B True,
More muscle moves more weight but that doesn't mean more weight grows more muscle. None of the guys that I've seen at WSB have particulaly good physiques. (Not that they care. Again, their thing is lifting X amout of weight from point A to point B) They're just big guys with naturally dense bones and great tendon and ligement insertions. Compare them to a guy like Serge Nubret who did curls with 25 pounds for 15 sets of 15 reps. Paul Dillet also trains light and he seems to have put on a bit of muscle. Growth is about stressing the muscle -- which can come from more weight, speed, duration of rest between sets, more volume, or more intensity. But it never comes from momentum. That just lessens the stress.