Yeah, there's something about that blowing up when they really step on the gas after becoming a Pro - the muscle looks sort of 'fresher' (nh) for a couple of years
I've noticed that -or something similar-, too. Both Derek and Nick both have an insane amount of muscle on their short frame and are probably on an similiar high level of PED use. However, due to Derek's not overly prominent vascularity he has some rather smooth (thus, healthy) look while the garden hose veins on Nick's arms and legs give the impression, there is an overpressure valve somewhere about to burst.