Frequently Asked Questions
How to Get the Most Out of Your EMS Unit

How does EMS work? | How is this like a TENS unit?

I don't have an injury - why should I buy an EMS unit?
Does the use of electric muscle stimulation replace stretching?
On which muscle groups can I use EMS?

Which EMS unit is right for me? | Does conductivity gel make a difference?
How long do pads last?

Pad Life & Maintenance | Uneven Twitching | Correcting Muscle Imbalances

This article is offered to answer the most frequently asked questions we receive about electric muscle stimulation (EMS). If you don't see your question answered here, please don't hesitate to give us a call at 877.698.5835 or send us an email.

How does EMS work?

Electric Stimulation units are about the size of a hand-held Game Boy and has four leads, each split into positive (+) and negative (–) connectors. Reusable adhesive pads are placed at strategic points on the muscles you want to engage in a particular workout. Connect the leads to the wire coming from the pad and you are ready for your EMS work out.

Each pre-programmed workout is defined for the upper or lower body. To begin your EMS workout, select upper or lower body and off you go. Kick back on the couch and run the program of your choice. You can also use EMS while sitting at your desk.

Electrostimulation uses electrical impulses acting on motoneurons and nerve terminals to promote muscle contraction in a manner similar to voluntary contraction. Electrostimulation can be used in two different ways: Muscular stimulation (for the development of force),and Nerve terminal stimulation (for treatments to alleviate pain).

Types of muscle
There are three types of muscle: striated (or voluntary) muscles, cardiac muscle, and smooth (or involuntary) muscle. Voluntary muscles include skeletal muscles, which allow the skeleton to move, and cutaneous muscles, which generate facial expressions for example. Cardiac muscle and smooth muscle are not voluntarily controlled.

The majority of human muscle is striated, or voluntary. There are approximately 200 different muscles on each side of the body (for a total of 400). Skeletal muscles are the target of electrical muscle stimulation (EMS).

Mechanism of muscular contraction
Skeletal muscles function through the mechanism of contraction. Muscular contractions cause the relative movement of bones around joints, and thus result in movements of the skeleton.

Muscles contract in the following way: when a person decides to make a movement, there is a change of the electric potential in the motor center of the brain and an electric impulse is transmitted to the muscle that has to move. The electrical signal is transmitted as a change of potential (voltage), an electrical impulse that traverses the motor nerve to the muscle to be stimulated. After receiving the impulse, calcium ions are freed from neural stores, which in turn causes two components of muscular fibers, actin and myosin, to approach each other. This results in a shortening of certain areas of the fiber, the so-called Z bands, leading to muscular contraction.

The energy needed for contraction is supplied by sugars and fats stored in the body. In other words, electrical stimulation is not a direct energy resource but it works as a trigger of this energy, which results in a muscular contraction. The same type of mechanism is activated when muscular contraction is produced by an electro-muscular stimulator (EMS). EMS assumes the same role as a natural impulse transmitted by the nervous system. At the end of contraction muscles relax and return to their original state.

Which EMS unit is right for me?

The difference between units is primarily in the programs each one runs. Each available program has an important place in one's training routine.

Program Allocation

Compex Fitness Unit	Globus Fitness Unit	Compex Sport Unit	Globus Sport Unit
Endurance	Endurance	Potentiation	Maximum Strength
Resistance	Preparation	Endurance	Resistance Strength
Active Recovery	Basic Training	Resistance	Explosive Strength
	Jogging	Strength	Reactivity
	Active Recovery	Explosive Strength	Endurance
		Active Recovery	Active Recovery
			Preparation
			Sprint Preparation
			Endurance Preparation
			Basic Training

All units feature the Active Recovery program. All athletes will benefit greatly from using the Active Recovery program on a regular basis. Other considerations to take into account:

Muscle Recovery. If the primary purpose of your EMS unit purchase is to achieve a deeper level of muscle recovery and muscle relaxation than you could realistically achieve by scheduling recovery and rest days into your training plan, either the Compex or Globus Fitness units will suit your needs perfectly.

Workout Replacement During the Season. The Fitness unit is also the ideal unit for you if you are planning to use the training programs (endurance and resistance) to replace the occasional missed workout and to complement and enhance completed workouts.

Training Dollars and Sense. If you are planning to use your EMS unit during the season to complement your sport-specific training, the Fitness unit is the best use of your dollar.

