The Science Behind EMS

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While the concept of EMS has been around for thousands of years – dating as far back as 500 BC. – it has gained a considerable amount of attention within the fitness industry over the last few decades.

With promises of increased strength, fat loss, faster results,  and improved muscle recovery, it isn’t hard to understand why.

But what exactly is EMS and can science back these wonderful claims?

What is EMS?

EMS stands for Electric Muscle Stimulation, and, as the name suggests, it involves using electric impulses to force a contraction in the muscle.

“Why on earth would a person willfully subject oneself to shock treatments” you may ask?

Well, let’s consult a cult classic novel by Mary Shelly.

“It Lives!”

Picture Dr Frankenstein in his laboratory one stormy evening with his creature connected to a series of circuits. Finally, we have a conductor above the ominous mansion to attract the lightning from said storm.

Once the lightning strikes the conductor, the electricity travels through the circuits, jolting life into his creation. The human body isn’t that much different. 

You see, the brain sends electrical impulses through the central nervous system and to the desired muscles. Once these impulses reach their target, the muscles are “brought to life” and contract – a voluntary contraction to be precise.

However, when using an EMS device, we can save time and stimulate our motor neurons directly, resulting in an involuntary contraction.

While both of these methods seem to have the same result, the physiological differences in the two become quite significant in the realm of fitness.

What is the difference, and why does it matter? 

Well, to conserve energy, our bodies recruit motor units according to their threshold and firing rate during a voluntary contraction. When executing a movement, the body chooses to activate slow-twitch type I muscle fibers first, which we use for lower intensity and high endurance movements.

As more force is required, fast-twitch type II muscle fibers are activated, which are used for quick and explosive movements. This is known as the ‘size principle’.

The advantage of EMS is that it reverses the order of recruitment. EMS allows for better access to the larger neuron of the fast-twitch type II muscle fiber, which can now activate immediately. While on paper, this might not seem like much; in reality, it has very significant benefits.

Muscle Fibre TypeWhat it’s Used For
Slow-Twitch (Type 1)
Endurance activities like cycling, swimming and walking. They contract slowly and take longer to get tired.
Fast-Twitch (Type 2)Quick and powerful movements such as sprinting or jumping. They get tired quickly and consume a lot of energy.

Faster, Stronger, and Safer

When we recruit our muscles frequently, our body starts adapting by finding the quickest nerve pathways to shorten communication time.

The use of EMS can potentially accelerate this process with frequent contractions while sparing your joints and tendons the added weight.

Secondly, instead of individual recruitment of fibers, EMS allows all the fibers to fire at once. In comparison to a maximal voluntary contraction, an EMS contraction is 30% greater.

In a nutshell then, the more muscle fibers that fire and the quicker they activate, the more weight you can lift. 

Real-World Results

A study published in the Journal of Strength and Conditioning investigated the effects of electromyostimulation on a group of elite rugby players over a 12-week period.

The study included 25 players in total, with 15 undergoing EMS training and 10 serving as a control group. Players received 3 sessions per week for the first 6 weeks, leading to a total of 18 sessions. During the second half of the study, sessions were scaled down to 1 per week. All sessions were done at the same time of the day and on the same days of the week.

After 12 weeks of training, players showed significant torque improvements under maximal eccentric and maximal concentric conditions, as well as improvements in squat strength, squat jumps, and drop jumps. This proved that even already well-conditioned athletes can gain a performance edge over the competition with the help of regular EMS therapy.

Using The Science Behind EMS To Train More Effectively
Njoku brothers training with their AWI Powersuit

While this is great news for those who seek to become stronger, not everyone exercises for this reason. This brings us to the additional benefits.

Weight Loss

A 2014 South Korean study titled Effects of high-frequency current therapy on abdominal obesity in young women: a randomized controlled trial examined the effects of EMS on young obese women over a 6 week period.

22 women participated, with 10 undergoing therapy and 12 serving as a control group. Like the first 6 weeks of the study on rugby players, the experimental group received 3 therapy sessions a week for 6 weeks, totaling at 18 sessions by the end of the study.

Compared to the control group, the experimental group showed a reduction in waist circumference, body mass index, subcutaneous fat mass, and total body fat percentage without even modifying their regular diet or exercise routines.

The conclusion by researchers was that “the use of the high-frequency current therapy may be beneficial for reducing the levels of abdominal obesity in young women”. 

Note that the key lies in the high frequency. But why?

Higher Frequencies and Fat Loss

High-frequency treatment causes heating of the targeted area. This is due to repeated oscillation and friction of the molecular structures. Localized heat in these subcutaneous tissues could potentially help with lipolysis (the breaking down of fat), and thus the removal of cellulite or fine fat particles, which would result in a reduction in waist and thigh circumference. 

Even faster results are possible when combined with a low carb meal plan. The beauty of EMS is that the frequencies can be adjusted according to different goals one has, and that brings us to the final claim.

EMS and Muscle Recovery

To facilitate quicker muscle recovery, we need good blood circulation, and that is why you often see athletes massaging their muscles during sporting events – to force blood through the muscle. Proper blood flow means metabolic waste products can be pushed out of the muscle, and vital nutrients can be let in to help you recover. 

Apart from massaging, we can also facilitate this process with a combination of contrast showers and stretches, or low-intensity exercise on a rest day – known as active recovery. EMS basically replicates this active recovery. 

Read: Why Should Athletes Use EMS for Recovery

However, unlike the high-frequency currents used for fat loss, here muscle recovery is assisted with the use of low-frequency stimulation. The result is short and low-intensity muscle contractions which help lower blood lactate levels within the muscles. 

Final Thoughts

Have we found the “holy grail” ?

The fat loss and strength gains speak for themselves. Not only are you able to improve your fitness level, but you can now do so in just 20 minutes a day, 3 days a week using the AWI Powersuit. Less time and lower impact makes it the perfect solution for those with joint injuries or a tight schedule. 

However, like any fitness tool, it needs to be used in combination with good nutrition and fitness habits for optimal results. 

Does this mean that the days of pumping iron are over? Most certainly not. Instead we have opened a gateway to explore a multitude of possibilities for combining traditional and modern fitness techniques.