walt
DuffProteinMan
Lets be clear here, Some of them may have done powerlifting style training very early on and everything else in between however, their physiques were built with bodybuilding.
Arnold didn't get the pump by doing 3 reps
I think it was the 50's or 60's when bodybuilding wasn't really a sport and was performed after the weightlifting, so the bodybuilders at that time all were quite strong because they had to be for competition.