The competition "World Strongest Man" the world championship if you will had some kind of testing. A polish guy finished third but was disqualified later when the drugtests were in.
I think this is different depending on what competition you look at.
Its completly plausible that there are men with genetics generous enough to allow performance like the strongman competitors.
Guys with low bodyfat, small wrists and small ankles that still have the muscular development to compete on an elite level are defying the bell curve more then their big boned collegues.
They are the ones that most likely juice. Like the polish guy that got disqualified.