While I was online last week I noticed an interesting advert on a page I was on. It featured one of the worlds most famous sportsmen wearing what appeared to be a six pack shaped contraption on his already toned midriff. The product will according to the front page of it's website give you;
"The most efficient workout of your targeted body area"
using electrical muscle stimulation.
Is that so........ let's have a look shall we.
What is EMS?
Electrical muscle stimulation or EMS for short is a method used to elicit muscle contractions using electrical impulses. These impulses are generated by a device and are delivered through electrodes on the skins surface adjacent or near to the target muscle. The impulses mimic the action potential (the electrical signal from the bodies central nervous system) that cause muscles to contract.
Does EMS work?
The short answer is yes.
The research suggests EMS can be used in a number of ways;
1: It can be use as a strength training tool for both healthy subjects and athletes as it's use over time induces neuromuscular adaptations similar/complementary to conventional strength training. However this being said, the literature strongly suggests EMS should only be used in conjunction with conventional strength training and not as a complete replacement and also of course, under strict supervision.
2: It can also be used as a rehabilitation and preventive tool for partially or totally immobilized patients. EMS has been shown to preserve muscle mass and function during periods of prolonged muscle inactivity.
3: It can be used as a testing tool to evaluate neural and/or muscular function. The reason for this being EMS is able to induce standardized muscle contractions whose electrical and mechanical properties can be quantified.
So, into which category does this device fall into?
You've guessed it.....none of them!
As I've already said the website mentions the products ability to give you an 'efficient workout' but the only other reference I could find as to its purpose was in the description of a 23 minute EMS program the device comes with, which is designed to;
"tone and firm your muscles"
This meaningless set of words is essentially marketing speak for 'it does fuck all'.
But let's assume for a moment this product was designed as a strength training tool. Would it do it's job?
Of course it wouldn't. Here's why.
To improve a muscles strength a training stimulus must elicit forceful contractions. According to the literature EMS can achieve this but requires an impulse frequency of equal or greater than 50Hz. This device is only capable of delivering 20Hz and I assume this is for good reason. 50+Hz is apparently quite uncomfortable which is as much as I'd expect given the fact these frequencies produce significant muscle contractions. According to the website the product produces a small tingling sensation and you can use it whilst you're shopping, working, commuting, cooking or relaxing!
So why use the 20Hz frequency?
The one page on the website that refers to any research highlights a 1985 study that examined various EMS frequencies. The results of that particular study supports the use of 20Hz. However, anyone who can be bothered to look it up as I did, would soon find out that it's totally irrelevant! Ignoring the age of the study and the fact that only 5 subjects were tested, it was looking at muscle fatigue after prolonged EMS (60 secs) and not changes in strength parameters. A quick look at the graphs presented show that 20hz produced a less forceful contraction but one that doesn't diminish over 60 seconds. Those using the higher frequency do diminish over this time but remember you need the more forceful contractions to elicit meaningful training adaptations and the higher frequencies produce these.
The page also rather bizarrely shows a graph of muscle oxygen saturation level over time comparing 60Hz to 20Hz. 20Hz shows less which is not surprising considering the reduced force generation and thus work output of the muscle. Apart from adding the appearance of more science to the page it's an utterly meaningless inclusion.
Another page has some pictures and graphs comparing muscle gain in those using the device to those not. However no references are sited for these so again they're completely meaningless!
The final piece of evidence thrown to the poor unsuspecting consumer has nothing to do with electrical stimulus but rather that the product integrates -
"The training theory of the worlds no. 1 footballer"
Well in that case I take it all back, it must work!
That top athlete, is Ronaldo who obviously has sports science qualifications the world was unaware of. Ronaldo's "training theory" is not explained at all but even if it was it would be about as relevant as my football theory would be to Real Madrid!
Marketing wins again
I've discussed the issue of Marketing Vs Science in a previous blog so I'm not going to re-tread that path again here but the use of Ronaldo is interesting. For one it means that the company behind this product must have significant backing. Given the enormity of Ronaldo's fame it couldn't have been cheap to get him on board. However once he does become the face of your product you're probably guaranteed a return on your investment so backing this particular donkey was I guess, a no brainer for those who did.
Not many consumers bother to investigate whether a product works or not at the best of times but if one of the worlds greatest sportsman endorses it, even less are. The simple fact that Ronaldo is associated with a product will suggest to most it must work and the sales will just pour in.
If you want to buy a set of these contraptions; one for your abdominal muscles, one for your arms and one for your legs, it will cost you about £350 and just in case you thought that sounded expensive, the gel pads that stick the device to your skin have to be replaced monthly but don't worry they only cost about £54 a set!
So let's add that up:
£350 + (12x£54) = £998 in the first year!!
With that sort of money you could buy yourself a years membership at a very nice health club, get yourself perhaps 20-30 personal training sessions, or if you want to go down market a bit about 4 years membership at your average high street gym!! So even if it did work I wouldn't exactly call it value for money.
Fitness Skeptic Score
I'm going to give 2 scores here.
One score for EMS as a tool for rehab, as an adjunct to strength training and as a tool for testing.
For that it gets an Fitness Skeptic Score of:
And another score for self administered EMS using the this device.
And that score is:
Minimal research is used to back up it's efficacy and what is seems to be irrelevant!
Please do not waste your money on this, go and get a gym membership instead!
Electromyostimulation-a systematic review of the influence of training regimens and stimulation parameters on effectiveness in electromyostimulation training of selected strength parameters. JOURNAL OF STRENGTH AND CONDITIONING RESEARCH. Nov 2011
Electrical stimulation for neuromuscular testing and training: state-of-the art and unresolved issues. European JOURNAL OF APPLIED PHYSIOLOGY. Oct 2011.
Electromechanical changes during electrically induced and maximal voluntary contractions: electrophysiologic responses of different muscle fiber types during stimulated contractions. EXP NEUROL. June 1985.
Effect of early implementation of electrical muscle stimulation to prevent muscle atrophy and weakness in patients after anterior cruciate ligament reconstruction. THE JOURNAL OF ELECTROMYOGRAPHY & KINESIOLOGY. Aug 2011.