HiiT stands for "High Intensity Interval Training" and is hands-down one of the best ways to burn fat without causing your body to catabolize your own muscle tissue.

The HiiT workout DVD features three different high-intensity routines that are each 30 minutes or less, making these workouts perfect for you to use on days where you're short on time.

The first HiiT workout is 30/30, and as the title suggests, each interval is divided into 30 second high energy plyo reps, followed by an equal 30 second rest for a total of 16 tough intervals.

The second HiiT workout is 40/20 divided into 16 intervals. Each interval is divided into 40 seconds of high energy plyo reps, followed by a 20 second rest. Three additional one minute breaks are spread throughout the program.

The third HiiT workout is Double Wave Pyramid. In this workout are two rounds of intervals separated by only a one minute rest. In each round is a pyramid cycle of nine intervals, in which the first set starts with a 20 second interval, and works up to the top of the pyramid, increasing each interval by five seconds. The workout then works back down the pyramid decreasing each interval by five seconds.