(Cover) - EN Showbiz - Amanda Seyfried admits that wearing heels while performing stunts is "tough".

Amanda stars alongside Justin Timberlake in science fiction thriller In Time. The film involved shooting rigorous action scenes.

Amanda felt her costume cumbersome at times while filming these intense sequences.

"Stunt heels are like three inches shorter usually, usually half the size, half the height of regular designer Yves Saint Laurent heels," Amanda explained to MTV News. "They were great shoes in the movie. It's tough. At first I took a big spill, which if it weren't for Justin it might have killed me."

Amanda also found it difficult to keep pace with her swift co-star Justin. She felt as if she was sprinting after him at times.

"He was running at like a 12.5 [miles per hour pace]," Amanda explained. "Yes! I asked the guys in the truck with the camera how fast they were going. He's like, we're going like 12. I was like, Justin runs that fast. I don't! Trying to keep up man, seriously. I just fuelled myself with donuts and everything was OK."

The actress was so fatigued at points that she could not run anymore.

Amanda butted heads with director Andrew Niccol when she wanted to give her tired feet a rest.

"At one point I was just like, Andrew, I can't. No, I'm not doing another take. I WILL NOT DO ANOTHER TAKE!" Amanda laughed.

In Time will be released in US theatres tomorrow. (C) Cover Media