by Tiffany Miles

Imagine being 25 years old forever. Doesn’t that sound glorious? But what exactly would you do with all that time? If you're Justin Timberlake and Amanda Seyfried, you run from a corrupt police force.

MTV recently caught up with the lovely Amanda at the junket for her upcoming thriller "In Time," and while chatting it up, the 26-year-old revealed the real-life hazards of running in heels, how her co-star saved her life and the tasty treat that kept her energized.

“Stunt heels are like three inches shorter usually, usually half the size, half the height of regular designer Yves Saint Laurent heels," she explained. "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."

What was Amanda's secret to keeping up with spry Justin during all those chase scenes? Donuts!

"He was running at like a 12.5 [miles per hour pace]. 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 fueled myself with donuts and everything was okay."

The star also admitted to refusing to film more takes of her running. "At one point I was just like, Andrew, I can’t. No, I’m not doing another take. I WILL NOT DO ANOTHER TAKE!"

Do you think you'd be able to keep up with Justin...while wearing heels? Tell us in the comments and on Twitter!