Does Electrical Muscle Stimulation Really Improve Your Workouts?
I’ve tried a lot of weird workouts in the name of science, but nothing quite like seeing myself in an EMT suit for the first time. It’s all black, with belts and buckles everywhere. A long wire is about to connect me to the computer. I feel like I’m ready to fly a spaceship or a giant robot. Instead, I’m going to do lunges and push-ups, and they tell me I’m getting a much better workout than those suckers who just go to the regular gym.
To try it out for myself, I accepted an offer for a free class at BODY20, a growing chain of EMS fitness studios. His workouts are expensive, ranging from $40 to $100 per session, depending on where the studio is located and what membership you sign up for.
So, is EMS training better than regular training? Probably no. (We’ll get into the details in a minute.) But after seeing myself in the mirror, I kind of understood the appeal.
What is EMC?
Electrical Muscle Stimulation (EMS) workouts are popular—not for the first time, and probably won’t be the last—thanks to their futuristic vibe and the fitness industry’s constant push to bring you a newer, cooler workout than what everyone else is doing.
Electrical muscle stimulation is a family of techniques and technologies that cause muscles to contract by passing a weak electrical current through the body. You may be familiar with some other methods of passing electrical current through the body for health and fitness purposes, so I will describe them for comparison.
If you’ve used a TENS machine for pain relief, you know one type. You’ll attach sticky electrodes to your skin and turn on a handheld device connected to them by wires. TENS uses a low current that produces a tingling sensation but does not cause muscle twitching or contraction. The idea is that the tingling sensation interferes with the transmission of pain signals. TENS stands for transcutaneous electrical nerve stimulation. This means that an electrical current passes through the skin and sensations are picked up by the nerves, but it is not intended to cause muscle contraction.
On the other hand, if you used e-stim at a physical therapist appointment, it is more similar to what happens in EMS training. When I was rehabbing from knee surgery, quadriceps recovery was a top priority. So, I would do leg presses and leg extensions, and at the end of the session, the physical therapist would sit me in a chair and attach sticky electrodes to my thigh. He slowly turned the handle and my quadriceps began to contract. When we reached a level that was slightly painful but tolerable, he would leave the machine at that level and we would let him work on my quads for what I remember was about 10 minutes or so.
EMS training is closer to an electrical stimulator, but the sensations from it are completely different. When you perform EMS training, you are strapped into a full-body suit that delivers current to multiple muscle groups at the same time. The current isn’t as strong as in my physical training sessions, but you also won’t just be sitting in a chair—you’ll be doing workouts while the electrodes force your muscles to contract harder than exercise alone.
What happens in EMS training?
I showed up for my EMS training at a boutique fitness studio in the suburbs, next to a veterinary clinic and within sight of a yoga studio. I had to sign a waiver that included a disclaimer advising me not to participate if I had a pacemaker, metal implants such as plates or rods, or if I had epilepsy or cancer, or was pregnant. The list also included items that mentioned dehydration, history of rhabdominal disease , “strenuous exercise” in the past 72 hours, or other EMS training in the previous five days.
The studio manager told me about this and explained that on the first day I would only be able to do a fairly short workout without weights. Over the course of a few sessions, people are introduced to longer, harder workouts, although you never train for more than 20 minutes per session.
The area behind the table was divided into two main rooms. There was a small fitness room with mirrors and a black floor where workouts were conducted. Behind him was a room with an InBody scanner and several brightly lit locker-like cells, each containing an XBody suit .
(I played along and got an InBody scan, even though I know it’s not very accurate at determining body composition. It gave me flattering numbers, so I can’t be too mad.)
I was given a set of clothes to change into: a black, fitted shirt with three-quarter length sleeves and matching cropped trousers.
I’ve read that some EMS studios recommend not wearing underwear; In this studio, it looks like you’re going to leave yours. I agree. For planning purposes, the clothes you wear under your suit will get wet. Finally, you may want to take a change of dry clothes with you.
While I was putting on the provided workout clothes, a Body20 staff member sprayed water on the inside of the first aid suit I would be wearing. Instead of having electrodes attached to the body as with a TENS machine, these electrodes are built into a suit. They each have an absorbent pad and that’s what she soaked. Water provides a conductor between the electrode and the skin. This means you’ll end up with wet spots on your biceps, stomach, quads, butt, and so on.
There are no electrodes on the calves and forearms, which did not surprise me; they are not a priority muscle to train for most people. What really surprised me was that the deltoids (the most visible muscles of the shoulder) are also not covered with electrodes. This must be to allow the shoulders to move, but it seemed like an odd omission since many people want to exercise this area for either appearance or functional reasons.
The training itself was quite simple and short. The suit turns on and you perform a set of exercises, such as lunges or squats. Then it turns off and you have a short break – just a few seconds – before starting again.
