Pumping Up For The Part

Whether they're pumping iron for hours or scarfing down protein, here are some famous guys who bulked up and filled out for their roles.  Who do you think made the biggest muscle gains? Share your thoughts in the comments section.

To portray the boxing legend, Will trained with Darrell Foster, a longtime boxing trainer of the legendary Sugar Ray Leonard.

Speaking of gain, Wahlberg says he ate 10 meals a day and put on roughly 45 pounds for his role alongside Dwayne Johnson.

Compared to playing a slightly thinner Johnny Storm in Fantastic Four, Chris Evans had to sculpt his body in order to look like the perfect soldier.

When it came time to play Achilles, Brad Pitt took his famously lean physique and added more muscle mass thanks to a top-notch training regiment.

To look the part of the strapping comic book hero, Hemsworth spent hours in the gym to become as big as possible without losing his agility.

For the role of Bane, Tom Hardy worked out relentlessly for months in order to gain 30 pounds and fill out his costume, not to mention Bane's infamous face mask.

In order to become King Leonidas, Gerard pushed his body to the limit with the "300 Spartan Workout" which involved a brutal amount of various weight training moves.

Having already transformed his body for the previous X-Men films, Hugh Jackman may have had a slight advantage in getting even more ripped for his 2013 Wolverine movie, set in Japan.

To get those bulging abs for his role as Hannibal King, Ryan relied on a strict diet that increased his metabolism while taking creatine to build muscle faster.

His muscle gain for Batman was even more drastic since he'd just filmed The Machinist a year before, in which he played an emaciated insomniac.