"I had never done anything as physical as this film and it required more than I ever expected," she told HFPA members when she met them at the SLS Hotel in Beverly Hills.
"It was fantastic to be able to play a very strong, capable woman in what could be considered a very male-centric film.
"I was never in that shape before and I'll never be in that shape again."
But, she confesses, throughout the filming she was dreaming of the meal she would have as soon as shooting wrapped.
"I'm married to an Italian and I love pasta and red wine but I couldn't have any until filming was over," she said.