12/27/2012 10:58 am ET

Hugh Jackman's Workout Revealed: How The Actor Prepped For 'Les Miserables'

Hugh Jackman is known for being pretty jacked (sorry), but his turn in "Les Miserables" presented some new difficulties for the actor. As Jean Valjean, Jackman had to play a man that was well-built but suffered greatly throughout his lifetime -- and thus had to fluctuate his weight accordingly.

The "X-Men" star revealed his workout regimen in a recent interview with Vulture, noting that Valjean was "more physical" of a role than Wolverine:

I had never thought of Valjean as a particularly physical role until I saw this film. It looked arduous.
Weirdly, this was almost more physical in a way than an "X-Men" movie! I was spending even longer in the gym — like three hours in the gym — because I needed to be as emaciated as possible, but still keep some muscle on for Jean Valjean. He's actually written as an ox of a man, so I had to eat seven times a day with no carbohydrates, but then you had the exercise. I'd wake up and do 45 minutes of card on an empty stomach, eat something, go to the gym, do a vocal warm-up, and then after lunch I'd go back to the gym again. Otherwise, I'd just become skin and bones.

Jackman wasn't the only "Les Mis" star to put his or her body through the ringer. Anne Hathaway, who stars as Fantine, lost a good amount of weight for the film. The normally slight Hathaway told David Letterman that she shed 25 pounds for her role as a factory worker turned prostitute.

The cast's hard work appears to have paid off: "Les Miserables" took in a strong $18.2 million at the Christmas Day box office, the fourth-largest Christmas gross of all time.