True, but the joke was Vlado Szabo. (The guy's record was literally something like 1 - 30) Also, 275 IS heavy for Larsen. Not horribly so, but it shows that he's not totally serious about training for this fight, even though it's the most important fight of his life. What does that say?
Yes, but extra fat puts a lot of strain on the heart, because fat cells have a lot more capillaries than muscle cells. It takes a lot of energy just to pump blood through them. So, ten extra pounds of fat can cause a fighter to gas out in the later rounds.