The hardest thing about playing a superhero is that you've got to look the part. Ask Scarlett Johansson.

The actress had to whip herself back into shape to reprise her role as Black Widow in "The Avengers," which opens next Friday (May 4th).

"Every woman has body worries," she told ITV1's "Daybreak" morning show in the UK earlier today. "I'm not exempt from that. But beyond part of the by-product of spending that much time in the gym is that you can fit into a cat suit."

Beyond sheer looks, another reason Johansson had to get into supreme shape is because she did a lot of her own stunts in the film. She worked with stunt double Heidi Honeymaker on pulling them off.

"The idea is that she (Moneymaker) and I become one and we can start and finish each others moves and everything in between," she said. "And it's a lot of training and dedication and it hurts and it hurts and it hurts and then suddenly it doesn't hurt and you're getting it right and it's a great moment – you feel like you’ve accomplished something big.”

[PEOPLE]