Ask Henry Cavill about the physical transformation he endured to pull off director Zack Snyder's "Superman" reboot, and he'll give you both sides of the coin.

"[The workout] was hell and wonderful at the same time," Cavill said. "[My trainer] Mark Twight (of "300" fame) gave me a whole bunch of workouts to do by myself to get my fitness levels up, so that when I arrived in L.A., the really hard stuff would start," the 30-year-old told Shortlist magazine.

Like Hugh Jackman did for "Wolverine," Cavill adopted a 5,000 calories per day diet in the beginning of his training to add 20 pounds of muscle to his frame.

"You’ve got to eat protein first, then a little bit of carbs … you’ve gotta keep your hunger levels going," he told Total Film. "I’m training two and a half hours a day, pushing my body beyond its normal limits, putting on a lot of muscle mass and just making myself look like Superman.”

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Once he added on the weight, Cavill said the hardest part of his training was sculpting it by reducing his eating regimen. "The leaning down phase is the hardest because although you're looking great, you're always in a bad mood because you're so hungry,'' he told Glamour.

After filming some shirtless scenes for "Man of Steel," Cavill says he took pleasure in dropping his diet and pigging out.

"The biggest treat was after a six-week phase when I was getting in shape for shirtless scenes," he told Shortlist. "After that, Zack Snyder bought me an amazing apple pie and a tub of ice cream. Then I ordered a pizza as well, and didn’t even go home — I just sat in a trailer afterwards and ate it. I passed into a food coma after that."

Interested in getting strong like Cavill did for "Man of Steel"? Some programs online that break down how to achieve similar results include good ones from Men's Health, Confitdent, MovieBody and FitMole.

Check out a trailer for the film below. "Man of Steel" hits theaters on June 14.

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Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Henry Cavill's 'Man of Steel' workout and diet
Actor says he consumed 5,000 calories per day to pack on more than 20 pounds of muscle for the latest 'Superman' reboot.