Recent news reports highlighted a government crackdown on companies purveying ‘effortless’ exercise via ubiquitous infomericals for various kinds of electronic muscle stimulators. Among the claims made for the devices was that using them for just 15 minutes a day led to results that equaled doing ‘hundreds of situps.’ Many of the infomericals noted in easily missed small print that ‘best results occur when used in conjunction with a low-calorie diet.’
The government finally had enough of such spurious claims and went after a few of the more profitable electric muscle-stimulator outfits. Amazingly, one company denied misleading the ingenuous consumers who purchased its machines. No doubt the company alleged innocence based on research showing that some electrical muscle stimulators actually do provide a degree of genuine muscle stimulation.
Electric muscle-stimulating machines enjoyed a peak of popularity among bodybuilders and other strength athletes in the early ’70s. At that time a Russian scientist named Kots claimed that using electrical muscle machines with a specific intensity protocol worked better than merely lifting weights in increasing muscle strength and size in elite athletes. Since the Soviet athletes had a virtual hegemony in international athletic competition, particularly strength sports, Kots’ claims weren’t ignored.
One reason electrical muscle-stimulating machines were thought to provide an advantage over ordinary exercise was that they reversed muscle-recruitment patterns. Normally, the body initially recruits the smaller and weaker type 1, or slow-twitch, muscle fibers, only recruiting the larger type 2 fibers when the type 1 fibers begin to fatigue. With electrical muscle stimulation, however, the larger type 2 fibers were recruited first. Since the type 2 fibers are largely responsible for muscle size and strength increases, it’s easy to understand why electrical stimulation soon became a fad among those seeking muscle gains.
Later studies showed that the machines provided no true advantage’and a few notable disadvantages’over conventional weight training. For one, you needed to have a certain level of voltage to properly work a muscle’at least 60 percent of the maximum-muscular-contraction level of intensity’and many machines didn’t approach that minimum, thus making them ineffective.
Still, the promise of building muscles and even losing fat through relatively effortless exercise has never actually faded away. Many people are just too lazy to engage in the type of exercise and diet that will give them the results they seek and so are open to a seemingly easy way to the same goals. As with most things in life, the easy route never really works.
The point is illustrated in a new study that examined the effects of an electrical muscle-stimulation machine, presently on the market, on body composition, strength and physical appearance.1 Twenty-seven college students were assigned to either a muscle-stimulation-machine group or a control group that used a similar-looking machine that provided no electrical stimulation. Those in the actual machine group used the devices three times weekly in accordance with the manufacturer’s instructions. They trained various muscle groups, including the hamstrings, quads, biceps, triceps and abdominals. Their results were determined by a battery of body-composition tests and before-and-after photographs.
After eight weeks the subjects using the actual electrical muscle stimulators showed no significant results compared to the control group. The authors noted that the machines were of poor quality (generally the case for any exercise machine sold through infomericals). The machines also did not allow a precise voltage or intensity adjustment, leading to premature fatigue of the exercised muscle fibers. In addition, despite the claims of ‘quick, effortless workouts,’ the machines proved uncomfortable, and the workouts required at least 45 minutes, leading most of the study participants to note that they would rather have gone to the gym. Perhaps worst of all, the machines did not provide the minimal level of intensity required to elicit muscle gains, thus making them useless.
That’s not to say that all electrical muscle-stimulating machines are useless. Those used in medical settings, such as by trained physical therapists, are of far better quality than the junk sold on late-night TV and can help to prevent muscle atrophy during required limb immobilization. And those far more sophisticated machines do provide the correct level of muscle-stimulation intensity, although they are not superior to normal weight training in terms of promoting size and strength gains.
1 Porcari, J.P., et al. (2002). Effects of electrical muscle stimulation on body composition, muscle strength and physical appearance. J Strength Cond Res. 16:165-172.