Baggy's power is highly limited after slimming down, his strokes are less harmful than a decent WTA shots. I think Del Po should be able to overpower Marcos, and it won't take 5 sets.
Do you REALLY think this applies to men as well?
I know in the past women have gotten fitter and lost pace on their strokes, it doesnt seem to affect men the same way.
Fish comes to mind, as well as Roddick, even though in ROddick's case he seemed to have lost all his ground stroke pace after his US Open win.