THE THING ABOUT building muscle, cutting fat and otherwise getting in shape is, well, you have to work out. No fair, right? But what if someone – or something – else could do a lot of the work for you? Such is the commonly perceived promise of electrical muscle stimulation training, aka EMS, a type of technology that activates your muscles from the outside while you activate them from the inside.
“It’s an efficient workout,” says Jackie Wilson, a lawyer-turned-personal trainer who founded NOVA Fitness Innovation, a network of boutique fitness studios in New York City that offers one-on-one EMS training sessions.
While the specifics vary depending on the model of equipment itself and the type of supervision you’re under, in Wilson’s studios, the training involves wearing a wetsuit-like outfit embedded with 20 electrodes that sit atop major muscle groups like the pecs, biceps and quads. As clients go through a body weight or lightly weighted workout – say, a circuit including squats, pushups and jumping jacks – he or another trained staff member uses a wireless device to send impulses of varying intensities to those muscles that are contracting.
Those impulses, which feel like intense vibrations that are neither comfortable nor painful, cue the muscles to involuntarily “micro-contract” up to 40 times per second, which is 20 times more frequent than most people can willingly contract their muscles, Wilson explains. As a result, you can work your muscles far harder than you could sans technology in one-third of the time, burn 700 calories on average in about 30 minutes and reduce the need for heavy weights that can strain your joints and lead to injury, says Wilson, who launched his first EMS studio after learning that European athletes had been using the technology for years.
[See: 5 Ways to Make Any Bodyweight Exercise Crazy Challenging.]
Today, studios offering the technology either in one-on-one sessions or in small groups are sprouting up in cities across the country from New York City to Nashville, Santa Monica, California and Boulder, Colorado. Models, elite athletes and celebrities the likes of Heidi Klum and Usain Bolt credit it for helping them achieve athletic feats and body composition goals. Is it too good to be true?
From Rehab to Studio
EMS itself is nothing new. “The technology has been around for a while – mostly used in rehab hospitals and professional athletes,” says Dr. Jason Dapore, an osteopathic sports medicine physician in Columbus, Ohio.
For rehab purposes, the technology makes sense: It can activate and help maintain muscles that would otherwise atrophy after a surgery or injury. For example, Dapore explains, “the quad muscle after knee surgery can go dormant,” and that’s a problem because it’s needed for knee extension and to fend off post-operation stiffness. It makes sense, too, that professional athletes might use the technology, which isn’t cheap and hasn’t generally been accessible to the average Joe, in an attempt to gain a competitive edge, Dapore says.
But now as EMS becomes more available – and promoted – to the average Joe, its benefits are less clear. After all, the research showing its strengthening benefits are in weak or injured populations, not those who are already fit, Dapore points out. “If you take an unfit or weak body; it’s going to respond to anything you throw at it,” he says.
Fit folks looking for serious muscle gains may be disappointed in part because the technology skirts the central nervous system – a necessary muscle-building component, Dapore says. “If you’re looking to get shredded and really have awesome body composition by summer, this probably won’t get you there,” says Dapore, noting that no research has shown it can grow significant muscle. “Just because a machine is contracting your muscle at 100 percent doesn’t mean you’re getting stronger than if you were doing a good solid back squat.”