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The Compex Sport: Shock therapy for workout warriors

Already a staple for pro athletes, electric stimulation--sort of like shock therapy for triathletes--is now being marketed to the mainstream. Video: Zapped to glory

Michael Kanellos Staff Writer, CNET News.com
Michael Kanellos is editor at large at CNET News.com, where he covers hardware, research and development, start-ups and the tech industry overseas.
Michael Kanellos
4 min read
The Compex Sport inflicts intense, deep pain. That's its chief selling point.

A day after riding an exercise bike while wired to the Sport--an $899 device that electrically stimulates and revives muscle tissue that ordinarily wouldn't get activated during exercise--my legs were still sore. To put on pants, I had to crouch down and sort of hop into them, and that was after several stretches. My left bicep, which temporarily got hooked up to the Sport, felt like it would had I entered a one-armed chin-up contest.

And those were the aftereffects. Being hooked up to the machine just for a few minutes made my legs feel as if they had become trapped in a vise. In short, it was scary, but oddly compelling at the same time.

The Sport is the latest piece of athletic gear to migrate from the professional locker rooms to weekend warriors. Skier Alberto Tomba employed electronic stimulation, according to the company, on his way to three gold medals at the 1988 and 1992 Winter Olympics. It's a fixture in the training rooms for soccer teams like Juventus and Ajax too.

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Video: Zapped to glory
Michael Kanellos takes a ride with the Compex Sport.

Compex refashioned its professional device for the consumer market in Europe a few years ago and has just brought it to the States. It's aimed at hobby athletes who don't have time to train as much as they'd like, but still want to outdo their friends or competitors. Slap on the electrodes and that quick training session becomes a full-body experience.

Despite the pain, the device actually reduces the potential injuries, explained Heiko Van Vliet, a European marketing manager for Compex and a coach and trainer who works with the CSC bicycling team and the Norwegian national skating team. Because you don't have to lift large amounts of weights or run an extraordinary large number of miles to get an intense workout, the wear and tear on joints, bones, and cartilage gets reduced.

Regular use over time additionally builds up muscle tissue, which takes more pressure off joints and bones.

"With this, we are able to do in 25 seconds what you have never felt in your life," said Van Vliet. "For professional athletes, it is a must."

And seconds is all it takes. I only did three sets of exercises with my legs during a demo at San Francisco's City Cycle. I did the "resistance" setting for seven 7-second intervals. In this mode, the device sent electric charges through two electrodes every 7 seconds to my quadriceps while I pedaled an exercise bike. The jolt activated the slow-twitch muscle fibers in my thigh. A 30-second (or longer) rest period followed each 7-second jolt.

I followed this with seven 4-second intervals on the "explosive strength" mode, which targets fast-twitch muscle fibers. I then followed with 1.5 minutes on the much mellower "endurance" setting.

The day before the test, I had ridden my own bike approximately 50 miles over several hills, so I'm not that out of shape. Even so, after doing what amounted to less than 3 minutes of actual exercise on the Compex Sport, I was sweating, panting, and howling. Customers coming into the store stared, and then asked the sales attendant what was going on. (Weirdly, after a burst of electricity, you feel fine and can even hold conversations.)

Electrical stimulation essentially works by tricking the body. To get muscles to contract in an ordinary situation, the brain sends an electrical signal to the appropriate nerves, which then stimulate the muscle fiber.

As people age, however, certain neural pathways become predominant. When the brain sends a signal, the same fibers get tickled; the muscles that get ignored begin to atrophy.

"Your body is very efficient. Why should it conserve something that it isn't using?" Van Vliet explained.

An ordinary person who doesn't work out much uses around 35 percent of their muscle mass, while someone who works out somewhat frequently can boost that number to closer to 50 percent, he said. Body builders might use 80 percent to 85 percent.

To excite those dormant fibers, the Sport sends a signal directly to the nerves via electrodes attached to your leg, bypassing the brain all together. It stimulates as many fibers as possible, not just the ones the nerve customarily excites. When the current begins to flow, your muscles immediately jump into a hard mound.

"We can recruit up to 99 percent of your muscle fiber," Van Vliet said. That stimulated muscle tissue is then more receptive to signals from your brain the next time you run or bike in the real world.

The pain first-time users feel after using the Sport comes from delayed onset muscle soreness that comes from doing new activities. (Think of the pain you'd have if, out of the blue, you decided to run every stair in a football stadium.) The more you use the device and exercise those ignored muscles, the more the pain decreases. Kip Potter, who is helping import the Sport to the U.S., hooks himself up to the device three times a week. He can still walk upright.

The amount of current flowing through the device is quite low--in the 20 to 40 milliamp range--said Van Vliet. Anecdotally, it seems correct. For an article in 2004, I volunteered for a hit from a Taser, which emits much higher amperage. It knocked me flat and my hands felt numb for nearly an hour after a 1-second tase.

Even during the longer, 7-second charges inflicted in "resistance" mode on the Sport, I could still talk and move, and hadn't even come close to losing consciousness--a big difference. The level of power is also controlled by the user. (In the video, Van Vliet has it set two-thirds of the way up, relatively high for a maiden voyage.) To shut it off, you can just pull the electrodes off.

But the company recommends working out with a trainer initially.