Check out the article in Men's Health and Fitness all about the safety of NMES written by Brittany Smith. www.mensfitness.com/life/entertainment/healthy

Is This Healthy?

Athletes are using personal neuro-muscular electrical nerve stimulation to get an edge in the gym and unleash their full potential. We investigated whether it's safe and if you should try it, too.

Is This Healthy?: Neuromuscular Electrical Stimulation Devices

Short answer: Yes. With very few side effects, and potential to supercharge recovery, muscle, and strength gains, using an at-home neuro-muscular electrical nerve stimulation device can be valuable for pretty much anyone.

The practice of zapping muscles to stimulate contractions was first introduced in the early 50s among European countries, like Russia, for space programs, in order to prevent muscle atrophy in astronauts, says Drew Little, C.S.C.S., a performance specialist at Michael Johnson Performance, an elite training facility in McKinney, Texas. More literature came out on the technology in the 70s before it made its way to the U.S. and Canada in the 80s and 90s.

How It Works

When you attach a device—like what's offered from companies such as Compex, pictured above, to a muscle and begin a program (for more on the types of programs you can do—and to read our review on two Compex devices—click here), an electrical current travels through the electrodes, down your nerve fibers, sets off their motor neurons, then stimulates a strong muscle contraction, mirroring what your nervous system typically does on its own, only to a greater extent. Now, you can attach a device during a warmup to prime your body for lifts, use it during a workout to elevate bodyweight or weighted moves for better results, pop it on in lieu of a workout with a resistance setting, or use post-workout to speed up and kickstart the recovery process.

NMES devices stimulate and contract 100% of your muscle, something your body can't voluntarily do; your body caps stimulation at about 45 percent for normal guys and around 65 for weightlifters as a protective mechanism to prevent injury. So, your body prevents you from lifting something monstrously heavy, like a car, so you don't obliterate your body (though there are "freak" instances and scenarios where this is overrided and adrenaline kicks in so you can surpass this maximum).

A NMES device also hastens the amount of time it takes to trigger slow and fast twitch muscle fibers. "During a squat or bench press, depending on the load, your body will recruit slow-twitch muscle fibers first (which takes about 20 milliseconds), then roll into the fast twitch (which takes 50-60 milliseconds)," Little says. "But a NMES device bypasses that pathway, so all muscle fibers are recruited at the same time."

You stimulate hard-to-get-to muscle fibers quicker and more effectively than you can with traditional weightlifting; plus, it puts less strain on your joints. And, unlike a TENS (transcutaneous electrical nerve stimulation) unit, which delivers very small doses of electric currents to relieve pain, you can use a NMES device to accelerate your results in the gym, from warmup to cool down. Find out more about how to use it here.

Who Should Use NMES

Cyclists, runners, triathletes, lifters, baseball players, football players, basketball players, and other athletes—beginner or advanced—can use these devices to get faster, go longer, jump higher, get stronger, reduce chronic pain, enhance circulation, prevent imbalances, and strengthen the core. Basically any guy who wants a bit of an edge when it comes to health and fitness should try one out.

This doesn't mean you should quit your gym membership, though. It's best used to enhance your regimen, not replace it.

Precautions

There are few negative side effects. "There's a rare possibility electrical burns can happen with poor pads or faulty, damaged wires, or that someone uses the device incorrectly," says physical therapist Chris Kolba, Ph.D., C.S.C.S., at The Ohio State University Wexner Medical Center.

For instance, you should never apply any muscle stim device to your neck, head, or chest. Severe spasms can close your airway and make it difficult to breathe; scientists don't know the effects of stimulation on the brain; and electrical currents to the chest can throw off and disturb rhythms to your heart.

"The only other kind of complication that can come from this type of device is if people have pacemakers and cardiac conditions; you need to get permission from your medical provider to see if it elevates your risk of heart attack," Little adds. People with epilepsy, have recently had acute trauma, fracture, surgery, and some other conditions shouldn't use a device either. Speak with your healthcare provider before starting anything new.

And while there aren't particularly harmful outcomes from using NMES, there are times when the device can hinder your progress and goals. "You want to periodize your training regimen with a device, so you're not using resistance programs 52 weeks a year," Little explains. To keep your body from adapting, you need to provide new foreign stimuli. In other words, you can over-use a device like this for strength, power, and resistance (though using it daily for recovery, warmups, and cool downs is perfectly fine).

Kolba concludes: "I prefer foam rolling, soft tissue and mobility work, sleep, nutrition, and a proper strength and power program for significant gains." That said, a device could help enhance and assist all of the above. For a more in-depth profile of how to incorporate a device in your regimen, read our review on two of Compex's most high-tech devices.