(Cover) - EN Showbiz - Natalie Portman is frightened of how easy she found it to deprive herself for Black Swan.

The actress has been praised for her portrayal of ballerina Nina Sayers in the Darren Aronofsky-directed thriller. She is hotly-tipped to win an Academy Award nomination for the part, which she spent more than a year training for.

Natalie had to learn how to dance for the role, and also went on a strict diet to ensure her body looked lean and toned like a ballerinas. Although she found the effort required tough, she was amazed by how easy it was to do without things she thought she needed.

I learned how much I could do. I think of myself as someone who seeks pleasure, doesnt like pain, so to actually put myself through pain for that long and not just make myself feel good, was a scary thing but also good to know that I could focus in that way for a role. It is frightening to know you can deprive yourself in that way, she told Cover Media. Absolutely I surprised myself. I dont think I expected how hard it was going to be and I feel lucky that I didnt expect it because I went in with all this enthusiasm and excitement about getting to do ballet and it really propelled me through all those difficult moments. Im not sure that would have been possible had I expected the hardship.

Natalie normally likes to leave behind the character she is playing when shooting has wrapped, but couldnt manage to do so for this movie. She still feels Nina is with her now, explaining certain things come into her mind at various times of the day or night which make her wonder if playing the character changed her personality.

I like to shut off and it was really difficult on this one. Probably because I had so much training outside of work to do that when work was done I had to go to the gym and then I had to wake up at 5am before work and workout before, it was constant throughout the day so there isnt really any time to just relax and be myself, she explained.

There are always little strands of your character that you dont even realise are in you that linger afterwards. I think because you have to internalise so much of what you character is going through and the way they think and see the world and the way they see themselves that it goes into your brain and body in ways you dont really understand until months and months later. This one was harder to shake than most because it was so all-consuming.

Black Swan is released in the UK on January 21. (C) Cover Media