Taking Agility and Power to The Next Level. If you participate in agility and power sports such as baseball, football, tennis, basketball or skiing, the Sport Unit is the ideal unit for you. Agility sports are characterized by their explosive strength or power component, so you'll want to use the Strength and Explosive Strength programs, in addition to the Resistance program, to help you reach your next performance level. Other sports that have an explosive strength component (or power component) are track running, track cycling, some mountain bike disciplines and volleyball.

Off-season Peak Performance. You're also a candidate for the Sport Unit if you plan to use electric muscle stimulation extensively in the off-season for training for any endurance or agility sport.

Best in Class. If you know yourself to be someone who appreciates the functionality and programming of top-line product, the Globus Sport unit is calling your name.

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Does conductivity gel make a difference?

Conductivity gel creates a good contact area for EMS pads to transmit the electrical signal through the skin to the muscles below. It also provides a protective barrier to the pads so that the adhesive is not affected as much by oils and dirt on the skin.

Use conductivity gel for each EMS session. Put 1/4 t blobs on each small pad, and two blobs on each large pad. Spread with your finger tips. If doing two muscle groups (i.e. hams and glutes) in a session for the hams, then move the pads to the glutes without adding more. Add a bit to the skin on the glutes for additional comfort and pad life.

How is this like a TENS unit?

TENS stands for (Transcutaneous Electrical Nerve Stimulation). TENS units are predominately used for nerve related pain conditions (acute and chronic conditions). TENS works by sending stimulating pulses through the surface of the skin and along the nerve strands that fire or activate the muscles. The stimulating pulses help prevent pain signals from reaching the brain. They also help stimulate your body to produce higher levels of its own natural painkillers, called "Endorphins". TENS units run at a low, consistent frequency to achieve the pain relief results.

EMS stands for (Electrical Muscle Stimulation) which is predominately used to prevent, or reduce, muscle atrophy. Atrophy is the weakening and loss of muscle tone, which is usually experienced after surgeries or injuries. EMS has been proven to be an effective means of preventing muscle atrophy. EMS also helps by increasing blood flow to muscles, increasing range of motion, increasing muscle strength, as well as enhancing muscle endurance. EMS has pain management attributes in helping muscle related pain, such as a spastic muscle, sore muscles, or tight muscles. EMS units (such as Compex) run programs at varying frequencies to achieve the results based on the nature/intent of the program. As with TENS units, it works by sending stimulating pulses through the surface of the skin and along the nerve strands that fire or activate the muscles.

I don't have an injury - why should I buy an EMS unit?

Injury usually occurs in non-contact sports through a gradual weakening or overuse of a muscle. One reason to buy an EMS unit is to prevent this from happening. Use Active Recovery programs to speed and further recovery before the next training session or race, you can actually reduce your potential for injury.

You can also use electric muscle stimulation training programs to correct muscle imbalances with less stress on joints, tendons and/or ligaments which may have impaired function. Because the EMS unit works as the result of static versus dynamic movements, there is less use of a connective tissue.

Does the use of electric muscle stimulation (EMS) replace stretching?

No. It is important to remember that while both electric muscle stimulation and stretching may be employed to relax and warm muscles, stretching involves the extra element of tendons and ligaments and EMS does not.

Using an EMS unit regularly will enhance muscle flexibility, which may in turn complement stretching.

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How long do the pads last?

Replacing the pads after fifteen uses is recommended. However, we have found that depending on how they are used and stored, pads may not last for fifteen applications or they may last much longer.

The easiest way to tell if your pads are worn out is if you begin to notice a sharp “pins and needles” prickling sensation on the surface of the skin just under the pads. The sensation is caused by the stimulating electrical signal spreading out across the skin rather than being transferred into the muscle. Not only does this feel uncomfortable, but indicates a reduction in the effectiveness of the process.

If you feel "pins and needles", replace the offending pad(s). Also, if the pads don't stick, it's time to break out a replacement set. We recommend replacing pads one full set at a time; usually when one goes, the rest are not too far behind.

On which muscle groups can I use electronic muscle stimulation?

The pad placement booklet distributed with units in the United States shows a handful of the muscle groups to which one can apply EMS electrodes and gain the maximum benefit of the programs.

There is virtually no limit to the muscle groups that can be connected, however, you should not use an EMS unit on your head, neck or chest. Follow the warnings and cautions that are included in the User Manual for your EMS unit.

