Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In


Mobility & Recovery


The benefits and applications of electrical muscle stimulation for CrossFitters.


If you’ve been following the CrossFit Games in the last few years, you may have noticed many of the competitors slapping electrodes on their bodies between heats, then lying back and watching their muscles twitch and quiver beneath a tangle of wires. What gives?

Electrical muscle stimulation — or e-stim — technology has been around for ages, but only of late has it been applied in a nonmedical setting. The basic premise of an e-stim machine is simple: An electrical current is passed through strategically placed electrodes into a muscle in order to elicit an involuntary contraction. But that’s where the simplicity ends. These millennial machines go way beyond the pain-masking effect of the standard TENS machines found in every physical therapy office across the globe. Different wavelengths, wave strengths and machine settings create a variety of scenarios that could completely change the way you train, grow and recover.


The most obvious benefit of e-stim and the one most grinders will appreciate is that it benefits recovery. Recovering more quickly means reduced muscle soreness, decreased incidence of injury, higher training volume and greater training frequency. Translation: More WODS, better bods.

“These days, everyone is trying to push themselves more and is training harder than ever, but they are only recovering partway,” says Ryan Heaney, CEO of Marc Pro. “What they need is a more sophisticated system of recovery. E-stim fills that need.”

According to Heaney, e-stim dilates blood vessels, causing a flushing action that brings in fresh blood and nourishment without causing fatigue. It also helps power lymphatic drainage. Cells kick their metabolic waste into the lymphatic system of vessels, which, unlike the circulatory system, is passive — i.e., there is no heart pumping it through your body. In order to move the waste, the vessels need to be physically compressed through muscular contraction. Enter e-stim. “Applying e-stim takes advantage of that physiology, contracting the muscles, compressing the lymphatic vessels and accelerating waste removal,” Heaney says. “That is pure recovery.”

As soon as you can after working out, stick the electrodes on the muscles that need the most recovery for a flushing session, because over time, the congestion of waste thickens, Heaney says. Remember: The faster you recover, the sooner you can get back into the box and the harder you can train.

Muscle-Fiber Optimization

Another interesting application for new-gen e-stim is the selective recruitment of specific types of muscle fibers. Depending on the frequency setting, you can target fast-twitch, super-fast-twitch or slow-twitch fibers exclusively.

“If you’re going to run a marathon, you’ll warm up differently and use different muscle fibers than if you’re trying to PR on your 1RM squat,” says Eric Glader, senior director of business development at Compex/ DJO Global. “Marathoners want to hit the slow-twitch endurance fibers, and squatters want to activate those fast-twitch explosive fibers. Using e-stim can help facilitate that engagement, no matter what the activity.”

Applying the device to muscles before workouts causes them to fire, waking them up, preparing them to work and optimizing your subsequent training session. “Most injuries come from the misfiring or lack of firing of the muscles,” Glader says. “For instance, ACL injuries are caused when the quad does not contract properly. The machine fires signals into the muscle so the muscle has no choice but to contract. It’s like putting an alarm clock next to your bed and turning the sound up really high.” This alarm maximizes the muscle fibers impacted by your training, meaning you build more muscle, strength and explosiveness in less time, according to Glader.

So get to the box early and check out the WOD. Decide which fibers need waking up, then select the program on your device that targets those fibers. Zap away for anywhere from three to 20 minutes, depending on the program/fiber, then hit it.

Increased Strength and Conditioning

Most gains don’t happen in the box but during the hours and days afterward, so after workouts is an ideal time for wiring up — but not for the reason you might think. “Heavy weights create discomfort, which in turn make your body create more muscle fibers, forcing strength adaptations,” Glader says. “You can mimic this activity with an e-stim device. The machine indiscriminately forces that adaptation, activating more muscle fibers than your brain could on its own.”

For instance, let’s say you want stronger legs. After a heavy leg workout, you’d wire up and apply e-stim to those same muscles, targeting the same fibers you just used and forcing further adaption to increase strength. Think of it as a finishing set, only without the physical effort.

Another interesting benefit is that of conditioning. “Our research has shown that when used regularly, five days a week for an hour a day, e-stim can cause the creation of new blood vessels in the targeted region,” Heaney says. “It’s a conditioning effect. For instance, if I am not a runner and I start running, after a period, my body responds by saying, I need more capacity, and creates new blood vessels in the legs. Same thing with e-stim: It will proactively improve vascularity and conditioning in that area without extra physical work.”

Improving your vascular system means more blood vessels, faster delivery of oxygenated blood, and greater endurance and performance. Your muscles will have a greater capacity for work and greater potential for growth as a result.

Heaney advises focusing on a weak link in your chain — shoulders, lower back, knees, ankles — and using the machine to build up that weakness from the inside out, improving capacity and ability.

So could e-stim make you a shoo-in for the 2016 Reebok CrossFit Games? Maybe … maybe not. But it could help push you past your own sticking points and help you hit your own PRs to rule the roost at your own box.

“We don’t believe the machine alone does the work,” Glader adds. “It’s a supplement to good biomechanics, and you have to put the work in to get the results.”

Some E-Stim Guidelines

Purchase a product appropriate for you. If you’re not an elite athlete, don’t buy the top-of-the-line all-inclusive product right away. Start with a simpler and less-expensive model and move up from there.

Review your physiology lessons. Effectiveness of e-stim depends on proper electrode placement. Go online for the best ways to apply the electrodes.

Use your product wisely. Follow the time recommendations and safety guidelines associated with your product and the programs you’re using at all times. It’s still electricity, people — don’t mess around with it.

Make sure the setting or program you’re using is correct for your training protocol. You don’t want to use a harsh, intense contraction before doing a workout because it will cause fatigue of the muscle. And if you’re doing an explosive workout, don’t charge up your Type-1 endurance muscle fibers beforehand.

Decide how you want to use the protocol. If you’re looking to improve performance, for example, check out models that include programs such as the fiber-specific workouts (Compex). If you want to emphasize recovery, purchase a model that focuses on that aspect (Marc Pro).