People training using EMS. Miha Bodytec

Electrical Muscle Stimulation Takes the Work Out of Your Workouts

So why is the FDA concerned?

By the end of 2021, Matthew Patten, 60, a political and communications director for a London think tank, bet he had gained “a stone” (about 14 pounds) due to his extensive, quarantine-induced sitting-and-binging-at-home. But, as the world opened up again, so did the ski slopes. In March 2022, he had arranged to go on a ski trip with friends, but he started to have serious concerns about his physical conditioning ahead of hitting his beloved slopes.  

“I hadn’t skied in two years,” Patten says. “I was concerned about my lack of muscle strength and feared injuring myself on the slopes. I also felt unhealthy.”   

Hitting the gym was out of the question. “Walking into a gym full of people doing weights and running has always made me very self-conscious,” Patten says. Nevertheless, a resident of central London, he one day wandered into Vive Fitness, a local place offering electrical muscle stimulation (EMS) training, who connected him with for this story.

EMS is the practice of delivering small currents of electricity to muscles that are under strain and working out. After literally spraying the trainee with water (a great conductor of electricity) and having them wear a suit with built-in electrodes targeting and stimulating specific muscles during the workout, the trainer controls individual intensities in the main muscle groups: quads, calves, glutes, lower back, lats, upper back, abs, pecs, biceps, and triceps. Just a 20-minute workout of high intensity and lots of incoming tiny currents are enough to replace a normal 90-minute workout of sweating your fat off in the gym, EMS advocates say.

Too good to be true?

After 10 weeks of training, Patten reports he went from about 247 pounds to underneath 220 pounds (he is 6 feet 3 inches tall). He went on his skiing trip where he says he skied “further and longer and in a more dynamic way” than ever before. He has since continued training via EMS, to which he credits his ability to ride his bike around London easier. It also makes mowing the grass in his garden more effortless, he says. “I’m getting a lot out of EMS in a shorter time,” he says. “And sort of intellectually, I feel stronger in myself,” he continues. “As you get older, working out is harder and puts stresses and strains on your back and joints.”

Muscles and aging

The benefit of EMS for people in older demographics has been the focus of intense research over the last few years. EMS has been found to have positive effects on muscle mass, strength, and power as well as on total and abdominal fat accumulation in people over 70. It has been shown in small clinical trials to help both men and women over 70 build muscle mass as a way of addressing sarcopenic obesity, an emerging geriatric condition characterized by both loss of muscle (sarcopenia) and obesity. It can assist elderly females keep osteopenia, or low bone mineral density, at bay. A metanalysis of 13 randomized controlled trials that was published in the Journal of Bodywork and Movement Therapies in March 2022 found that EMS for people over 60 significantly increased not only their muscle mass and strength, but also their usual gait speed (the same study found that EMS-training did not help decrease waist circumference and triglycerides, though). 

“A lot has to do with telomeres,” says Ruben Tabares, a strength and conditioning coach and nutritionist. Tabares has been using EMS on his clients, some of them elite athletes like the fastest British woman in recorded history Dina Asher-Smith, since 2010. Telomeres are structures consisting of DNA sequences and proteins located at the end of our chromosomes. Telomere length has long been considered one of the best biomarkers of aging (as we age, telomere lengths shorten, leading to senescence, cellular death, or tumors). Research published in Experimental Gerontology in April 2021 compared master athletes (veterans of 16 years or more of high-level competition) to age-matched non-athletes. It found the former have longer telomeres, suggesting that strength training was one of the parameters for keeping telomeres strong.  

“Seeing as EMS training does increase your strength, then you could point to an increase in cellular life,” says Tabares. “I have read the scientific research on EMS, and it does increase strength, more so on people who have never trained (seriously) before. You’re doing something where you’re stimulating the muscles but not in a way that they can get injured,” he continues.

“The wasting away of muscle due to zero gravity is one of the most challenging current issues with space travel.”

Of the 100 scientific projects the four astronauts of the mission Cosmic Kiss have been working aboard the International Space Station since October 2021, one is called EasyMotion. This one uses EMS to enhance astronaut training throughout the space mission and to cut down on the overall time spent on exercises below the current 2.5- hours-a-day minimum. NASA aims to offset the muscle atrophy astronauts who spend long periods in outer space may endure through EMS.

