Electrical stimulation machines have been around since the 1950s, however over recent years, muscle stimulators have become more readily available – and increasingly popular, especially within the CrossFit community.
PowerDot’s Duo (above) is an incredibly popular EMS unit – and for good reason.
The muscle stimulator works seamlessly with your smartphone to give you that edge with your exercise preparation and recovery, strength, resistance, and endurance training.
What exactly is a TENS unit?
A TENS unit is a machine most commonly used for pain relief, and recommended by many professional bodies including the NHS.
The machine connects to a set of electrodes that you place on key points on your body. A small electrical current is then passed through the electrodes.
This current helps to block the pain signals from reaching your brain to offer relief and relax the muscles.
Can a TENS unit help to build muscle?
Not really. A TENS unit is not designed to work your muscles. What you’d need is an electric muscle stimulator (EMS).
TENS and EMS devices look very similar, almost identical, however there are some big differences between TENS and EMS.
The devices may look practically the same and utilize electrode pads and mild electrical impulses, however their goals are much different.
Though it is worth noting there has been some research to show that TENS does have benefits for muscles.
Market leading TENS brand iReliev’s latest device, iRenew is a combination unit that offers the best of both worlds, it boasts impressive TENS and EMS capabilities:
With a combination device like iRenew you’ve got all the bases covered so you’ll never be left wondering whether you should have opted for a TENS or EMS unit!
How does Electric Muscle Stimulation (EMS) work?
EMS essentially works by stimulating motor nerves and inducing muscle contractions, mimicking the way your muscles contract during a workout.
The devices have programs designed for both exercise preparation and recovery, along with programs for strength, resistance, and endurance.
In this short video you can see exactly how Michael Cummings uses PowerDot’s Smart Muscle Stimulator to help increase upper body strength:
What’s the difference between TENS and EMS?
To understand the differences between TENS and EMS you need to comprehend how they work with nerves and muscles.
A TENS unit stimulates the nerves and blocks the pain signals from reaching the brain.
EMS causes the muscles to contract by mimicking the action potential that comes from the central nervous system, it is these contractions that make the unit more effective for muscle building.
Compex’s Wireless 2.0 Muscle Stimulator is a top-of-the-line machine with 10 programs in total, nine for EMS and one for TENS:
FDA regulation of Electric Muscle Stimulators
The FDA regulates the sale of all electric muscle stimulators in the US.
Firms must comply with their premarket regulatory requirements before they are able to sell their stimulators.
Hence, the first thing to be sure of when buying any EMS machine is that FDA clearance.
All of the muscle stimulators on this page have been cleared by the FDA.
That means the companies have demonstrated to the FDA that their devices can be used safely and effectively by consumers.
The benefits of EMS for muscles
Your muscles can benefit in many different ways from using electric muscle stimulation:
1. Low Impact
One of the most appealing aspects of EMS for muscle building is that it requires no movement from the individual.
This makes it popular not only with people at the top of their fitness game, but also those with conditions that limit their ability to exercise.
Members of the Body Building community remark on using an EMS machine to work the muscles following an injury as a safe and low impact option.
2. Muscle Rehabilitation
There is evidence to suggest that EMS can retrain the muscles following injury to regain function.
A recent study conducted in Brazil found some evidence to suggest that EMS increased voluntary function in partially paralyzed muscles.
It was felt that further research was needed to find to what extent this can be achieved.
3. Muscle Atrophy
Electric muscle stimulators have been proven to be effective for those suffering from advanced diseases such as cancer, which can cause muscle weakness.
A research project in 2012 looked at preserving muscle strength of ICU patients. Results found that EMS not only helped to preserve muscle strength but also mobilize patients earlier.
4. Pain Relief
EMS is used as a pain relief option for many. A study in 2017 found that it had a positive impact on the pain of those suffering from diabetic neuropathy with pain scores decreasing after one hour of treatment.
5. Muscle Tone
Chiropractors often recommend EMS as a way to build muscle tone. Chiropractors recognize how effective the treatment can be to maintain the muscle tone following injury for faster recovery.
6. Convenient and Portable
One of the most appealing aspects of an EMS unit is the ability to transport it wherever you go!
It can be popped in your bag and taken to the gym or discreetly used at work. There are even wearable devices so you can work your muscles while on the go.
7. Treat a Range of Conditions
EMS has been shown to be effective in treating a number of conditions including Parkinson’s Disease.
Research conducted in 2017 looked at how EMS could be used to treat hand tremors in patients with the condition.
The study reported favorable results when the treatment was applied to the hand with a glove attachment.
One of the most notable conditions EMS can be beneficial for is Osteoarthritis (OA).
Research conducted in 2003 shows that EMS was effective in building strength in the knee for those suffering from OA.
It was also praised for not exacerbating painful symptoms. Further research conducted in 2013 found similar positive results.
8. Pressure Sores
Those suffering spinal cord injuries can often find themselves with pressure sores.
A study in 2014 looked at how EMS can stimulate the muscles to avoid sores and though positive results were reported it was still felt that further research is needed.
Professionals in the rehabilitation community recommend EMS to help reduce swelling of the joints following injury.
They explain how EMS causes the muscle to contract, essentially moving the swelling away from the muscle.
A focus on ab belts
Ab belts are a big hit in the exercise community as they can tone your abs while you get on with your day to day life!
They’re essentially just EMS units with pre-positioned electrodes on a belt.
Slendertone’s app driven Connect is currently the most technologically-advanced ab belt on the market:
While the main benefit of choosing an ab belt over a normal EMS device is convenience, be aware that there are some performance considerations to take into account.
The shape and position of the electrodes on ab belts have been designed to work your abs only, they’re literally made to measure!
Whereas, generic square or rectangular electrodes from standard EMS units haven’t been specifically designed to work your abs.
- The takeout here is: If the only group of muscles you want to use EMS on is your abs then get an ab belt.
One question people often ask though is do ab belts really work?
Well, the FDA seems to think so!
At this time Slendertone’s belts (they also manufacture the Flex Belt) have been cleared by the FDA to tone, strengthen and firm abdominal muscles.
Find out more about Slendertone’s devices here.
The verdict: Can a TENS unit build muscle?
So the short answer to the question, is no. However electrical muscle stimulation can.
TENS is more appropriate for pain relief, whereas EMS has been shown to be effective in muscle building and rehabilitation, though more research appears to be needed.
If it is something you’re considering purchasing then take a look at these impressive EMS machines.