Behind the Scenes with Jillian Michaels: A Fitsmi Exclusive!

Jillian Michaels knows better than anyone what it's like to be a fat kid. Hard to believe, maybe, looking at her rock hard, 115-pound, 5'2 and a half-inch physique. But it's true--as a teenager, Michaels, now 37, once weighed in at 175 pounds. She credits martial arts with helping her slim down--and a drill sergeant teacher with inspiring (read: terrifying) her to Get Serious. "I was being more active but I was still eating like s*** and my martial arts instructor gave me an ultimatum where...