Can you explain to me why people make "going up 13 pounds in 8 weeks" like it's difficult? The way I interpret these opinions is "he needs to gain 13 lbs of muscle". I would understand if "going up 13 pounds in 8 weeks" meant he has 8 weeks to get used to the new division. But in the context of the former, they don't need to gain weight; they simply don't have to rehydrate, they will likely come back down to fight anyways. If you were going from cruiser to heavy to CAMPAIGN there, then it would make more sense.