Do EMS Workouts Really Work? What Experts Say About Electric Muscle Stimulation

Electric muscle stimulation workouts — in which a suit fitted with electrodes sends electrical impulses through the body to trigger involuntary muscle contractions — are growing in popularity across the United States. But do they actually work? Experts offer a nuanced verdict: useful in specific contexts, but not necessarily superior to conventional exercise for most people.

What EMS Workouts Involve

EMS stands for electrical muscle stimulation. During a session, a machine sends electrical impulses through electrodes embedded in a wearable suit, causing muscles to contract without the wearer initiating the movement voluntarily. Workouts typically last around 20 minutes and involve minimal movement — short sets of squats, light weight lifting, or resistance band exercises — while the electrical current amplifies the muscular effort.

The technology has deep roots in physical therapy and rehabilitation, and gained a foothold in Soviet sports science in the 1970s as a tool for building muscle strength in athletes. Today it has migrated into mainstream fitness studios, with the number of ClassPass-listed venues offering EMS sessions rising more than 16% between 2023 and 2025, according to ClassPass parent company Playlist.

High-profile athletes have embraced it: soccer star Cristiano Ronaldo has described using EMS as a supplement to his training, and actor Tom Holland used EMS equipment to prepare for a Spider-Man film.

What the Science Says

The research on EMS workout electric muscle stimulation effectiveness is mixed. A 2022 meta-analysis comparing EMS against conventional strength training found no meaningful overall difference between the two methods in terms of strength development. “NMES training shows similar but not greater strength gains than conventional strength training,” the study concluded.

Dr. Greg Holtzman, division director of clinical practice for Washington University Physical Therapy, said EMS has legitimate applications at the extremes — for post-surgical patients rebuilding atrophied muscles, or elite athletes targeting very specific muscle groups for precise gains. But for the average person seeking general fitness, he views it as less efficient than functional strength training or weightlifting.

“As a general exercise tool, probably not as efficient as it could be — or comfortable, to be quite frank,” Holtzman said. He noted that EMS recruits large muscle fibers first and simultaneously, which differs from how the body normally works — conserving energy by activating smaller fibers before larger ones. This unnatural recruitment pattern can lead to prolonged soreness, though Holtzman said the electrical stimulation itself is unlikely to cause muscle injury. The greater risk, he said, is that fatigue from the stimulation could cause form to break down, leading to injury from the movement itself.

People with active infections, malignant forms of cancer, or pacemakers should consult a physician before trying EMS, he added, and skin irritation is a common mild side effect.

Where EMS Genuinely Shines: Rehabilitation

Crystal Busbee, a physical therapist at Emory Healthcare, described EMS as a “staple” in clinical rehabilitation. She uses it routinely after ACL reconstruction surgeries, placing electrodes on the quadricep muscle to retrain the brain to contract it following a period of post-surgical dormancy.

“The electro-stimulation is jumping on motor nerves and helping contract those muscle fibers, which then kind of wakes up the quad,” Busbee said. “We use it typically to kind of wake us back up and minimize the amount of muscle that we may lose in post-surgery or post-injury.” EMS can also assist neurological patients — such as stroke survivors — to contract muscles they can no longer activate voluntarily.

In a general fitness context, however, Busbee echoed Holtzman’s reservations. “If people can tolerate exercise appropriately, they should be able to get strength gains without using a tool like EMS,” she said, noting that while EMS activates and recruits muscle fibers effectively, it may not directly translate to true strength gains in the way conventional resistance training does.

What Users Are Experiencing

Anecdotal results from regular EMS users have been more enthusiastic. Emily Ferrara, 43, has been attending EMS classes at an Atlanta studio three times a week for two years, and says her body composition has measurably shifted toward more muscle and less fat.

“I can get the results. I’m so sore for like a day or two after, and I think it’s like the most efficient process,” Ferrara said. She added that the 20-minute format is a key draw for someone managing work and family commitments. Ferrara also does cardio twice a week and underwent body composition testing to verify her results.

Nick D’Amico, 70, began EMS a few months ago after recovering from a double lung transplant four years earlier. He said he has lost about 8 pounds over two and a half months and seen visible improvements in muscle mass in his arms, legs, and chest.

“Once they apply the technology to your suit, you feel like you’re lifting 10 times more than you are,” he said. “You literally can get quite a workout in less than 30 minutes.”

EMS workouts appear most beneficial for people recovering from surgery or injury, and for athletes targeting very specific muscle groups. For general fitness, the science suggests results comparable to — but not significantly better than — conventional strength training. For those drawn to the time efficiency of a 20-minute session or who struggle to engage muscles through standard exercise, EMS may offer a useful complement to a broader fitness routine — ideally under medical guidance.