Mark Ruffalo begins work on The Avengers today, Friday April 29th, the same day his directorial debut Sympathy for Delicious opens in theaters. While promoting that drama, he opened up a little bit more about playing both Bruce Banner and Hulk.

When asked if he was, in fact, playing both parts, the actor confirmed that yes, he will be playing both Banner and Hulk. He also went onto describe what Hulk will look like when he appears on screen next summer.

"He looks just like me, but bloated and green. And big! He looks like me 40 pounds ago. [Laughs] I'm the first actor to do both. It's really cool. I was surprised by how well my theater training played into the motion capture thing, because it's all your imagination. When he moves across the ground, I want him using all fours, using his arms as much as his legs to move from here to there. I'd like to capture some of the primitive aspect of him. I've been working with [director/co-writer] Joss Whedon quite a bit on developing it, my portion of it. I'll be working with Robert Downey Jr., and I'm already doing the motion capture stuff. I'm excited."

When asked if he was bulking up to play Hulk, Mark Ruffalo said quite the contrary.

"The more of a difference there is between Mark and the Hulk, the happier everyone seems to be. I was like, 'So do you want me to get ripped up?' And they went, 'No, no, no, no, no, no! Nice and trim. We want you nice and trim.' They said, 'We want you to look good with your shirt off, but we don't want you strapped.' I can live with that. And so can my wife!"

The Avengers is now shooting in Albuquerque, New Mexico.