Electrical Muscle Stimulation and Speed

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By Carl Valle

What’s it Worth?

For decades the use of Electrical Muscle Stimulation, or EMS for short, was a highly touted option for elite athletes to reach higher levels of performance. For years many athletes have used EMS as a recovery option, especially after a muscle tear. Recently the trend of EMS use is back again, with the Marc Pro, Globus Speed Coach, and Complex Units growing in popularity with power athletes. Many questions are resurfacing, the most obvious, does EMS work for recovery and performance? A better question is the measurable value of EMS and improvement, be it regeneration or a training stimulus. If one is going to look at any athletic endeavor, the improvement in speed of an athlete is a good characteristic to investigate. For years several experts have been proponents of EMS and some gurus speak about special protocols and various proposed mechanisms, none of them researched of course, and several concepts are actually counterproductive. This article will answer the tough and invasive questions on EMS and put to rest some of the hype regarding electrotherapy. Several myths and some studies will be showcased to explain what does and does not happen when you shoot current through the body. Many athletes envision becoming a superhero by harnessing powers after a slight shock to their legs and arms. The truth is that EMS is extremely limited to recovery and the effects on performance are minuscule for some athletes. To find out if something is worth doing, one has to find out how much something is worth. In summary, EMS will be judged by a simple metric; how much does it help athletes get faster?

EMS for Recovery Myth

I was disappointed when I read the slides of a few self-proclaimed experts in recovery and regeneration share some rather unprofessional and borderline information. Not only has the information presented been proven to be bogus in the research, logical holes existed in the theoretical concepts. This is the problem with EMS. Proponents are making the process complicated in order to promote their “expertise” and focus attention on alluring charts and fictional protocols. The truth is that research, logical reasoning, and historical data are a nice spread of evidence that demands a unanimous verdict. EMS is a poor option for recovery, and the application is limited in the real world.

A universal problem with coaches looking at science of rehabilitation is that recovery is not the same as sub-maximal injury. Fatigue and remodeling of an injury is hardly synonymous with using a modality to help with heavy training or competition. Similar to the bodybuilders swearing by a specific protein powder blend because of a 1982 study on burn victims, expecting 340% hypertrophy after training. A person is receiving intravenous amino acids after a third-degree burn, much different than the studies of what sport scientists are seeing after workouts with healthy athletes. We see the same mistake time after time when a rat model demonstrates a 30% increase in capillary density compared to a sedentary rodent. It is promising, but hardly strong enough proof that a highly trained athlete is going to get a real world improvement from using EMS. Marginal gains is important when athletes are chasing the 1%, but some theoretical gains are a thousand times smaller than 1%, and time and energy should be applied on the most effective and efficient options. Here are the claims gurus are speaking publicly about recovery.

Edema — Showing before and after photos of swelling is a popular marketing approach to seduce the athletic population. A swollen knee circumference being reduced in days hints to possible improvement, but other options exist. One of the most effective ways to rehabilitate an recover an athlete is aquatic exercise. Countless studies support its use, but the lymphatic system works both passively (through movement) and with the circuit like response of the nervous system that is active. Humans are designed to use foot strike and the contractions up the kinetic chain to help with wellness and natural lymph flow. The Marc Pro is touted to be an alternative and convenient option to reduce swelling, but two muscles is very inefficient. Even if you go with other models that offer more pads, the process is not like a foot strike that incorporates dozens of muscles each strike. A pool, deep or shallow, can be adjusted for pain free contractions that are on paper better options. Yes, it is convenient to lay on a table passively at times while playing Angry Birds on a smartphone or tweeting Instagram photos of random night clubs, but active usually trumps passive with lymph flow.

Blood Flow — I made the mistake years ago about thinking that circulatory adaptations or healing are accelerated with tempo running or conditioning circuits. True, a few response physiologically does occur, but just having blood run through the body faster doesn’t mean a muscle will regenerate faster or more completely. Also higher blood flow from passive EMS does not include more special healing factors at the cellular level. The time course of repair requires days, and the amount that EMS provides is so small, other therapeutic options that are pain free deliver more blood flow. Light exercise has an array of great athlete wellness benefits, but passive EMS is getting only a fraction of the benefits. Athletes who are healthy enough to do light exercise should do light exercise, not be lazy and expect EMS to provide the same reward. Again, a post-surgical rehabilitation approach may find success compared to nothing with EMS, but recovery and rehabilitation are not always overlapping to all users.

