Mila Kunis underwent a serious training programme to prepare for her new movie Black Swan and she admits that her instructor 'kicked my ass'.
The actress stars alongside Natalie Portman in Darren Aronofsky's latest movie Black Swan, which sees the two women take on roles as ballerinas.
So to prepare for the movie Kunis has to get into shape as well as take on ballet training.
Speaking to MTV the actress said: "The preparation was, get as skinny as you possibly can as fast as you can and then learn to get en pointe while doing it.
"I got the part, let's say on a Wednesday. Thursday morning I went into the ballet studio in L.A. with Alexandra Blacker who was my ballet instructor.
"[She] was 20 years old at the time and had already broken her back and had fractured ribs and things. I went in there, started working with her for seven days a week, five hours a day and was put on a 1,200-calorie diet for a total of five or six months.
"I did get one day off, and that was my birthday; Alexandra made me a root beer float. She never gave me a break. She was 20 and she kicked my ass."
Black Swan is released 21st January.
Tagged in Mila Kunis