The Sopranos star Michael Imperioli has found a way to quit smoking - take up martial arts. The actor, who plays mobster Christopher Moltisanti in the hit TV drama, insists he's healthier than ever, at 40, after becoming a fan of tae kwon do. He says, "I was in terrible physical shape. I smoked a pack (of cigarettes) a day." And he was so impressed with his tae kwon do lessons, he signed his wife and kids up for classes in Manhattan, New York. He adds, (It) has transformed our family in body, mind and spirit. It has changed us as human beings." The born-again martial arts fanatic admits his teachings have helped his acting too: "I have more focus, concentration and confidence."