The suit is a lot like a spring-weather wetsuit that stops at the knees and the elbows. Like with a wetsuit, putting it on can require some effort. Twenty electrodes cover the abs, pecs, glutes, thighs, pecs, biceps, and multiple parts of the back. These are dry electrodes, so you don’t have to wet Pepper’s suit down before you put it on (a common requirement for older gear), but your sweat will improve the conduction of electricity. Of course, if you’re pregnant or need a pacemaker, you shouldn’t use an EMS suit.

Pepper’s suit, available in sizes from XXXS to XXXL, is designed to be very tight so that the electrodes won’t slip into places you don’t want them. Since the suit is intended to be worn with nothing underneath it, that’s a particularly important consideration. And based on the way certain body parts are situated beneath the fabric, it is definitively not something I felt I could wear in public without a cover-up layer.

The only removable part of the suit is a small box that connects at your hip. This is the brains of the operation and its power source. Charge it with a USB-C cable and it’s good for at least 10 training sessions.

Pepper’s app divides workouts into three categories: strength, cardio, and relax, each with a different electrode firing pattern. (Oddly, I discovered that a few workouts were available only in German.) I tried workouts across all of the categories but spent nearly all of my time in strength, as my goal was to build muscle. Strength sessions all involve electricity pulsing through the suit for four seconds, then pausing for four seconds, then repeating for up to 24 minutes.

ScreenshotPhotograph: Christopher Null

The workouts—there are dozens, I rarely repeated any—are tuned to the pulses so that you’re activating muscles across your body while the pulse is on, then usually resting while it’s off. Again, Pepper’s approach is that EMS only works if you are using your muscles while they are being energized, so many of the workouts involve entire body flexes, stretches, and crunches, four seconds at a time.

Plugging In

I’ve experienced isolated EMS for a back injury once before, so I had an inkling of what Pepper might feel like, but the full-body experience is on another level entirely. Fortunately, Pepper eases you in, starting off with soft pulses you can’t even feel. Each of Pepper’s 10 workout zones can be individually controlled, with the power level ranging from 1 to 100. My first video-based trainer said she starts to feel the pulses at level 25, so I slowly ratcheted my way up, bit by bit, until I had all regions hitting around 20.

The shocks on the lower settings don’t really hurt, but you can definitely feel them; powerful, rapid vibrations that shake your insides and sometimes burn a little on the skin. No pain, no gain, right? As I continued to push the levels up, I discovered there was a fine line—really 1 or 2 points on Pepper’s 100-point scale—between tolerable and painful. Those vibrations turned into racy shocks that could be almost paralytic at times, and I spent the rest of my initial 12-minute session dialing the power level back down.