Your pencil art submission is jaw dropping, man. But I do have one problem with it ... (After agreeing with what Ratty said)
HIS left pectoral seems to be flexing. I've been telling myself that's because his left arm is turned towards his body causing a number of antagonistic movements to occur, But I feel it's a little exaggerated. If you have noticable pectorals yourself, Do the motion that he is doing and examine the muscle movements. Our body's muscular system works together as a team, If one muscle moves, So do the surrounding muscles to make that movement possible.
You're so fucking good at this, though. Man I'm jealous!