I've seen commercials of "TENS" (Transcutaneous electrical nerve stimulation) devices that you strap on to your stomach or thighs, which zaps you continuously making your muscles contract, supposedly burning calories.

I'm somewhat of a lazy tub myself, so if this worked it would be a miracle device; slimming me down and working on my six pack whilst I'm at work programming.

Obviously I'm highly skeptical of this wonder-machine, hence Skeptics

Open fire!

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    unlinkable (on an old tv show) study on very small set (2 testees and 2 controls IIRC) I recall showed that it would tone muscles but doesn't burn extra calories (it's no cardio/endurance training). In other words you won't lose weight but muscles would become more defined Commented Jun 26, 2011 at 1:17
  • Low levels of electricity can be used to activate muscles, but high levels of electricity can also cause permanent damage (e.g., the electric chair used to execute criminals). These products are targeting lazy people who want to exercise without getting off the couch, and I'd worry that pro-longed use of these low-power devices to exercise might cause damage to muscles at a very slow rate. Commented Jun 26, 2011 at 3:01
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    What causes the muscle to work doesn't really matter for the effects. The differences are in how the muscle works and how much. In other words, for this to burn calories in the same way as exercise, it has to make the muscles work the same way as exercise and this will feel like exercise. Most notable, you'll get just as tired. This devices also will likely use much fewer muscles than exercising, meaning these few muscles have to work very hard. If you want to burn calories while programming, I suggest working on an exercise bike. :-) (No, I haven't tried it). Commented Jun 26, 2011 at 7:54
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    @Randolf The claim that this targets lazy people isn’t entirely correct. It is also used in medical scenarios (rehabilitation) and sports. Of course, that doesn’t mean that it actually works (though I suspect it does). Commented Jun 27, 2011 at 10:28
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    @Konrad Rudolph: I agree (+1), but I just can't imagine a medical professional buying these products from infomercials. Commented Jun 27, 2011 at 11:21

1 Answer 1


From Vanderbilt University:

There is no doubt in the medical community that it is possible to transcutaneously, that is, through the skin, stimulate nerves.

A variation of EMS (electrical muscle stimulation) is transcutaneous electrical nerve stimulation (TENS). TENS is a pain management system that uses less intense shocks to block pain signals.

The question about EMS is can it really burn enough calories to reduce a waistline, decrease body fat, and strengthen muscles?


A full research study was conducted at the University of Wisconsin and published in 2002 by "Porcari et al".

The study was to test the claims of EMS manufactures on there marketing of "rock-hard abs" and other weight loss claims.

They took 29 college aged students that had not been in a formal exercise program within the past 6 months and assigned them to either a treatment EMS group or a control group that was given faulty EMS equipment.

The groups came in to use it 3 times per week for 8 weeks.

The subjects used the device on five muscle groups:

  • bilateral biceps
  • triceps
  • quadriceps
  • hamstrings
  • abdominal muscles

muscle groups


The results showed no significant changes in weight, percent body fat, girth or strength of the treatment areas.

The EMS device did not work for any of the claims.

table 1 table 2

In the United States EMS devices are regulated by the FDA:

The use of these electrical devices in health clubs, beauty salons and figure salons has been increasing for several years.

While there are legitimate uses for both muscle stimulators and iontophoresis devices, they are prescription devices and are misbranded when labeled for lay use.

In addition, muscle stimulators are misbranded when any of the following claims are made:

  • girth reduction
  • loss of inches
  • weight reduction
  • cellulite removal
  • bust development
  • body shaping and contouring
  • spot reducing
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    +1 Excellent! I particularly liked the last part that includes the FDA's statement about these being misbranded [medical] prescription devices -- it would be good to see more enforcement to stop the marketers though, especially when they get on TV infomercials. Commented Jun 29, 2011 at 3:25
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    It makes sense that these wouldn't work - when you exercise manually, you are using your own energy to power your muscles. With these devices, your muscles are only contracting because of stimulation from an external power source. People are deceived in thinking that muscle contraction = burning calories, but they fail to realize that those calories being burned aren't their own - they're from the batteries in the device.
    – Tesserex
    Commented Jun 29, 2011 at 14:15
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    @Tesserex: I don't think that's true; muscles don't contract using electrical energy, it's a mechanical process in the fibers.
    – user1770
    Commented Jun 30, 2011 at 12:21
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    Just to add to what user1770 - muscles (like the rest of the body) get their energy by turning oxygen and glucose from the blood into carbon dioxide and water.
    – bdsl
    Commented Sep 13, 2013 at 14:04

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