We’ve heard quite a bit about Natalie’s hectic training for Black Swan, and the name Mary Helen Bowers is often mentioned in association. Well, Elle have an interview with Mary and she gives some nice insight and details about Natalie’s training. Below is an excerpt.

How long did you work with Portman?
Natalie was very devoted to preparing for this role. She had a body double for some of the harder turning sequences but 90 percent of the dancing you see in Black Swan is her—even the upside-down splits! We started training at least six months before rehearsals began. We’d meet for five hours a day, six days a week. Even after filming started, we’d squeeze in sessions. Nat would spend 12 to 14 hours on set but we’d train in the morning and evening. It was a very intense time.