22 Unbelievable (and Crazy) Movie Transformations (PHOTOS)

Brad Pitt has never been a slouch when it comes to working out, but when preparing to play Achilles in the 2004 epic Troy, he went all-out. And holy abs did he get results. The heartthrob gave up cigarettes and cut way back on the beer and chips, opting for a low-carb, high-protein diet instead. His year of brutal training, which involved running, yoga, weight lifting, and sword work, produced a beautiful specimen of man with the face of Brad Pitt and the body of a Greek god.

"I wanted to see how far I could take it," he explained to People. "I was turning 40 [last December], and I figured there was an impending midlife crisis on its way." (He said that just half a year before leaving Jennifer Aniston for Angelina Jolie. Prophetic? Indeed.)