Black Swan's Natalie Portman- CNN

Living a role for a movie is hard work -- living the physically punishing life of a ballet dancer is even harder. But it's worth it when you get awarded with a Golden Globe for your efforts.

Actress Natalie Portman -- who Sunday won a Golden Globe for her performance in Darren Aronofsky's "Black Swan" -- went method for her role as tortured ballerina Nina Sayers.

Though at a press conference in London she said she was more of a "pleasure-seeker" than a "self-punisher," Portman described the grueling training she underwent for the film, and how mid-way through shooting the film she suffered a dislocated rib.

"Black Swan" is set in a fictional New York ballet company, where highly strung young women battle it out for star roles. Portman plays a corps dancer given the role of a lifetime: that of the Princess Odette in Tchaikovsky's classic ballet, Swan Lake.

But not only does her character have to portray the good princess Odette, who is turned into a swan by an evil sorcerer; she also plays the sorcerer's daughter Odile, the black swan of the film's title.

Dancing as the two swans proves psychologically unsettling for Sayers, a good girl required to turn bad for the role of Odile. She is goaded by the ballet company director (played by French actor Vincent Cassel) into exploring her dark side for the role.