Cena is in this issue of Flex magazine where he states that his weight lifting routine consists of only deadlifts, pull ups, and push ups. Yet, he has amazing muscle mass for such a crappy routine. You see, the routine may target all the muscles, but in order to gain mass like Cena has, you need to add weigth resistance, you don't have weight resistance with pull ups or push ups, how is he so big then, and he also states that he only takes whey protein power.
He must take steroids, steroids bulk you up, and with Cena's routine, he will only be shaping his muscles, and making him stronger, while the steroids make him big.