Truth. Ever hear the term "there's no replacement for displacement"? In that term the word "displacement" is referring to size of the engine. The bigger the engine the more power and torque is produced, but also the more gas needed to produce it. For most people, the bigger their muscles the more energy it takes to power them. If a fighter has primarily fast-twitch muscle fibers and they are very muscular -- they will gas out quickly if they dont conserve energy. They are typically the guys that if they get someone hurt, they go ballistic looking for the kill and if they dont get it, they blew their wad and are likely to get hurt/stopped themselves.
Some muscles can be built up of prominently of slow twitch muscle fibres. Take Joshua for instance. In the first fight against the blob Ruiz. He was 247lbs. His muscles was rock solid and dense. He then did more high rep exercises. And dropped to 237lbs, but he was still muscular, his muscles were soft and he wasn't as ripped however. I'm exactly the same when I cycle between low and high reps. The muscle size is a illusion, you can be physically as big, but still be lighter on the scales, if it's water muscle. ( sarcoplasmic) I personally stay away from all low rep strength based training, I find it messes with your stamina, and mobility.
Marathon runners are at the extreme end of the stamina spectrum with little muscle mass. Conversely body builders have very little stamina. Muscle mass decreases stamina because muscle is heavy and needs energy to be carried around. Boxers need to balance stamina versus power. E.g AJ went for stamina in the second fight with Ruiz, who went with power. It worked out for him as he was able to stay clear of danger and outjab his way to victory. I feel boxers these days focus more on power and cut corners in terms of stamina, using dodgy weight cutting regimes to cut weight instead of the more traditional cardio.
Its because your muscles adapt to the higher reps and a lot of that size and weight is going to stored energy -- glycogen, and protein.
In general, yes. But, they've got an app for that. Get on the right PED's and you can be a bulked up volume puncher, too.
Agree with poster above. Muscle mass does effect stamina but nowadays peds are helping to negate it a lot more.
Modern rugby is a good example they are huge but although they are explosive runners you wont see them working hard for the full 80 minutes