Download pictures of possible pad placements:
Common electrode placing (pdf)
Expanded electrode_placing (pdf)

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Pad Life & Maintenance

Replacing the pads after fifteen uses is recommended. However, we have found that depending on how they are used and stored, pads may not last for fifteen applications or they may last much longer.

The easiest way to tell if your pads are worn out is if you begin to notice a sharp “pins and needles” prickling sensation on the surface of the skin just under the pads. The sensation is caused by the stimulating electrical signal spreading out across the skin rather than being transferred into the muscle. Not only does this feel uncomfortable, but indicates a reduction in the effectiveness of the process.

If you feel "pins and needles", replace the offending pad(s). Also, if the pads don't stick, it's time to break out a replacement set. Replace pads a set at a time; usually when one goes, the rest are not too far behind.

Here are a few tips for extending pad life as long as possible:

1. Apply to shaved legs or body parts if possible.

2. Wash the areas where pads are to be applied with soap and water or rubbing alcohol. If you use rubbing alcohol, use a quality lotion like Lubriderm or Eucerin Cream or you will have very dry patches of skin where you used the rubbing alcohol. If you shower immediately after a workout, then do the Active Recovery routine immediately after you shower, that is ideal.

3. Make sure that the pads are kept in their plastic bags with the zip loc seal tightly closed. To make extra sure they don’t dry out, you should store all of your open bags of pads in a larger zip loc bag if you live in a dry climate.

4. We have found that the use of conductivity gel not only helps reduce the prickling sensation, but extends pad life substantially. Use just a small dab on each 2"x2" pad and two small dabs on each 2"x4" pad. Spread evenly in a thin layer with your finger. If you have extra on your finger, then spread on the plastic piece that the pads stick to, and this will keep your pads moist in storage. The gel is absorbed by the skin, and doesn't reduce the "stickiness" of the pads. If you overdo it with the gel, and pads won't stay positioned, just remove the extra gel and you're back in business.

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Uneven Twitching

About 50-75% of electric muscle stimulation users will experience uneven twitching during their EMS workouts. What we are talking about is when one muscle group twitches or contracts more noticeably than its counterpart even though both are set to the same level of current.

For example, let’s say you are doing an active recovery routine and you have all four channels (two on each quad) set to the same number of 20 milliamps. However, you notice that your right quadriceps muscle is twitching or shaking quite vigorously while your left is only twitching slightly.

The reason for this dissimilar reaction to the same amount of current provides visual and numeric proof that you have a dominant and weaker muscle. The weaker muscle is the one that isn’t twitching as much. This is due to the fact that a lower percentage of the muscle fibers are responding to the input from the motor nerve being the electronically activated. Increasing the current on that weaker muscle group will “wake up” those un-recruited muscle fibers. So, you may end up running 1-5 mA on the two channels connected to your weaker muscle.

Don’t really worry about the numbers, just make sure you are getting the same twitch out of both muscle groups. This holds true for all muscle groups you work with the EMS unit. Adjust the current level for each muscle independently to achieve the same level of twitching or contractions on both sides of your body.

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Correcting Muscle Imbalances

Not only will an EMS unit identify muscle imbalances for you, but electric muscle stimulation also offers the most effective way to correct the problem that we have ever seen. Until now, the only way for athletes to correct a muscle strength imbalance was by doing single limb exercises which are difficult to perform correctly and are associated with a higher risk of injury.

Uneven muscle strength (aka muscle imbalances) are immediately apparent when you use EMS. If you notice one muscle twitching less than the other when the intensities are equal, you have a strength imbalance. Simply increase the intensity on the low twitching side until both muscles are twitching equally. It is recommended that you increase the "less twitching" muscle side by no more than 5mA over the other muscle. This is especially effective with the Strength programs. You will be able to gradually reduce the difference. Once you have each side twitching equally at the same intensity, you will have corrected the imbalance.  

The changes that occur in muscle physiology in response to conventional and EMS training is an increase in nervous innervation to the fibers. This first response to training occurs relatively quickly, about 2 weeks. Increasing nerve fiber number allows for stronger and more fiber innervation and contraction. The next response is an increase in contractile machinery - the results that you can physically see when someone gains muscle mass. As the muscle responds to the increased loads, there is a concurrent increase in muscle fiber size, not actual muscle fiber number. Along with an increase in contractile machinery there is an increase in the enzymes related to the metabolic processes that are being stressed.

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