Oh, I agree, they just don't normally have perfect human bodybuilding biceps and triceps and forearms like in the stills.
But I can be totally wrong as well. Weirder shit is out there. One thing with videos like that, when a subject fills almost the complete frame, one can no longer have a reference to judge size and such.
But lets not bring in the 8 foot tall at the shoulder dogs and oinkers.