Besides high acceptance and compliance, we found (significant) improvements in muscle mass, body fat, strength and power compared with a group which just continuing its conventional exercise training. 

 

Motivated by the positive results of TEST I we ventured on a more “crucial” intervention group in TEST II (Kemmler, Teschler, & Von Stengel, 2015), made up of untrained and physically inactive men (65+) with cardio-metabolic diseases and abdominal obesity. The central aim was the enhancement of lean body mass (LBM) and reduction of abdominal body fat level both total and also with a negative cardio-metabolic effect. After 14 weeks of WB-EMS (1.5 x 20 min/week) we verified (significant) differences for LBM and total body fat, as well as a tendency for reduction in abdominal fat compared with a control group (vibration training, 2 x 15 min/week). There were no effects in laboratory findings (e.g. cholesterol) or blood pressure. Beside highly significant improvements in strength and power, the interventions once again showed high attractiveness and compliance.

 

For the very elaborate TEST III study (Kemmler, Teschler, & Von Stengel, 2015), we focused on an even more vulnerable population of physical inactive women (70+) with low muscle mass and bone density. The central aim was the increment of muscle mass and bone density compared with a control group doing a low-impact functional training. After one year of intervention (WB-EMS, 1.5 x 20 min/week) TEST III showed highly relevant improvements in muscle mass/function and body fat. Effects on bone density were clearly significant, but compared with muscle mass in an unspectacular range, better comparable to mean values known from whole-body vibration. Here, we expected more obvious results, expecting a closer “muscle-to-bone interaction”. Overall, the TEST III conclusion is none the less positive, not least because we (again) had a high compliance with low dropout and high attendance.

 

Following the Formosa study, we organized a somewhat similar study to examine sarcopenic obesity in men 70+ (FranSO). During the training sessions, we dropped the supine position in favour of training in the more usual standing position. Compared with the FORMOsA study, we increased the individual protein intake to a total of 1.8 g/kg body weight.

 

After 14 weeks of WB-EMS Training (1.5 weeks / week, 12 - 20 min progressive, see above), we found significant improvements in almost all parameters. In addition to the total body fat, abdominal body fat was significantly reduced with simultaneous improvement of the skeletal muscle mass index, functional abilities (strength) and more favorable developments in the blood values ​​(e.g. cholesterol/blood fats). As in the previous study, all conditions (nutrition, physical and sporting activity) were kept stable over the intervention period.

 

A combination of both training methods, WB-EMS and endurance, is used by many coaches for enhanced effects for the cardiovascular system and especially for body fat reduction.

 

Concerning the first effect, one study (Fritzsche et al., 2010) evaluated the influence of conventional low frequency training (see above; in standing position) on cardiac and functional parameters in patients with heart insufficiency. After 6 months, the authors found an improvement in muscle physiological and metabolic parameters “by far exceeding the results of common traditional aerobic training forms”. Consequently, the combination of both methods (WB-EMS with additional endurance training) should generate optimum results, also with a certain relevance for mobile WB-EMS application. In contrast to Fritzsche et al., we primarily focused on the effect of a combined WB-EMS/endurance intervention on metabolic syndrome and energetic metabolism in overweight and obese men (Kemmler, Von Stengel, Schwarz, & Mayhew, 2012). It was also one of our aims to closely examine the “impressive” effect on body fat reduction given that WB-EMS is a training method requiring relatively litte time (1.5 x 20 min/week). To capture the energy expenditure with and without WB-EMS we used the “gold standard” method of indirect calorimetry (resp. analysis of breathing gas). We found significantly higher energy expenditure after a classic 16-min WB-EMS application with additional light movement patterns in a standing position (intermitted, 85 Hz; see above) and a similar trend for the 30-min endurance program (cross-trainer) with 60 % of maximum oxygen intake under “continuous current” (7 Hz vs. 85 Hz; 350 µs). However, this energy expenditure for the classic EMS application (107 ± 16 vs. 92 ± 17 kcal/16 min) is borderline negligable. Concerning the cross-trainer endurance program, the very low frequency (7 Hz) showed clear effects (500 ± 67 vs. 85 Hz: 476 ± 68 vs. No EMS: 450 ± 60 kcal/30 min). Especially the marginal effects from classic EMS application are somehow at odds with the obvious fat reduction with WB-EMS. Reconsidering EMS-induced higher energy expenditure, there are three possible mechanisms: (1) the energy need during acute load (see above), (2) excess post-exercise oxygen consumption (meaning intermediate effects over several hours post-training) and (3) an increased resting metabolic rate conditioned by EMS-induced increase in muscle mass. While (3), more for medium to long-term effects, plays a not inconsiderable role for weight or “fat management”, point (2) is frequently overrated because the total energy used amounts to 10 - 15 % of the immediate load.

