Matt Damon has certainly seen his fair share of weight loss and gain for movie roles.
So when director Neill Blomkamp told the Oscar winner he wanted him to bulk up for his role in Elysium, he was ready to put in work.
Like, four hours a day in the gym, type of work.
"[Neill] was so specific about what he wanted me to look like. He actually had a picture with my face tacked onto this guy with this body, and they literally hired me a trainer and I went to him with the picture," Damon explained to Variety. "It was four hours a day in the gym -- and I'm not 26 anymore, but I got in shape."
Indeed, in trailers for the film the star looks much hulkier than his most famous action film character Jason Bourne.
But the new very muscular figure is much less shocking than the overweight whistle-blower he played in The Informant! Of course, for that film he says transforming his body was a total breeze:
"It was very, very easy to gain the weight. Very, very fun," Damon told Access Hollywood in 2009. "I just basically ate everything I could see for a few months."
Mind you, packing on the pounds is a lot less hard than losing 50 lbs, which Matt famously did for his role in 1996's Courage Under Fire. For that military drama the actor ran more than 12 miles a day and his starving diet consisted of chicken breast, plain baked potatoes and egg whites.