Jennifer Aniston says not exercising for Cake role made her grumpy

Jennifer Aniston’s getting some Oscar buzz for her role in Cake. Her character, Claire Simmons, is a car accident survivor with a scar on her face who suffers constant pain. To prepare for the role the actress stopped exercising for two months, and she tells Dr. Oz, that the lack of exercise took its toll on her mood.

“It’s interesting when you stop exercising. It really was interesting how my serotonin levels went down. My stamina was shot. I was cranky. I was irritable,” 45-year-old Aniston said. “I’m usually really not any of those things. I found myself short. I was hungry like crazy.”

Despite the obvious downsides of a foul mood, Aniston used it to help her play her role. “You realize exercise is just so important to our soul,” she told Dr. Oz. “Not just being able to fit into skinny jeans, to your state of mind, your soul, all of that. I surrendered into it. I actually didn’t fight it. I didn’t think oh this is horrible. It was such a part of what I enjoyed about mining this character.”

Cake is currently playing in select theaters, and will go into general release January 23rd, 2015.