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Slendertone is an electrical muscle stimulation device (EMS). This means that a mild electrical current produced by the device forces involuntary contractions from your muscles. Advertisements for commercial EMS systems, including Slendertone, claim these devices will help tone and strengthen muscles. However, there is little consensus in the medical community regarding EMS devices. Although muscle contraction is the key factor is building muscle mass, the question becomes: Does Slendertone offer a way to effectively work out and improve muscle tone?


Slendertone is a device produced by manufacturer Bio Medical Research Ltd. According to the company website, Slendertone uses electrical stimulation to induce deep contractions in muscle tissue that mimics exercise. This technology has been a factor in muscle rehabilitation for decades. Bio Medical claims clinical trials from a number of educational facilities, including the University of Wisconsin, the University of Limerick and Longhborough University of Technology, prove the safety and effectiveness of Slendertone. However, they do not list details of the studies.


The U.S. Food and Drug Administration (FDA) regulates the marketing and sale of EMS devices. The agency admits that EMS products, such as Slendertone, do help to strengthen and tone muscles. However, manufacturers, including Bio Medical Research, must provide documentation to the FDA of the safety and effectiveness of their products before retailing in the United States. Slendertone uses gel patches to protect the skin from burns, a concern with electrical exercise units. The gel also serves as a conductor for the current. The basic layout of Slendertone is derived from technology used in similar therapeutic devices for muscle rehabilitation that have proven effective. In 2002, the Journal of Strength and Conditioning Research and The University of Wisconsin published the results of a trial testing the effectiveness of EMS devices to improve muscle strength and decrease body weight. Students in the study filled out questionnaires regarding the experience. Many participants concluded that they felt a difference after using the exerciser.


Although the FDA admits that this product will work to improve muscle tone, the effect may be only temporary. It does not support the use of Slendertone for weight loss. The FDA’s consumer report on EMS devices states that there is no authoritative scientific data that Slendertone will help reduce girth or increase muscle mass, and the 2002 study from the University of Wisconsin failed to prove that EMS devices improve muscle tone or show any significant effect.

Safety often becomes a factor with stimulation devices. The FDA states that multiple accounts of burns, shocks and irritation have been attributed to EMS units, although they do not mention Slendertone specifically. The sensation of electrical stimulation may be uncomfortable for some individuals. Additionally, EMS devices do not work well for those who are obese as the fat layers interfere with muscle contraction.


For an EMS device, the design of Slendertone is well-researched and possibly helpful for the right person. For a fit individual, it may improve muscle tone. Since weight loss requires you to burn more calories than you eat, however, it is doubtful that a product such as Slendertone will help in this effort, as it will not burn fat. Instead, talk to your doctor about developing a diet and fitness plan right for you. The best way to lose weight is through balanced nutrition and exercise that raises the heart rate.