Three well-structured aero/tone interval workouts led by “The Biggest Loser” trainer. These fast-paced exercises will keep you burning fat as you sculpt muscle. The programs build in intensity; you can start with the intermediate level and work up to the advanced program (it’s tough! — moves like plyo-lunges and traveling pushups). Each workout has three “cycles.” Each cycle starts with three minutes of multi-muscle and isolated strength training. Then it’s two minutes of non-dancy kickbox and athletic-style cardio. That’s followed by one minute of classic abwork (then — no rest — you’ll immediately start a new cycle). Like on the TV show, Jillian is both demanding and supportive. Requires 3 to 5 lb. dumbbells.