Who can argue the convenience of a workout DVD? It's there when you need it, and in the comfort of your living room there's no competition for space and no shame in pausing for a bathroom break. But there is an obvious drawback: After watching the DVD a few times, you practically know it by heart, and so do your muscles. And boredom is the enemy of a good fitness regimen. Enter 1 Minute Workout, which uses the shuffle feature of your DVD player to create a new, customized routine every time you press play.

If you do the same choreography over and over, your body adapts to it so quickly," says the DVD's instructor, Minna Lessig, a former contributor to the CBS Early Show. "It's important to surprise your muscles."

Sorry, but the title 1 Minute Workout does not mean you can be done with your exercise in 60 seconds. It actually refers to the length of each of the 127 workout segments in the DVD's database, designed by Phil and Michelle Dozois. After doing one of the three 3-minute warm-ups, you select whether you want to work your upper body, lower body, abs or total body and pick level one or two. Finally, you're asked how long you want to work out, and choices vary depending on level and body part: For a level-one upper-body workout, you can select 4, 8, 12, 16, 20 or 24 minutes; level-two ab workouts range from 2 to 20 minutes; and a level-two total body routine can be between 12 and 72 minutes. Your player will shuffle the prescribed number of exercises, and — voila! — you have a fresh routine.