"It didn't look very good... I'm not very good at that stuff," he laughed to E! Online at South by South West, where he premiered his new movie War on Everyone.
"I took off and did a little bit of it and then I sat in my chair with my coffee."
One area where Skarsgard did excel was in building the body of a man who lives off the land and runs in the jungle.
"I basically had him (a trainer) and a nutritionist. I've never done anything like this before, this extreme. I was just really nervous. It was a big challenge and I didn't know how my body would respond to the training and diet," he explained.
The actor needn't have worried though. Promo photos for the blockbuster show him looking extremely buff, a necessity as he appears shirtless in the film - a lot.
His routine for months prior to and during filming included eating "a lot of chicken (breasts)" and completing many "crunches (sit-ups)", with just the one cheat day. But by all accounts his cheat day was well worth the wait.
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Skarsgard recalled his trainer taking him to lunch at an Italian restaurant in Notting Hill, London, and told him to order what he wanted.
"I started crying. He was like, 'Have pasta,' and I had it and then he was like, 'Are you still hungry?' I was like, 'Yeah!' He was like, 'Have a pizza then, have some tiramisu.' It was the best meal of my life," he grinned.
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- AAP
