(Cover) - EN Showbiz - Mark Ruffalo has been told to get mean and lean for his role as The Incredible Hulk.

The 42-year-old actor has followed in Edward Nortons footsteps and will portray the muscle-bound green mutant on the big screen in The Avengers movie. Although Mark thought he would be expected to bulk up for the role, director Joss Whedon has instructed him to follow a precise exercise and eating regime so he achieves the ideal body shape.

"They want me mean and lean, but they don't want me big and buff," he told E! Online.

The star will be doing gymnastics, Pilates and Tae Kwon Do in order to get in shape. Mark has also revealed his sporting past will help him with his eating plan and he is well aware of what it takes to build up muscle and still stay trim.

I gotta keep building and building and building. You have to eat to build muscle, Mark added. "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."

The Avengers is due for release in 2012 and will also star Robert Downey Jr., Scarlett Johansson, Samuel L. Jackson, Chris Evans and Chris Hemsworth. (C) Cover Media