Muscle Tone — I have used Elastography, Tensiomyography, Electromyography, Myotonometry, and a few other systems to evaluate tissue status. EMS is so weak in improving the muscle status that we could not see anything with jump tests and no statistical difference in speed with sprint evaluation. Improvement of muscle tone from exercise (adjusting) is far more influential than EMS. Muscle tone at rest is more of a sign of proper training than anything else, but after hard workouts EMS does have a benefit compared to nothing. Light stretching and again aquatic exercise can serve as an effective replacement, and changes of tissue tone are fleeting. Anyone having an awesome massage and jumping on a crowded plane in the “economy seating” section will see all those benefits disappear. While you can keep reapplying EMS as it is a convenient delivery system, muscle tone without rest and good training will never make slow runner fast. Finally, prolonged contractions with slow wave EMS has shown to target slow twitch fiber, and biopsies demonstrate negative adaptations when used for prolonged periods.

Fatigue — EMS will not help with recovery of substrate or the Central Nervous System. The Peripheral Nervous System may benefit slightly with a change in muscle tone that removes a slightly ischemic muscle. Good tone or more reactive and ready fiber is great for meets that need a sympathetic state, but resting tone should contrast meets by being relaxed and in a great parasympathetic state. A good resting state will allow the circuits of the lymphatic system to work, and a better healing environment. Even with all of the efforts to create a better resting environment, don’t expect workouts to see noticeable changes that are measurable. Perhaps over the course of a month all of the marginal gains do add up, but like sleep, the exact measurable changes are difficult to see. In the future, we may start seeing more controlled studies on fatigue and rejuvenation, but we barely understand fatigue now so it will be hard to see what to expect until one does more performance tests and EMS applications.

Pain — A tricky subject in discussion is the concept of pain and the athlete. Neuroscience demonstrating that pain is linked to the brain is not helpful, when athletes are creating tissue disruptions and tendon microtrauma. Pain chronically with some low-back patient in their 60s is nice for internet arguments, but medical imaging, biochemical assessments, and subjective indicators are far better than Venn diagrams and flow charts. Pain may not be a real sign of injury or damage, but it is worth listening to, and one should look at pain as a possible early warning system. Having a false positive is always better than having a functional deficit later, confirmed with severe structural damage. One can function with some degeneration or structural abnormality, but using a neuroscience only approach when dealing with biomaterial, is like only hiring software engineers that need to produce a smartphone….don’t forget the hardware. Discomfort of EMS is at higher settings, and some studies show slow waveforms may help create an analgesic response, explaining with electroaccupuncture may have benefit and why dry needling has a poor validity history. If pain is a problem, sometimes light exercise and other therapeutic options like thermotherapy can create a placebo response with actual biochemical (temporary) changes to manage training soreness, but healing is still time dependent.

The key takeaway from all of the above is the point of recovery is to create change that elicits higher levels of performance later. Recovery applications are to accelerate the functional status of the body, meaning you either increase capacity by doing more because of the frequency of training or higher levels of near supramaximal output by more complete recovery. Recovery is not about applying complementary therapies and nutritional methods, but the result of training, rest, and supportive modalities that show measurable impact to performance. The difference between assisted training with recovery and passive options must be measurable, or one is just dealing with a placebo at best. Placebos are valuable additions to confidence and dealing with heavy training as a Spa experience may just be the tipping point to feeling better mentally, but eventually it must deal with the physical side of consciousness. If EMS were helping with recovery so much, we would see performances similar to the levels of dopers. At the end of the day, the history is a great PH test to see if one sees a sizable pattern and commonality of why. Research and real world results and outcomes are a great combination. EMS is just a tiny percentage of help, and those focusing on EMS for recovery need to watch the video from ASPETAR for a wake-up call. Professor Nicola Maffiutetti breaks down the conjectures and explains why we should rethink EMS for recovery purposes.

Many coaches and therapists will find the above video disheartening and want to argue their experiences with EMS for recovery. It is important to note that without a mechanism and good controlled studies, a few elite athlete testimonials could be just drug assisted factors using gadgets or gimmicks to explain their inhuman performances. Users of EMS should think about conveniences of EMS but not to exclude active exercise, as smart training trumps the hype of gurus.

EMS for Performance Hype

Now that recovery is outlined performance changes of EMS need to be evaluated logically. One of most annoying areas I see is ornamental use of training to promote expertise. I have been guilty of creating programs based on artistic design, and learned the hard way that consistent outcomes are better than aesthetically pleasing workouts on paper. Ironically I see that good training will result in natural and elegant design, leading to higher performances. The reason I point this out, is that like myself, coaches are enamored by great presentations that promise results coming from such minutia, that even people who promote marginal gains are disbelievers.

