The Rise of Electrical Muscle Stimulation Workouts: Benefits, Risks, and the Evidence

Electrical muscle stimulation (EMS) workouts employ a full-body suit embedded with electrodes that deliver timed electrical impulses, causing involuntary muscle contractions. A typical session begins with a treadmill warm-up to raise skin temperature, then proceeds with about 20 minutes of low-impact movements—such as squats, medicine-ball throws, and TRX suspension exercises—while the suit remains active. Participants commonly report delayed-onset muscle soreness lasting one to two days.

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EMS was first adopted in physical-therapy settings for post-operative recovery and was employed by Soviet athletes in the 1970s to boost strength. Physical therapists still use it to reactivate muscles after injury, surgery, or neurological events such as stroke.

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Emily Ferrara, a 43-year-old from Atlanta, switched from barre classes to EMS after online research and now attends three 20-minute classes weekly, noting a drop in body-fat percentage and increased muscle mass. Nick D’Amico, a 70-year-old double-lung-transplant survivor, began EMS a few months ago and reports an eight-pound loss and visible gains in arm, leg, and chest musculature. Dr. Greg Holtzman, division director of clinical practice for Washington University Physical Therapy, cautions that EMS primarily recruits larger fibers, can cause prolonged soreness, and should complement—not replace—functional strength training, especially for individuals with infections, cancer, or pacemakers. Crystal Busbee, a physical therapist at Emory Healthcare, describes EMS as a staple in early rehabilitation, using it to “wake up” quadriceps after ACL reconstruction and to assist stroke patients in contracting otherwise inaccessible muscles.

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Playlist, the parent company of ClassPass, reported a 16 % rise in venues offering EMS workouts between 2023 and 2025. A 2022 meta-analysis comparing EMS with conventional strength training found no overall difference in strength gains, concluding that EMS yields similar but not greater improvements.

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Ferrara and D’Amico claim rapid, noticeable improvements in body composition, while peer-reviewed research shows parity with traditional training. The literature lacks long-term safety data for healthy adults using EMS primarily for fitness, leaving a gap between clinical evidence and consumer experience.

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• “It came up on Google, and I read about the science behind it and then shared it with my old trainer, and she’s like, ‘this sounds legit.’ So I did some research, and I was like, that’s pretty interesting, only 20 minutes,” — Emily Ferrara, fitness client

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• “Once they apply the technology to your suit, you feel like you’re lifting 10 times more than you are,” — Nick D’Amico, post-transplant patient

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• “E-stim itself is probably not going to be the thing that contracts the muscle so hard that we get an injury, but because of the way it recruits different muscle fibers, people do have to be cautious of the fatigue they feel, continue to maintain good form, even in the presence of e-stim, so they don’t cause an injury just with the movement themselves,” — Dr. Greg Holtzman, Washington University PT

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• “The electro-stimulation is jumping on motor nerves and helping contract those muscle fibers, which then kind of wakes up the quad, which is super helpful to kind of engage it, and then once you take it off, the quad is firing a little bit better.” — Crystal Busbee, Emory Healthcare

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EMS offers a time-efficient workout option, but its benefits appear comparable to conventional strength training. Expanded studio offerings and growing consumer interest underscore the need for longitudinal studies to clarify safety and optimal integration with traditional exercise.

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