Posted by: PFB
Q: What do you think about electronic muscle stimulation (EMS) as well as the new electric stim ab gizmos that are so popular today? Does it really work?
A: I get alot of these questions, especially because of the many ads on television. Okay, let's start with the first part of your question. Four applications of EMS include:
1) Strength - 10 sets of 10 seconds high intensity followed by 50 seconds of rest is Kots' protocol used by Francis and others to promote strength gains (of up to 20% ).
2) Recovery - at low intensities, EMS provides a "massaging" effect facilitating removal of waste products and delivering nutrition to the muscles through an increase in local blood supply (Siff & Verkhoshansky).
3) Rehabilitation - will retard atrophy and maintain strength by providing neural input to muscle and can relieve pain and reduce spasm (Siff & Verkhoshansky).
4) Assessment - since EMS recruits white fibers first, a fast-twitch dominant muscle will activate at lower intensities (Lindsay).
For a more detailed description of EMS refer to the following articles:
1) Macrocurrent and Microcurrent
Electrostimulation in Sport by Dr. Siff.
2) The Truth About EMS. Electronic Muscle Stimulation: Facts and Fallacies by Charlie Francis.
As well, two excellent books to read on this subject from the same authors mentioned above are:
1) Francis, C. "Training
for Speed." Australia: Faccioni Speed & Conditioning Consultants,
2) Siff, MC, Verkhoshansky, YV. "Supertraining (4th Edition)." Denver, CO: Supertraining International, 1999.
Now, problems with ab stim machines that are currently popular include the following:
These machines are deceptive in that the transient effect of localized water loss gives the appearance of weight loss, but this is short-lived once re-hydrated. From Supertraining, 1999: "Low-intensity EMS can rapidly reduce swelling ... its effectiveness may be due to the pumping action of muscle and/or the creation of an electric gradient across the cell membranes, which triggers the lymphatic system to absorb excess fluid." (pg. 211)
Remember, you cannot spot reduce; you must train the entire system (not just one area.) With that said, it is far better to do a set of 20 squats that works almost every muscle in the body than to do as many as 200 sit-ups or even receive up to 2000 twitches from an EMS unit for that matter.
Also, prolonged application of submaximal EMS can increase muscular endurance but it will not promote hypertrophy. As you know, the more muscle you have, the higher the metabolic rate. Furthermore, I have seen no studies which indicate that EMS at any level will facilitate lipolysis or fat-burning. Adaptations from EMS are very different from those of voluntary contractions - the infomercials make you believe otherwise!
Far too many people are looking for an easy way out, a magic pill if you will. Although enticing, sitting on your couch watching reruns with a bag of chips in one hand, a pop in the other, and some electrodes connected will do nothing to your bulging midsection. It comes down to diet and exercise, plain and simple.