Lily James got into shape by pushing a Smart Car round a car park.
The 'Downton Abbey' actress stars in the upcoming film 'Pride and Prejudice and Zombies', which is a stark contrast to her usual period drama roles.
In order to shape up for the film, which has some very physically demanding scenes, Lily was put through her paces by a personal trainer.
She said: "I had just been doing 'Downton Abbey,' where you don't have to exercise at all. You just drink tea and eat biscuits, so I had to get really, really fit. "I had this amazing trainer. He had me pushing a [Smart Car] around a car park and doing like martial arts and boxing and stuff."
Lily added that she finds the tale, based on the book of the same name, "refreshing" as it sees the women take charge.
She added to HuffPost Live: "I loved the fighting in this, especially because it was all girls. It was the Bennett sisters that do all the bulk of the fighting. It's like a real feeling of girl power and that we are the ones saving the day and saving the men, and that's really refreshing.
"We were in the corsets and look sort of like these gentle girls, and then suddenly, when it got to it, we were like so fierce and like a pack of wolves. And I think strength is always sexy."