Zac Efron barely wears a shirt, so we know that he is very muscular. But up until this photo of him working his biceps, I never realized how Popeye huge his arms are. They are like muscles on top of muscles on top of even more muscles.
So why is he working on them now? Because if you are days away from working on a movie with The Rock, where the both of you are going to spend the whole time wearing only swimming trunks, you want to make sure your body is comparable. Although, there are very few men that can compete with Dwayne Johnson.
