Author: Giovanni Ciriani
You must have heard that Electrical Muscle Stimulation is used for rehabilitation. But after hearing about it for sport training, most people get a good laugh, as this reminds them of the marketing hype “exercise while doing nothing and watching TV”. There is a reason for this bad reputation, because done incorrectly and with the wrong tools, EMS will not achieve any result for you. Therefore I’d like to explain what EMS can really do for you.
What EMS does
First the basics. Voluntary muscle contractions are controlled by the brain, which sends electrical impulses through the nerves that innervate a particular muscle. EMS mimics these electrical impulses, and acting on the same nerves that innervate a muscle, cause it to contract involuntarily. It is important to understand that EMS doesn’t cause the muscle to contract, but it triggers its contraction. The energy for the contraction still comes from the same biochemical processes that make our body work. Therefore an EMS contraction is “physiologically natural”. Because our muscles are composed of different types of fibers (think of slow twitch and fast twitch fibers), EMS electrical impulses can trigger different types of contraction. By harnessing these differences EMS machines can help fine tune muscles for specific goals: development of force; development of endurance; help recover from strenuous training faster than pure rest; avoid next-day muscle soreness.
EMS is not simple and has to be done correctly. That is partly the reason why there are many skeptics . Utilizing the correct stimulation parameters is part of the answer (there are half a dozen parameters to be set correctly). For instance if one utilizes a TENS device (those typically prescribed for low back pain), the stimulation will not be adequate for a training effect on a desired muscle. Or, if one borrows an expensive clinical device, the parameters will be difficult to set and will not address a specific training goal. Thanks to advances in technology, in the last 10 years, portable and relatively low-cost stimulators have appeared on the market, already programmed for different athletic goals, putting results within reach of the sport community. In Europe they are used by a growing number of coaches and athletes. In the US the number of sport users is a much smaller niche. Since one still needs to know what to do, and have enough experience to use EMS programs consistently with the sport goal, I recommend to talk to a coach that has EMS background.
How it works
I mentioned that our muscles are composed of different slow twitch fibers and fast twitch fibers. In a voluntary contraction of slow-twitch fibers our nerves send electrical impulses, typically 10 to 20 times per second. In the case of fast-twitch fibers, our nerves send electrical impulses, typically between 40 to 80 times per second. EMS can mimic these and other nervous patterns precisely, helping to tweak muscle work toward slow twitch or fast twitch work. There are studies that have shown that EMS has the capability to modify the proportion of fast vs slow-twitch muscle fibers.
Several studies on individual- and team-sport athletes (eg, swimming, track and field, weight lifting, basketball, volleyball, ice hockey, rugby) have reported significant improvement in maximal strength, and in some cases even in anaerobic-power production (vertical jump and sprint ability) likely to affect field performance. These improvements, like any type of training, follow specific routines: the EMS programs used during a session, involve a number of repetitions (10-40); the contractions are strong and long enough, and adequate rest time between one contraction and the next to allow the muscle to recharge; the EMS training is repeated several times a week; results are obtained after several weeks. This is complicated enough, but fortunately in the current generation of EMS machines, the EMS programs needed for a session are ready and properly labeled. However, the frequency of EMS training per week and the number of weeks of training are best decided with a coach who has EMS experience. In addition performance improvement of sport movements requiring neuromuscular coordination can only be obtained if EMS is used in conjunction with “voluntary traditional exercise”.
One form of EMS though, is very successful for almost everybody, without the need of a coach. Active recovery is an EMS program that generates rhythmic muscle twitches, in fast succession, promoting blood flow. It feels like a massage, but because of the incessant and rapid nature of the twitch, it is several times more effective, and helps remove the byproducts of exercise: the breakdown of proteins and other residues that typically cause inflammation and next-day soreness. Very recent sport-medicine studies have shown that EMS Active Recovery programs are more effective than other forms of recovery. Because EMS Active Recovery generates only twitches, it doesn’t cause secondary training effects, and it can be easily and safely done without knowing anything about EMS. Even performing EMS several times a day does not interfere with other forms of voluntary training, although the closer to the training, the more effective it will be.
One obvious advantage of using EMS Active Recovery is that it facilitates access to the muscle by naturally-produced biochemicals, which our body employs to rebuild stronger muscles. As a consequence, athletes who are striving to rapidly improve their performance will be able to recover faster and possibly squeeze one more training during the week. The other advantage is that by decreasing next-day muscle soreness, the athlete will be able to avoid skipping days.