Hottest Bodies 2014

Sneak Peek: PEOPLE's Most Amazing Bodies of 2011

Kick off summer with a glimpse of Hollywood's sexiest stars in (almost) next to nothing!

ZAC EFRON

Topping last year's Most Amazing Bodies list, Efron, 23, isn't one to slack off – even managing to outdo himself while preparing to play a marine in an upcoming movie. "Zac put on 18 lbs. for his role in The Lucky One," a source tells PEOPLE. "Since then, he's lost weight but he's keeping up a fitness routine."