The actress explained that movies such as James Cameron's Avatar have taken their toll on her body.
She told Total Film: "I always go home looking like a map. That's what my mum tells me because I have black and blue all over the place. But I'm addicted to the adrenaline of being a physical person.
"That said, I'm entering the consciousness of mortality. With Avatar I was fine; I'd get hurt, I'd get up, I'd brush it off and keep going.
"But my body feels like it's aged ten years. It can't reboot as quickly."
The 33-year-old has recently finished filming the movie Colombiana, in which she plays a steely assassin, and is reportedly being considered for a role in art heist thriller Trance.