Muscle Stimulation & Weight Loss

Be wary of products that promise the impossible. Many belts, wraps and other devices that electrically stimulate muscles indicate in their advertisements that they take the "work" out of working out. Because weight loss and fitness is inherently simple, but not easy, a product that shortcuts the effort should be looked at with a critical eye.

Function

Electrical muscle stimulation, or EMS, works on the principle that the brain's signals to the muscles during activity is nothing more than an electrical impulse that calls the muscle tissue into action. By sending electrical impulses directly into the muscle tissue, EMS devices cause a tightening similar to what happens during exercise. This activity is said to enhance active exercise or replace it entirely. The result, according to the manufacturers, is enhanced weight loss, increased muscle performance and a better physique.

Form

Units are generally lightweight and easy to use. Bands sized for specific areas of the body, including the mid-section, thighs, biceps and triceps, are held in place by Velcro strips. A separate control unit, attached to the band with insulated wire, delivers the impulse to the target area by means of a series of electrodes pressed against the skin by the band. Units are either battery-powered or plugged into the wall through an adapter.

Claims

Muscle toning is the touted benefit for most units, but some claim to promote weight loss by replicating the calorie burn you would get from actively exercising the stimulated muscle groups. One major brand says this is because of glycogen use by the stimulated muscles. When muscles run out of ready glycogen, they must make more from carbohydrates, fat and other nutrients.

Efficacy

EMS is a proven treatment for rehabbing muscle injuries in sports medicine facilities and rehab centers around the world, according to the American Council on Exercise in a study of the issue. However, oxygen consumption, a key indicator of increased muscle activity and energy use, remained unchanged in test subjects who wore the devices at rest, according to a study published in the Journal of Conditioning Research" in February 2005. This suggests that calorie burn remains largely unchanged when the device is worn while working at a desk, watching TV or just relaxing, contrary to device manufacturer claims.

Legal Issues

EMS devices are useful as prescription treatments for muscle injury, muscle spasms and prevention of atrophy. Claims of reduced girth, body contouring, weight loss or bust development represent a misbranding of these products, according to the U.S. Food and Drug Administration. In an alert dated Oct. 2, 2009, the FDA authorized customs officials to refuse entry for devices branded with these and other misleading claims.