Zac Efron Videos: Talk about 'Charlie St. Cloud': Zac Efron's ghost-whispering role in "Charlie St. Cloud" didn't earn him any Golden Globe nominations, but the actor still showed up to support his Hollywood peers at this year's awards. And for us, it was the perfect chance to ask him about his part in the upcoming military film "The Lucky One"—particularly about his, um, guns."I knew that, the second I went to camp and met some real Marines, that I didn't have that presence that they possess," Zac told us.

And by presence, of course, he means massive, writhing muscles. "They have this way about them, and they're like 50 lbs. heavier than these guys," he explained, indicating the lithe and lean crowd of actors milling around behind him. "I started training immediately, to do the best I could.

But while the rocking bod Zac developed in order to play the role was a nice bonus (and we do mean nice—have you seen these production photos?), he tells us that it was respect for his character that drove the transformation. "Its a part that's kind of sensitive," he explained. "I cared too much about it to just let it slide, so I really put in the work."