Henry Cooper. Not saying Ali was fat but he wasn't Ken Norton like. It's all about conditioning, frank Bruno looked like mr universe and Louis Monaco was a mr universe. One guy was a bum and the other was a guy without stamina.