Body20 offers strength and cardio classes. Strength classes seem to be the main event and the rules don’t allow you to do them too often. Cardio workouts are performed with less current running through the suit, and you move from exercise to exercise, much like those bodyweight circuit training videos you may have done on YouTube. Those workouts that you are allowed to do more often.
The Body20 staff kept referring to the FDA’s rules regarding frequency and intensity, but when I asked about it in a follow-up email, I was told that the rules actually came from XBody, the manufacturer of the suits. The FDA regulates EMS devices and requires them to be cleaned before use. They say they have received reports of bumps, burns and other problems with the devices being sold illegally without clearing customs. Overall, these manufacturer guidelines seem reasonable to me; I would be wary of purchasing any emergency equipment unless you can verify that it is FDA approved.
How does EMS training feel?
As with my experience using e-stim during physical therapy, at the beginning of a Body20 session the trainer would increase the intensity of the current and ask me to stop it when it seemed strong but tolerable. Too high and it may cause pain or cramping; too low and you may not feel anything at all. (The electronic stimulus in PT was much stronger than we had planned for this session.)
During the exercises, I could definitely feel the current increasing my muscle contractions. One or two times while doing a triceps movement, I felt like my triceps were kind of stuck. It didn’t hurt, but it felt like my arm wanted to stay straight, almost like a slight cramp in the triceps.
There were dumbbells in the room, but we didn’t use them during the introductory training. Instead, the trainer had me hold balls in my hands (like stress balls) and move them as if I were doing dumbbell curls or doing triceps kickbacks. The current actually made them feel like I was doing something .
However, it wasn’t a hard workout. I kept hearing that I should expect pain after this. Instead, I left the studio and headed straight to my weightlifting room to do my usual Monday workout (cleans, power snatches, power cleans, foam rows). I felt a little more tired than I did when I showed up to practice fresh, but it felt more like “just did a thorough warm-up” than “did another workout first.” The next day I didn’t have any pain.
For someone who doesn’t throw weights every day, it’s reasonable to expect some soreness. An easier, shorter workout for your first workout makes sense if you don’t know how your body will react. But in my experience, it’s really not that different from regular strength training. If anything, it feels less like a muscle stimulus than a strong day at the gym. You just don’t do that much.
Is EMS training effective?
When it comes to exercise, I’m very enthusiastic about it: if you enjoy it, or if there’s something about your chosen form of exercise that makes you want to do it and keep coming back, then I support you, whether it’s Pilates or powerlifting. or something in between. I’m sure there are people who are interested in doing lunges in an EMS suit, but who wouldn’t do lunges at home for free. If an EMS studio membership is what you’re used to (and you have money to spend), knock yourself out.
But there’s something we need to talk about: the fact that each of these studios claims that EMS training is either better than regular training or that it produces the same results in a fraction of the time. For example, Bodstreet says you “only need to exercise 20 minutes a week.” Tummo says: “One 20-minute session is equal to 3-4 days in the gym.” We202 claims that a 20-minute session is “equal to 3 hours of traditional training.” Fitopia claims its 20-minute workouts are “equivalent to 90 minutes of regular workouts.” Body20 , where I went, is no exception, saying its classes can “achieve results in just 20 minutes that would take hours in a traditional gym.”
So, of course, I asked about it. The PR person who introduced me to Body20 sent me a list of studies and specifically pointed to this 2016 study that compared full-body EMS to high-intensity resistance exercise . It concluded that EMS training “can be considered a time-efficient but [expensive] alternative to [high-intensity] resistance exercise for individuals seeking to improve overall strength and body composition.”
I dug around, wanting to crunch the numbers. As promised, the study included EMS training similar to those offered by Body20 and other studios. And it was found that both the EMS and non-EMS groups had similar increases in muscle mass and strength.
But the claim that you need hours in the gym to equal one EMS workout? This study was in no way confirmed. The training sessions without EMS lasted 30 minutes . (Or, to be more specific, 30.3 minutes, give or take 2.3 minutes.) Even if the rest of the study is completely true, credible, and applicable to you personally, you’re only saving ten minutes per workout, not hours.
And I have doubts about the applicability of the study, even beyond the timing issue. The study involved 48 healthy men between the ages of 30 and 50, and all of them were “untrained,” so the results should be taken with a grain of salt. Almost everything works for people who don’t exercise. If you already go to a gym or fitness studio and are thinking about making the switch to EMS training, I honestly wouldn’t expect much from EMS. This might be just as good. Could be worse. We have no evidence that it would be better.
All in all, I think the only reason to do EMS training is if you think it’s a fun way to spend your money. (We all have our passions and stupid hobbies; maybe this is yours.) It’s no smarter or better way to exercise than going to the gym or taking up an athletic hobby like running or rock climbing.