The system can come up with so many different permutations that it's safe to say you won't do the same one twice. But it's not so random that you'll be jumping from bicep curl to bicycle crunch and back — the order of the types of exercises you do is predetermined. In any given level-two upper-body workout, for instance, the DVD will give you two chest exercises, two back exercises, two arm exercises and one total body exercise before repeating again. (Note: You should have two sets of weights available: one set of two to three pounds and one set of five to eight pounds.)

Say one day you have half an hour of workout time to squeeze in before dinner. After the warm-up, you can do a level-two 20-minute lower-body workout — side lunge with arm reach, squat with calf raise, leg circles, plie; squat, stationary lunge and leg lift, lying-down front leg kick, single-leg squat, squat with feet together, side-lying knee-to-heel tap, side squat and about 10 other exercises, followed by one of three 3-minute cool-downs. If you have just a few minutes, the 4-minute lower-body routine can be alternating reverse lunge, squat with feet together and kneeling leg abduction. If an exercise happens to repeat within one routine, you definitely won't mind, since the sets are so short. When the burn kicks in, it's such a relief to know you'll be doing something else in a minute. Moving quickly from exercise to exercise keeps your heart rate up as well.