Pitt Kicks Butts For Troy Role

Brad Pitt as renowned warrior Achilles in "Troy."
To play the Greek hero Achilles in "Troy," the most physically demanding film of his career, Brad Pitt gave up something he loved: smoking.

"This guy's supposed to be the greatest warrior of all time; I had to get my (butt) in shape," Pitt tells Vanity Fair magazine for its June issue. "I changed my life completely. I quit smoking, and let me tell you, I was a professional smoker and I still miss it. ...

"But I wanted to see how far I could go with my body," he adds. "By the time the movie was over, I'd been on this diet and workout plan for a year."

Something the 40-year-old actor hopes to add to his life: children with his wife, Jennifer Aniston, which has become a topic of rampant media speculation.

"It will happen when it happens," Pitt says.

"I've got friends with kids, and I've got nieces and nephews, and they just bring out a joy I've gotten from few things. I am selfish, so I worry about having to give up my time, but I gotta go see what it's about," he says. "I think I've got a lot of stuff to tell them, and the idea of being responsible and setting someone loose in the world sounds really fulfilling."

"Troy," directed by Wolfgang Petersen and co-starring Orlando Bloom and Peter O'Toole, opens May 14.