Time Spent Preparing: One year Before she even had a script, Natalie Portman was getting physically prepared for Black Swan. In Darren Aronofsky's nightmarish ballet drama, Portman plays a dancer obsessed with achieving perfection, so the actress decided she would follow suit and make not putting a foot wrong as a ballet dancer her priority. According to Aronofsky, Portman was in dance training for a year before shooting began, paying out of her own pocket for most of it. She was also working out for five hours a day to attain the right body type in the run-up to the shoot, as well as swimming a mile a day and taking choreography lessons as filming drew closer. Portman lost 20 pounds as a result. She also altered her own voice during her year of preparation, with the actress working with vocal coaches to regress her backwards to the point where she had more child-like tones.