“The wasting away of muscle due to zero gravity is one of the most challenging current issues with space travel in general and that is why NASA was involved in the use of EMS,” explains Tom Holland, an exercise physiologist and human performance expert. However, astronauts still have to exercise several hours a day using specialized equipment to prevent sarcopenia, he is quick to add. “EMS has not yet proven to be a valid replacement to traditional strength training, and may even have deleterious effects,” says Holland. 

One of them might be rhabdomyolysis.

Why the FDA cautions on EMS

Rhabdomyolysis is a serious syndrome where damaged skeletal muscle breaks down rapidly, filling the bloodstream with tissue waste products and sometimes leading to kidney failure. It’s seen in people who sustain severe injuries in car crashes, people who are repeatedly beaten and tortured, and in victims of snake venom poisoning and flesh-eating bacterial infections. But there have been incidents of serious athletes training with EMS who were harmed by it. For instance, EMS training caused two young male professional soccer players to suffer from rhabdomyolysis and abnormally elevated activity of creatine kinase—an enzyme located in the heart, brain, and skeletal muscle—increased amounts of which are released into the blood after muscle damage.

In addition, the U.S. Food and Drug Administration (FDA), which regulates EMS devices sold in the United States and keeps a record of illegal unregulated EMS devices, reports some of them have caused shocks, pain, skin irritations, bruising, and more. The FDA has banned any EMS device that does not meet its strict pre-market approval. Some scientists advise individuals interested in taking up EMS to first consult a physician, and they have called on doctors to screen for risk factors for rhabdomyolysis before starting. They also recommend regulating the education of operators and people who work in gyms offering EMS. 

In any case, the global EMS market is expecting moderate growth between 2022 and 2030, with Miha Bodytec, XBody, StimaWELL EMS, and Visionbody being some of the leading global EMS equipment manufacturers. Being reviewed on a case-by-case basis, there are currently 205 FDA-certified EMS devices that can be legally sold without a medical prescription in the United States. Two years ago, Miha Bodytec, a German market leader in design and manufacturing EMS equipment, achieved FDA-clearance for their devices and established a U.S. headquarters in the Chicago metropolitan area. Soon thereafter, the company’s CEO Jürgen Decker announced that his firm would begin assembling machines in the United States with German-made parts. Interestingly, the North American EMS market is currently lagging behind the European and Asian markets, where EMS is steadily on the rise. In Germany, over 12 percent of all fitness facilities are devoted to EMS, and that number is expected to grow, partly due to high rates of cancer and arthritis in the population (and the subsequent need for rehabilitation) as well as the increasing popularity and visibility of EMS-related fitness.

“Our waiting lists are getting huge.”

The experts interviewed for this article tell that it’s safe to assume EMS is a good training option when traditional resistance training cannot be performed, such as in rehabilitative settings, assuming a properly regulated device and professional guidance. And it could enhance the fitness regime of both the lay person and the top athlete, suggests Holland. But a lot more research is needed to determine the extent to which EMS can fully replace gym-based strength training, he adds—and that seems to be the general consensus within his community. That opinion hasn’t deterred this futuristic, high-speed approach to working out from gaining a loyal following. 

Celebrities like Madonna, Heidi Klum, and Elizabeth Hurley have used EMS to keep fit, while mega-athletes like Usain Bolt, Rafael Nadal, Christiano Ronaldo, and Dina Asher-Smith have already endorsed it. “In London alone, there are about 50 studios at a capacity of 120 people,” says Phil Horton, country director for Miha Bodytec in the United Kingdom. “Our waiting lists are getting huge,” Horton continues.

And at least one EMS user interviewed by swears by it. “I exercise for 20 minutes per week and the electricity is allowing for some serious muscular exercise. To get the same out of a conventional way of strength training, everything would have to be much more physical and exerting, and I don’t want to be a powerlifter anyway,” Patten says from London. “It’s an interesting way of thinking about fitness, one involving technology, [which is] a big part of our lives elsewhere.”

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