Ever since she made her first film at age 12, Natalie Portman has thrived in challenging roles -- but none were so ambitious as Nina, the tortured dancer at the center of Black Swan. The ballet drama received a standing ovation when it premiered at the Venice Film Festival in September, with Portman's performance creating instant Oscar buzz. While in Venice, Portman began to open up about her excruciating training for the role. "Physically, I trained starting a year ahead of time, and then the six months prior to [shooting] the film, went into a sort of hypertraining, where I was doing five hours a day of both ballet and crosstraining with swimming," she told a room of impressed reporters. "It was very extreme, and the mindset during the film was just sort of extreme discipline and focus and obsession...which was fantastic."