Personally, I dont think Affeman actually believes Phil Heath is an average gym rat. Come on people, you don't understand sarcasm or hyperboles? Everyone is arguing like, "HE IS NOT AN AVERAGE GYM RAT" No shit, he isn't. Average gym rats weigh like 175 pounds on a good day.
But I think that shot just goes to show that if someone walked by him, they may not pause and be like, "HOLY shit, that guy is huge." If Ronnie was on that treadmill wearing a sweatshirt, you would still be able to see how massive he is. Not so much with Phil. A lot to be desired when he is covered up.