March 7, 2002 -- They're everywhere. You can hardly turn on a TV lately without stumbling across infomercials offering a belt-like device that promise rock-hard, six-pack abs without exercise or dieting.

"It would be nice if you could get the kind of muscle development you see in these ads with a simple, electrical device, but you can't," says Kiku Trentylon, a fitness trainer in New York City. "They're selling a fantasy."

But it's an enticing fantasy, and one that is attracting many eager buyers, as sales of these electrical muscle stimulators (EMS) are reported to be brisk.

"The electrical muscle stimulators advertised on television are another attempt to mislead the public into thinking that a simple device can create the perfect stomach," says Robyn M. Stuhr, MA, of the Women's Sports Medicine Center Hospital for Special Surgery in New York. "They may improve muscle endurance, but only in one position. And regardless of the type of abdominal exercise performed, if an individual has a thick pad of fat, they won't see 'six-pack' abs no matter how many repetitions or minutes they spend on their abs."

Despite numerous skeptics, EMS devices have supporters in the medical community. Michael J. Skyhar, MD, a sports orthopaedic surgeon and a staff member of Damluji Research of San Diego, is a spokesperson for Electronic Products Distribution, maker of the Ab Energizer.

"Electrical muscle stimulation is well established in the medical literature as having therapeutic benefits," says Skyhar. "It's a comfortable, safe, and simple way for my patients to strengthen lower back and abdominal muscles."

But the high visibility these products get on TV and the sweeping claims made about their effectiveness are bringing them under greater scrutiny.

Now, the FDA is reportedly looking closely at the claims made by the makers and sellers of these devices to determine whether rules about making unsubstantiated medical claims are being violated.

Let the Buyer Beware

"When someone tells you they will sell you something that will turn you into a he-man overnight, you should be very, very skeptical," says Stephen Rice, MD, PhD, who specializes in sports medicine at the Jersey Shore Medical Center in Neptune, N.J., and is a spokesperson for the American College of Sports Medicine.

But even if the devices sold on TV can't do what the sellers promise, EMS itself isn't at all hokum, says Rice. EMS devices are an important part of physical therapy for people recovering from certain types of surgery or injury. Among other legitimate medical uses, physical therapists can use EMS to prevent a patient's muscles from shrinking during a long recovery after an accident, for example.

"For the average couch potato who may be getting no exercise at all, these devices may provide some muscle tightening and improved muscle tone," says Rice. "But that will not transfer to the kind of strength for real-world results needed in sports or in some occupations. And it will have no effect on reducing body fat."

To lose fat around the stomach, diet and exercise are still the only useful options, says Carl W. Nissen, MD, associate professor in the departments of orthopedic surgery and sports medicine at the University of Connecticut Health Center in Farmington. "You'd be better off spending your money on good nutrition and a health club membership."

Abs Are 'Core Strength'

Strong abdominal muscles are more than just pretty to look at, say these experts. Developing ab strength leads to better "core strength," meaning that many other muscle groups depend on the support and strength of the abs to do their work without suffering injury.

"You're only as strong as your weakest link," says Rice. "If you don't develop strength along a range of movement in the abdominals, then you aren't really functionally developing the muscle. You may end up with one developed area in the muscle next to many weak areas, and that can lead to injury or strain."

Exercise machines and even "ab rollers" -- curved bars that can help focus the muscle groups used in traditional ab exercises -- can help more than EMS devices. But ab rollers are real exercise, not just stimulation.

"Ab rollers present a difficult challenge and may not be appropriate for beginners with weak abdominals," says Stuhr. "If an individual doesn't have the ability to stabilize their core as their arms stretch forward, there is significant risk of shoulder or back injury. These devices may be a part of a more advanced program."

So, how can you get a flatter, more toned abdomen? Here's Robyn Stuhr's recipe:

• Reduce overall calories and fat intake.
• Get regular cardiovascular and strength exercise, under your doctor's supervision, gradually increasing exercise calorie expenditure from 150 to 400 kcal/day..
• Perform ab exercises with a trainer for a while to make sure you're using the right muscles.
• During a partial sit-up or abdominal crunch, feel yourself pulling in your stomach. Imagine your belly button pulling in toward your spine.
• Work your lower abdominals, which contribute to core stability, by learning to maintain a neutral spine during a variety of leg and arm exercises.

So in the end, as usual, there is no magic belt to melt away flab and make muscles bigger and stronger.

It's an old story, says Trentylon, who trains people at gyms in Manhattan, but nothing can replace the time and effort you put into real exercise.

"If electric impulses could replace exercise," she says, "I wouldn't have any clients."