Stars' Summer Style

Bell's defined stomach didn't appear on its own, and it's a new development, Bell says. "I have never had abs like this from sit-ups." So what's her new secret? Boxing. "I love it! It's a whole body workout and it lets out aggression that I didn't know I had." And the repetitive hooks and jabs paid off. "You're doing the motions over and over and you don't realize how much you activate your core."