AceShowbiz - Mark Ruffalo is adjusting well to the grueling training he is undergoing for his shirt-ripping new role as The Hulk - because he was once a high-school wrestling champ. The 42-year-old actor is set to replace Edward Norton as Dr. Bruce Banner and his monstrous alter-ego in upcoming superhero movie "The Avengers, and is already eating plenty and working out to get in shape.

But Ruffalo has been through the pain of toning up his body before - he followed in his dad's footsteps and won medals as a student wrestler. He tells E! Online, "They (film bosses) want me mean and lean, but they don't want me big and buff. I gotta keep building and building and building. You have to eat to build muscle."

"I was a wrestler. I'm used to starving myself. It's easy for me. The last two weeks you just walk around spitting into a cup."