If you watch television in the wee hours of the night or morning, you have probably come across the infomercials for electronic muscle stimulators like The Flex Belt or the Slendertone.
So just what are these fitness devices that combine technology with exercise?
Electronic muscle stimulators (EMS) are actually much older than you might think. The concept was developed back in the eighteenth century as a way to stimulate changes in the muscle for therapuetic medical reasons. EMS devices work by training the muscle fibers via electrical impulses that evoke the contraction and release response in the muscle.
The Flex Belt, one of the most popular electronic muscle stimulators, is a non-professional wearable EMS device that uses a patented muscle stimulation technology, similar to what is used by physical therapists as a way to exercise muscles when their patient is unable to do so.
The Flex Belt generates deep contractions within central abdominal muscles and external obliques, which are intended to strengthen, tone and firm the core simply by wearing the gel-padded belt. The product, like other similar EMS devices, promises to take the place of an abdominal workout. You can wear the Flex Belt anytime whether you’re walking, watching television, or checking email.
While the FDA rejects the idea that electronic muscle stimulators can enhance the aesthetics of muscle tone, much of the fitness industry is abuzz about these devices as a way to promise consumers a way to achieve the abs of their dreams without doing a single crunch.
According to an FDA report released in 2024, while an EMS device may be able to temporarily strengthen, tone or firm a muscle, no EMS devices have been cleared at this time for weight loss, girth reduction, or for obtaining “rock hard” abs. And the regulatory agency has received complaints of shocks, burns, bruising, skin irritation, and pain associated with the use of some of these devices. There have even been a few recent reports of interference with implanted devices such as pacemakers and defibrillators.
This is not to say that electronic muscles stimulators are unsafe. The FDA simply cautions any curious, firm-ab-seeker to only use an FDA-approved EMS device. The Slendertone and Flex Belt are two such approved products.