Ashton Kutcher: 'Cameron Diaz Is Fitter Than Me' 5/6/08

Hollywood actor Ashton Kutcher struggled to keep up with his What Happens In Vegas co-star Cameron Diaz on the set of the movie - as she is much fitter than him.

The 30-year-old vowed to start a healthy new exercise regime ahead of working with the Shrek star, as he had heard the actress was a keen gym-goer. But Kutcher was still amazed by Diaz's high level of fitness when the pair finally met and admits her athletic abilities put him to shame.

He says, "Before I started the movie I worked out with a trainer because I couldn't have my leading lady be in better shape than me. "Cameron gave me such a tough time. She'd say, 'Are you still working out?

Because I already worked out hard this morning.'" And Kutcher insists that all the fight scenes in the movie are real, and Diaz was more than able to hold her own. He adds, "She's a tough chick. She went for it - it wasn't fake. I got beaten up a little bit, but not too badly."