Comedy star Seth Rogen is working out so hard to play comic book hero The Green Hornet, his exercise regime is making him sick.Rogen is switching from funnyman to action star in preparation for his new role as masked superhero Britt Reid in the big screen adaptation of the 1966 TV series.The movie is due to start shooting next February, but Rogen is already hitting the gym.He says, "I lost a little weight... I have a personal trainer now... it's really hard. I exercised to the point where he made me throw up."I thought he'd be kind of supportive about it - rub my back, or hold my hair out of my face. There was none of that at all. He seemed totally disappointed in me."But Rogen is convinced his dedication will pay off so he can prove others wrong. He adds of his 30-pound weight-loss: "I'll make a fine Green Hornet."

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