Body of Work: The Top 20 Fitness Icons

The Troop Leader: Michelle Obama

Even though the 48-year-old mother of two gets up at 4:30 A.M. to work out, first lady Michelle Obama is amused by the media attention her buff-itude attracts. Her first major initiative, Let's Move, launched in 2010, is aimed at fighting childhood obesity by encouraging kids to exercise and eat food that comes out of the ground rather than a vending machine. To underscore her seriousness, she took on TV hosts in push-up contests -- and won. "I'm pretty much willing to make a complete fool out of myself to get our kids moving," she has said.