8 actors who transformed their bodies for roles

From bulging muscles to skin and bones, the physical metamorphosis of Hollywood stars is an art all its own.

9 / 9

Man of Steel Man of Steel (Photo: Man of Steel)

9 / 9

Henry Cavill for "Man of Steel"

What does it take to become the most powerful superhero in the universe? About 11 months, 6 workouts per week, 5,000 calories per day, and a ruthless Hollywood trainer. Oh, and the genetic disposition of British actor Henry Cavill.

The 32-year-old completely transformed his body for the 2013 reboot "Man of Steel," packing on 20 pounds of muscle with the assistance of legendary trainer Mark Twight. Cavill trained for 2 1/2 hours per day, pushing his body beyond his normal limits with an extremely challenging Olympic weightlifting-based routine.

By the time "Man of Steel" started filming, Cavill weighed about 190 pounds, with an average of 5-7 percent body fat. How did he celebrate after completing the shoot? With a well-deserved apple pie, pizza and a tub of ice cream. "I passed into a food coma after that," he said.

Photos and SlideshowsPhotos and Slideshows