Recently a PowerPoint presentation was sent to me regarding performance and EMS, and it had some great points and was well prepared. Unfortunately, the protocols and expectations were questionable. One example is the common periodization scheme of using EMS with training in order to reach the benefits. Here are three tough questions one must ask every time they wish to put on an electrode on a muscle.

Question 1: In your sport, what measurable difference are you expecting in performance? For example, if one is a 100m sprinter with a focus on maximizing potential, what time benefit does it provide? Like plyometrics and sleds, does it provide improvement in the first 30m (acceleration), maximal velocity, or both? If a benefit exists how much is it worth at different periods of development? Is it a tenth for a 10.7 high school athlete or a tenth for a sub-ten athlete? Anytime I ask for the value, even ballpark estimate, I get either crickets (silence) or a preamble explanation ducking a time benefit statement.

I think a three-hundredths benefit exists in the 100m for someone who has run the A standard and uses EMS for an entire season at best. No way would one session do anything. Otherwise we would see every Super Bowl team doing EMS right before kickoff instead of using stimulants. EMS is not potentiation, so a series of sessions are required. I could be wrong, and it provides more, but my ceiling is realistic since a tenth too high and variable. The value of a tenth is also variable depending on one’s 100m time. Going from 9.6 to 9.5 is far different from an 11.2 athlete going 11.1. Also improvements are the result of many factors, so the best way would to see if an athlete who is near their peak and has plateaued is seeing a significant and consistent boost from EMS.

Question 2: If a measurable performance output is truly enhanced with EMS, what is the cost of recovery needed? EMS does not heal muscle, repair tendon, replenish glycogen, or recharges the brain. Everything has a cost, and the demand of EMS if it is truly increasing output needs to factor in the toll on the body if it is working. While EMS itself does not create damage or strain, the adaptation of combining training and use of EMS is hopefully increasing the theoretical output later, a benefit that has baggage to an athlete’s body.

Question 3: Can you or your organization properly use EMS in a way that replicates the demands of studies? When theory or even good research hits the real world, the rules change to how closely can one apply the modality to athletes. Culture and attitude will be different with various sports and teams, and the biggest gap I see is measuring the usage of modalities as most of the market is focused on measuring output and not recovery. We have force plates and heart rate monitors, but very little data coming from therapeutic modalities. Companies do a poor job of servicing coaches and teams with consumer products since elite athletes represent a small percentage of their profits and are more marketing tools than targets to profits. While it is nice that an athletic trainer can check off the modality on an iPad as they observed it first hand, several modalities are best performed at home and data is usually lost or unreliable. Mentioned earlier with the interview with Jose Fernandez, a good API will change how we see the value of recovery to staying healthy and performing with athletes. Does anyone see the challenges of testing and stimulating posterior chain muscles on other athletes?

Practical EMS Realties with Speed and Power Athletes

The best studies look at pure performance indices such as jumping or speed tests because even if an athlete is getting faster in the 30m, it may not be ideal for a 100m sprinter who is suffering from poor max velocity and speed endurance. A team sport athlete usually receives less benefit than sprinters. Even if a benefit on the field, greater athletic ability is not a hindrance and lesser abilities certainly is a prime culprit to why skilled athletes retire. Interestingly many team sports on paper will receive an unfair advantage (only to pure speed athletes) because they have less training time than Olympic athletes. Team sport athletes see the most gains because they are not focusing on maximal development but hitting sufficient benchmarks to reduce injury and repeat performances expected for entertain schedules. Remember, team sports are about the fans and are businesses first, and training has suffered because of this.

Combining EMS with strength programs is more of a dark art than a clear sport science. I believe that coaches in speed and power overly complicate applying EMS. Coaches will make assumptions that placing EMS during the key phase or “cycling” it will deliver certain gains. While color coded periodization models charted out during conferences are exciting, does anything think that going 3 weeks on versus two weeks off is much different from 2 weeks on versus one week off? What happens if one does it year round? Does anyone think doing EMS for a straight 90 days is going to be dangerous or potentially too powerful? Who thinks that doing EMS during a recovery week will ruin adaptations? Will it undo the results of the previous three weeks? What if one does it in the morning instead of after a training session? What about doing it during plyometrics and speed sessions and not during maximal strength phases? What if you do not do any maximal strength work at all? What if you barely use weights?

