Mark Ruffalo has received critical acclaim for his dual performance as twin brothers Thomas and Dominick in the harrowing HBO miniseries I Know This Much Is True . In addition to the usual green-screen acting challenges that come with playing multiple roles, Ruffalo created a clear physical distinction between his two characters; neurotypical Dominick is visibly thinner than his brother Thomas, who is schizophrenic.

Ruffalo has previously explained how he and director Derek Cianfrance agreed that he would shoot all of his scenes as Dominick first, and then put on 30 pounds to play Thomas, to illustrate the weight gain that many people experience when on anti-psychotic medication.

In a recent interview with The Wrap , Cianfrance said that Ruffalo lost 20 pounds first in order to play a noticeably thinner Dominick, and was doing “probably 500 pushups a day” during the first 17 weeks of filming. “My very first meeting with Mark, I told him that if we were going do something like this, I couldnt imagine us shooting in the morning, breaking for lunch and having him putting on a wig or a fake goatee and playing the second half,” the auteur explained.

“I just had this instinct one day when we were doing a phone call scene I asked Mark, I said, ‘Hey, could you do 50 pushups?’ Mark is the kind of actor where he’ll do anything. So he dropped to the ground, he did about 35 pushups, he came up, and he did this phone call scene and he was a little out of breath, you know? He was smoking these cigarettes and struggling for his breath a little bit, and his chest was puffed out, and I noticed the vein in his neck was engorged. We finished the scene and I was like, ‘Hey, let’s do another take. Can you do another 50 pushups?’ … All the time between takes, it was always our way to get Mark into the zone as Dominick.”

In addition to the daily pushups, Ruffalo also went on an extreme diet while playing Dominick, eating a maximum of 1,000 calories each day to aid his rapid weight loss a tough process which then informed his character.

“I guess you could say he was always a little bit hangry,” said Cianfrance. “He was eating an egg white for breakfast and just starving. And he couldn’t eat for another three hours, and all he could eat then was a granola bar that had 120 calories or something, because he was on this strict diet. It created this guy Dominick who was just wiry and aggressive.”

Source: MensHealth