(Cover) - EN Showbiz - Emily Blunt says her back looked like a barrel of snakes after she transformed her body for her new film role.

The British actress plays a ballerina in the upcoming thriller The Adjustment Bureau, and worked hard to alter her already svelte physique so it was more of a dancers shape.

The 27-year-old has never had any formal dance training, so took on the challenge of learning ballet alongside memorising the movies script.

I looked like an aerobics teacher, the actress told the March issue of Womens Health. My shoulders puffed out, my back looked like there was a barrel of snakes in it and I had an eight-pack.

The brunette beauty who famously shed weight for her Golden Globe-nominated role in The Devil Wears Prada is on the cover of both Womens Health and Mens Health with her co-star Matt Damon.

I met Matt and he was lovely and very funny, and instantly I thought, Oh we could be like teenage boys together, she told the male publication.

Matt, 40, was interviewed alongside Emily, and raved about working with her. He couldnt believe how fun she was to be around, likening their friendship to the relationship he has with best pal Ben Affleck.

"When [Ben or I] comes up with an absolutely f**king horrible idea, which happens all the time, the other person, without batting an eyelash, says, 'That's a terrible idea,'" he said. "And neither of us has our feelings hurt, and we just kind of move on. (C) Cover Media