It is likely that following the total amount of sessions of EMS done in studies and using it for the majority of the season is a safe bet. Not to be hypocritical but the guideline just shared is my own experience by attempting to extrapolate research studies. I would rather error by doing it nearly year-round to compliment training, rather than doing it for one phase and loose potential benefits. All of this is a theory, and it is up to the team and athlete to decide what is sensible. I also like to pair EMS by doing it on intense training sessions because I like days off from any discomfort and balance training. I like the Hard / Easy approach for most circumstances and EMS done every day seems to be mentally annoying to most athletes. While utopian obsessive compulsive athletes exist, usually they are the least talented and are rare at higher levels. The Nicola Maffiutetti study with soccer players doing plyometrics and EMS benefited after four weeks, but again the subjects are not representing everyone. If a program was doing a serious weight training program and other modalities would the benefits wash out? Most likely for sprinters who devote all their resources to performance will see less of an impact, and since research shows that EMS without an actual training stimulus is not really fruitful with athletes, one should not expect a lot of gains going head to head with other “active” options. The improvements seen by the studies are likely accurate for that situation, so coaches and athletes have to be careful to adjust for differences of their own training.

Applied EMS in the Real World

Simplifying anything involved in training too much is a danger, but a good working outline of using EMS for training can distilled to basic needs and let reality ensure that what is on paper is properly executed. At the end of the day, an athlete will decide themselves if the benefit is worth the inconvenience, and I think most athletes will put in 16-48 sessions of EMS a year. It may be during late offseason to prepare for pre-season risk with team athletes, or it could be year round for a chronically 10.0 sprinter looking to go under the ten second barrier after being stuck for two years.

EMS falls into a strange category of responsibility since athletes can apply EMS on their own, but sometimes anatomical placement requires a little assistance. If athletes believe in EMS they may be compliant, but if they do not it could be a burden and a relationship breaker. Like nutrition, athletes are expected to take ownership of their bodies and what goes into them (or on them). Coaches have known for years that the hours away from the practices and competitions is where many of the athletes thrive or fail, so EMS is similar. We are almost at the point with EMS being now syncing with smartphones and the cloud that coaches can push and receive data on the sessions, but that means historically we are reliant on story, rather than concrete data. Here are four important factors to successful applications of EMS.

Total Muscle Groups — Logically propulsive muscles seem the most bang for the buck, but every muscle has value and role. Does one focus on muscles that are lagging? How does one know that without real exhaustive use of EMG, muscle readiness testing, and kinetic/kinematic data? While EMS body suits are growing in popularity, no system has 50-60 pads that can be used at the same time. Very dedicated athletes may invest into longer sessions, but after 45 minutes even playing on smartphones might get old. Priorities should be three to six muscle groups at the most.

Anatomical Pad Placement — Obviously one needs to ensure they are stimulating the muscles they want, so some education is needed by the athlete if they are doing it on their own. Even a trained therapist may not be able to hit the right area perfectly, especially in crowded areas. With the nervous system being a little murky with EMS research, how important local muscle groups are to the big picture is unknown. Regardless of the mixed outcomes of the research, accurate pad placement is a good idea, even if a global nervous system is a possible outcome.

Sequence and Programming — I think it makes sense for athletes to use EMS on the days they do speed and power, as doing so doesn’t harm results and doing it on conditioning days seems to not give a day off psychologically.

Device Settings — Amazing, some swear by devices designed for only “pulse” or electrical massage with strength improvements. Based on the research done on commercial products, slow waveforms do not create strength improvements with healthy athletes. Many studies use actual commercial products and get results favorable, showing that not only on paper EMS has value, but it can be done in the real world with affordable models that are widely available.

Most athletes need to get the sessions done for 60-90 minutes three times a week. To get the results the research shows, that means five weeks of EMS is needed to get the results demonstrated. In my experience, most athletes quit beyond 50 sessions a year. I think selling athletes in getting it done during sensible time periods is far better than expecting a “stacked” result from combining EMS with specific phases of training. Linking up 4-6 weeks of use a few times a year seems reasonable and realistic to most coaches and athletes.

Closing Arguments for EMS

In the end, results matter, and EMS seems to have good enough support to invest into a personal unit or device. Most training plans do not program a rehabilitation or injury phase, so EMS units are helpful when no other options exist, especially after surgery and early rehabilitation phases. My .03 estimate for the 100m dash may be conservative for some and generous to others, but the train of thought of quantifying EMS is a good start. As coaches and technology evolve over time, we will start to see more precise estimations of the value EMS has for speed and other athletic feats.

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