i watched 24-7 last night and canelo looks like a linebacker. his arms are several inches bigger then his calves. Guy looks like he is gonna tip over. This baffles me. If anything he needs to lose all that bulk and be quicker. His punches arent gonna have half the speed or snap. Total mistake by canelos camp.
Canelo' biggest concern is being able to take GGG's punch. Of course putting some extra muscle on is beneficial for that, more muscle on his hips, traps and neck is going to be important for lasting the distance. Muscle slowing you down is an ancient myth that is dead in most sporting circles.
For one, its not gonna help him take a bodyshot and not gonna help his chin. May help him hold on the inside and you are flat out wrong about muscle slowing you down and affecting your power and stamina.
Athletes gain muscle to increase power. That's a well established scientific fact. It will only affect stamina negatively if it isn't done properly and something else has been sacrificed. Having muscle around the neck/traps helps to absorb impact and keep that area stiffer, that helps a fighters chin. Can't do much about bodyshots though.