Paul had an unbelievable response to AAS and GH, truth is as big as he was, he never ate much, sometimes as little as once a day with a few shakes. Plus he never trained heavy or overly hard, might look like nothing off sauce, but his genetic response was something else.
Similar could be said for Flex and Kevin, guys went from skinny fat to huge in no time, only trouble was there was a certain english guy who had all that and then some and instead of taking time off he just kept going and come olympia day you could tell the difference between who trained all year and those who didn't.