(Cover) - EN Showbiz - Natalie Portman has revealed she has a newfound respect for ballet dancers.

The actress has been gaining positive reviews for her role as a ballerina in Darren Aronofskys new thriller Black Swan. The stars performance was all the more extraordinary when she revealed her punishing work schedule. The 29-year-old has previously spoken of 16-hour working days coupled with a daily maximum of four hours sleep maintained throughout filming. In addition Natalie also had to learn the art of ballet.

"It's a very disciplined environment and the physical training was intense. All that pain and rigor bleed into the character. I have a newfound respect for ballet dancers," she told Extra magazine.

The films director has also confessed he was often worried about the actress during some of the tougher scenes. Darren was impressed by Natalies dedication to the role and says her hard work paid off.

"I was a little nervous for Natalie. It was a tall order to fill, and she was eating carrot sticks and almonds for a year but her performance was amazing, Darren revealed.

Black Swan which also stars Winona Ryder and Mila Kunis focuses on a relationship between a veteran ballet dancer and her rival. (C) Cover Media