In an article at WebMD talking about her charity work, Scarlett Johansson was asked about playing Black Widow in Iron Man 2.
“It was a whole new world for me, but I built a lot of strength, that’s for sure. Working on the wires and being suspended in the air, you throw one wrong kick or punch and, yeah, you’re out of whack,” she said. “But once you’re working with the stunt crew and they’re going through the craziest stuff, you feel bad about complaining that your knee has been blue for three months. The guys doing the stunts in those Iron Man suits, they can’t move in it and can’t take it off. I’d say, ‘Have you peed today?’ and they’re like, ‘No, we can’t move, we can’t take it off, we can’t drink any water.'”
The article adds that Johansson has signed to play Black Widow again in The Avengers, but that has yet to be officially confirmed.
Iron Man 2 opens in theaters on May 7.