9. Mickey Rourke - The Wrestler (2008)
In the performance that resurrected his career, Mickey Rourke portrayed another troubled Aronofsky protagonist in The Wrestler. Training for over 2 hours a day and eating constantly, the former real-life boxer claims to have gained 27 pounds in muscle alone. Rourke hired what was referred to as an Israeli cage-fighter to keep him on a rigorous exercise schedule. There are also rumors-- though none proven-- that like the character he portrayed in the movie Rourke may have dabbled in steroid abuse.