Four 12-minute abdominal routines, each with a different toning style — or they can all be done together for a 36-minute workout. Chris Freytag is the instructor.

Beginning and advanced beginning exercisers. You'll need a mat and for the final routine, a stability ball.

When you're doing abdominal exercises on your own, it's easy to get into a rut. DVDs like this one are good to have around so you can change up your routine when you've done one crunch too many. With The Abs Advantage, Chris Freytag gives you four very distinctive ab workouts. Each is 12 minutes long, which includes a 2-minute warm-up and a quick, 2-minute ending stretch. The first routine is based on Pilates moves (although it's done with your athletic shoes on). Workout number 2 gives you core exercises, both standing and on the mat. The third routine is called "classic abs," but it offers up quite a few challenging variations on the traditional crunch. The final segment tones your abs with the help of a stability ball. All routines include easier and more advanced modifications. You can choose just one routine, or you can do all of them for a full, 36-minute workout (the warm-up and cool down are done just once, which is why you shave 12 minutes off the combo). These workouts are best for beginners and advanced beginners. The first two especially may not be quite challenging enough for intermediate exercisers, unless they a) always do the advanced modifications and b) really focus on the muscles being worked, especially the transverse abdominus. The last two workouts are more challenging, and you intermediates will probably get a satisfying workout if you do these two together, or choose the full four-routine workout. Chris Freytag, as always, is an excellent instructor. She has good cueing and a great attitude. The only thing that could be improved about this DVD is its programmability — it would have been nice if it were possible to choose two or three workouts in an order of one's own choosing, without having to repeat the warm-up and cool down every time. As it stands, you have to do one workout at a time, or all of them — no in between.