Since the 60's Electrical MuscleStimulation (EMS) has been used primarily for rehabilitation, to prevent muscle loss (atrophy) of specific denervated muscles. However recently it has been heavily marketed as a weight loss, strength and "toning" tool. The allure of watching TV, driving or working at a desk while apparently working out is very hard to resist. In fact many have bought the AB-Tronic device or similar ab belts, clearly giving in to this temptation.
EMS comprises of a unit which basically passes an electrical current to specific muscles, via wires and electrodes that are attached superficially to the skin. While in the clinical and rehabilitation environment EMS has proven helpful to build up certain muscles which otherwise may never have been built, due to nerve or other damage, in the general population manufacturers claims have never been tested. Too often fitness products proposed to lose weight, tone up or flatten the abs, never undergo any clinical testing for effectiveness and sometimes even safety. Thus a warning light must come on after seeing or hearing claims from manufacturers even if they do not directly say it. (IE. They may "get" which means "pay" someone else to swear by the product)
Luckily there are credible, unbiased studies designed to find out whether these products work, how well they work and whether the marketing claims stand up when scientifically tested. So, "NO" manufacturers of fitness products do not have to test the effectiveness of their product and "NO" they don't have to prove that what they are marketing is the truth. What does this mean to you? Read on.
This scientific study set up two similar groups of people to put the EMS system to the test. All people in the study performed tests before being "hooked up" to this system to determine initial or what's called "baseline" measures of body composition and strength levels. Tests included things such as body weight, skinfolds to determine body fat, girths to determine muscle mass, and muscle strength tests of various muscles, obviously including ones which were to be EMSed. They tested strength levels of the biceps, triceps, quadriceps and hamstrings using various methods.
The action group then performed EMS training according to the manufacturers' description, 3 times per week for a total of 8 weeks. The control group performed "sham EMS" which acts as a placebo to remove out the strong psychological component of testing. So even the control group performed what they thought was EMS, using a more mild electrical current with "lower amplitude". After 8 weeks, the results of both groups were compared for the test parameters of body composition and strength.
After 8 weeks of "shock therapy" or Electrical Muscle Stimulation, there was no difference between groups for any of the tested parameters. Keeping in mind that the groups were identical in terms of age, height, weight or percentage body fat, this is what scientific studies unfortunately sometimes discover. So there was no difference between EMS and non EMS groups for 7 skinfolds, bodyweight, or lean body weight (muscle), percentage of bodyfat or fat weight from pre to post testing in either group. No difference were seen in girths of the various body sites tested in either group including the abdominals. Even strength levels were not elevated by EMS training.
The researchers of this study also concluded that, "there were no significant changes in the appearance of firmness or tone in either group from pre- to post testing" which runs contrary to what these manufacturers clearly state in their marketing. So the moral of the story here is not to believe everything you hear, read or are told by manufacturers, marketers and their close associates. Most give you what you want to hear. Scientific studies like this one gives and we aim to give you the truth.
The allure of watching TV, driving or working at a desk while apparently working out is very hard to resist. In fact many have bought the AB-Tronic device or similar ab belts, clearly giving in to this temptation.
After 8 weeks of Electrical Muscle Stimulation, there was no difference between groups for any of the tested parameters.
"No difference between EMS and non EMS groups for 7 skinfolds, bodyweight, or lean body weight (muscle), percentage of bodyfat or fat weight"
"No difference in girths in either group and no changes in skinfolds. For those here, how are no doubt interested, strength levels were not elevated by EMS training.
One can safely conclude that the evidence supports the hypothesis that Electrical Muscular Stimulation has no effects on body composition such as muscle mass.
REFERENCE:
Porcari, J.P., K. P. McLean, C. Foster, T. Kernozek, B. Crenshaw, and C. Swenson. Effects of electrical muscle stimulation on body composition, muscle strength, and physical appearance. J. Strength Cond. Res. 16(2):165-172. 2002