Wow! That's actually kind of impressive!
His skin looks surprisingly tight. Obvious distended abs, but holding on to some muscle especially in chest and back, and extremely low fat percentage.
First, Im assuming he never got stupidly huge. Built slow and steady, not a lot of weight fluctuations, probably very consistent diet year round, probably medium weight, moderate intensity, volume, and exercises outside of bodybuilding, like bodyweight exercises, tumbling, gymnastics?
What do you suppose this guy took to get in this kind of shape? HGH? And???