Natalie Portman Talks Black Swan Weight Loss

Actress Natalie Portman had to drop a whole lot of weight for her role as a ballerina in upcoming psychological thriller 'Black Swan.'

The 29-year-old actress shed 20 lbs off her petite 5'3" frame after a year of intense training which included swimming, cross-training, and endurance exercises.

"I had never gotten that much training - to be doing five-to-eight hours a day of [it] was really a challenge," Portman said of losing 20 lbs.

"I think the most important thing is coming to work as prepared as you can be every day and working as hard as you can every day. If you do that, you can always ensure that you have an amazing experience," Portman added.

Mila Kunis and Natalie Portman at the premiere of Black Swan

Under the guidance of former professional ballerina, Mary Helen Bowers, Portman trained for up to 8 hours a day with only one day off per week. "The goal was to create a very long, lean ballet-type body," Bowers, told UsWeekly. "We combined swimming a mile a day with two hours worth of Ballet Beautiful exercises, toning, and resistance work. And another 3-plus hours of ballet class and point work."

Black Swan is a ballet thriller by director Darren Aronofsky in which two young ballerinas, Natalie Portman and Mila Kunis expand their rivalry into a twisted friendship.