Bionic Gym - Is it Good for Exercise?

The snapshot

Report of the Evidence, an Independent Academic Viewpoint.

Man using Bionic Gym

      The full picture

      BIONIC GYM is a wearable device that uses Electrical Muscle Stimulation (EMS) technology to initiate a shivering response as a result of muscle contractions leading to energy expenditure. It is claimed the BIONIC GYM mimics an aerobic training workout that can exceed 500 kcal per hour. The following is a review of the science that supports the claims which has been informed by a detailed examination of the products website and promotional material. I also have personal expertise in the use of EMS related products and have conducted similar reviews of evidence.

      The benefits of EMS use in medicine and sport is undisputed due to a wide body of research that has increased exponentially from the 1980's including early studies showing effectiveness with treating and preventing muscle atrophy (i.e. a reduction in muscle mass, Nitz and Dobner, 1987) and improving muscle strength (due to an increase in muscle size, Currier and Mann, 1983). However, the use of EMS for eliciting cardiovascular improvements and the associated energy expenditure is less well established, especially in activity that is unloaded.

      Caulfield et al (2004) posited that unloaded EMS activity could provide an attractive alternative to traditional forms of aerobic exercise that involve repetitive joint loading (e.g. jogging or running). It could also be used to provide a training response in people who experience barriers to undertaking voluntary weight-bearing exercise such as people with degenerative joint diseases (arthritis), obesity or spinal cord injury. They therefore developed a novel EMS system to initiate a cardiovascular response requiring minimal gross movement or loading of the limbs or joints. The pattern of EMS used in this investigation was modelled on shivering, which is the natural process for generating heat when body temperature falls.

      Using a case study design, Caulfield et al (2004) recruited a single male participant (age 31 years, body mass 70kg) who undertook 4 EMS sessions over a two-week period. Sessions were performed at the same time each day with the same electrode positioning and food intake. The output stimulus intensity of the stimulator was increased by intervals of 10% every three minutes to reach maximum output during each 30-minute session. They also completed one single EMS session of 4 hours duration whilst watching television in a seated position.

      All stimulation sessions were tolerable with no discomfort recorded. The toleration of the stimulus, both in time and intensity, was only limited by their fatigue and tachypnoea, tachycardia, sweating, and fatigue were all present at higher stimulation intensities. Average oxygen consumption (ml/kg/min) and heart rate (beats/min) at each stimulation level during each of the four 30-min sessions were recorded and there was a clear repeatable linear dose response relationship between stimulus intensity and the physiological responses. This means that as the intensity increased so did the heart rate and oxygen consumption and was consistent with responses that would be expected in voluntary exercise such as cycling or running. Oxygen consumption was 5 METs (17.5 ml/kg/min) and 10 METs (35 ml/kg/min) at 40% and 80% of maximum stimulus intensity respectively. This was associated with corresponding mean heart rate responses of 93 and 163 beats/min typically seen during aerobic exercise. The participant also exhibited very high cumulative energy expenditure during one prolonged session without any adverse effects.

      Based on the findings of only one person, it cannot be ascertained if stimulation at high intensities would prove acceptable to all as there is a great deal of individual variability in terms of reported comfort levels when using EMS (DeLitto et al 1992). However, tolerance for sub-maximal stimulation (40% of maximal output) using this form of EMS has been confirmed in a group of 10 healthy adults (Banerjee et al, 2003). This sub-maximal stimulation was associated with an average exercise workload of approximately 4 METs (14 ml/kg/min).

      BIONIC GYM was invented by Dr Louis Crowe who felt fatigued from the shivering experienced after cold water swimming. Shivering is the bodies defence against a decline in core body temperature to create heat which requires energy expenditure.  As you get colder you shiver more intensely but the rate which is typically 7-8Hz stays the same as energy expenditure is not related to the force or tension generated but the shortening and lengthening of an increased number of muscle fibers.  BIONIC GYM specifically focusses on stimulating the motor-neurons (nerves-to-muscles) in the quadriceps and rectus femoris (legs) and gluteal muscles (bum) since these are the largest muscles in the body. The muscles contract repeatedly without conscious effort and the evidence shows that BIONIC GYM induces enough muscle activity to evoke a suitable enough increase in heart rate. This effectively increase the rate of blood supply, oxygen and nutrients to the working muscles so the cardiovascular system (heart and blood vessels) work harder to deliver this blood evoking a training response similar to exercise.  

      From observing the promotional videos, BIONIC GYM is wrapped around the legs. The stimulation intensity is then controlled via an app on your phone. It appears that at low levels of intensity that would be equivalent to walking users can work at a computer, either sitting or standing or watch television. However, I anticipate that as you increase the intensity you would begin to sweat more and it would become more difficult to focus on your work.

      BIONIC GYM could be used by athletes who are injured as part of their rehabilitation and would be an attractive alternative for those in sport who have a high requirement for cardiovascular exercise training yet wish to minimise the amount of repetitive joint loading they place upon their body. There are many other potential applications for this form of EMS including helping people with limited mobility or people with overweight or obesity. However, there are no specific studies that have examined the efficacy of the BIONIC GYM for promoting weight loss to my knowledge. Further work needs to be undertaken to investigate the mechanism of action of this form of EMS and to quantify its effects in different populations.

      BIONIC GYM should not be used as a replacement for physical activity due to the many  other benefits associated with an active lifestyle including improvements in blood pressure, cholesterol as well as the psychological and social benefits. However, the science to date supports that using BIONIC GYM leads to a significant cardiovascular and energy expenditure response. 


      Banerjee, P. et al (2003). Can electrical muscle stimulation of the legs produce cardiovascular exercise? Journal of Heart Disease Abstracts, 3, 61.

      Caulfield, B. et al. (2004). The use of electrical muscle stimulation to elicit a cardiovascular exercise response without joint loading: A case study. Journal of Exercise Physiology, 7(3). 84-88.

      Caulfield B et al (2011). Clinical application of neuromuscular electrical stimulation induced cardiovascular exercise. Engineering in Medicine and Biology Society. 3266-3269.

      DeLitto A et al (1992). A study of discomfort with electrical stimulation. Physical Therapy, 72, 410-424.

      Nitz, A.J. and Dobner, J.J. (1987). High intensity electrical stimulation effect on thigh musculature during immobilization for knee sprain. Physical Therapy, 67(2), 219-222

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        Sheffield Hallam University

        Review completed and approved for use by Sheffield Hallam University


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