This fat-blasting workout led by fitness icon Denise Austin offers all the benefits of a raging house party without the dread of a next-day hangover and trashed living room. In the first high-energy session, you'll do 20 minutes of cardio via an easy-to-follow routine that incorporates the cha-cha, the mambo and the twist. In the final segment, you'll lower your heart rate but ramp up your muscles with a series of body-sculpting exercises.