 

Methodically debatable is the question, whether our spirometric measurement really captured the actual energy consumption during WB-EMS with the simultaneous stimulation of 2,800 cm2 of body surface (point (1)). Actually, indirect calorimetry is less suitable for measuring energy consumption during mainly local and anaerobic energy supply such as strength training or WB-EMS. More sophisticated methods should therefore be used to address this topic.

In 2015, SpiegelOnline magazine ran an article with headline “dangerous current impulses“ that aptly described the problem of (too) high initial current intensity in WB-EMS in beginners: dizziness, nausea and high creatine kinase (CK) values with corresponding possible stress for the kidneys – certainly not the best motivation for a potential user. What is the real “truth” behind these reported, almost unbelievably high, CK values after (too) intense initial application – which is certainly also a problem that could have a clinical relevance in our research area with older people. In order to clarify this problem we conducted a study with three questions (Kemmler, Teschler, Bebenek, & von Stengel, 2015; Teschler, 2016): (1) Are the CK values as high as sometimes reported in the literature after WB-EMS application to exertion (85 Hz, 20 min, intermittent, see above)? (2) Does rhabdomyolysis (muscle decay) have clinical relevance in healthy users? (3) Does regular WB-EMS lead to a reduction in CK values after exertion?

 

Question 1 can definitely be answered with a clear “yes”! In fact, we found a 117-fold increase in CK in comparison to resting value (170 IE/l). Twenty-six sporting subjects (25 - 50 y) without WB-EMS experience did one single bout of WB-EMS to exertion, with CK peaking after 3 - 4 days. The maximum value was about 144,000 IE, a result confirmed by recently reported even higher values (240,000 IE) in young professional soccer players after WB-EMS to exhaustion (Kastner, Braun, & Meyer, 2014). In fact, WB-EMS application meets all the above-mentioned criteria for training-induced CK levels such as (a) high proportion of upper body musculature, (b) high volume of exercised muscles, (c) short breaks, (d) high innervation rate, and (e) mechanical stress.

 

On the other hand, question 2 can not be answered that easily. A pronounced stress-induced (“exertional”) rhabdomyolysis is defined as values of more than 10,000 IE/l or a 50-fold increase in resting value, and can be associated with considerable health complications. Beside (heart-) muscle-related problems caused by hyperkalemia and hypocalcemia, as well as liver damage, acute renal failure is frequently reported after (trauma-induced) rhabdomyolysis. In this context, we evaluated not only parameters for rhabdomyolysis (e.g. CK, myoglobin), but also electrolytes (e.g. potassium, calcium) and kidney parameters such as creatinine concentration, glomular filtration rate, as well as traces of protein and blood in the urine. We found no abnormalities in electrolytes or for the kidneys and the urine parameters, despite a 40-fold increase in myoglobin, which is considered as “nephrotoxic“. Thus, no cause for concern? Certainly not, all our study participants were healthy, fit and well hydrated and were also guided and supervised very closely by medical staff. The extent to which an initial application to exertion can lead to renal impairment in people with poor preparation remains undecided. 

 

Turning to question 3: Due to a “repeated bout effect”, CK concentration (as guiding criteria for rhabdomyolysis) increases only about 4 - 5 fold after a 10-week conditioning training (1 x 20 min/week) and thus lies in the range of intense conventional strength training. Approaching the present topic with a certain degree of common sense, exertional CK values should not occur during the first sessions/trial session. In training, however, especially competitive/performance-oriented novices with a certain tolerance for high loads demand exactly this kind of exertional stress, a request which is often heeded by EMS trainers. Again, due to the supramaximal intensity and the large amount of simultaneously trained muscles in WB-EMS, a reckless application is particularly “prone” to provoking “exertional rhabdomyolysis” with all its associated health consequences. Therefore, a slow approach to higher current intensities should be paramount during a 4 - 6-week conditioning phase.

First studies on EMS Training already in 2008 subject to research so far (selected)

www.imp.uni-erlangen.de

 

Filipovic, A., et al. (2011). Electromyostimulation--a systematic review of the influence of training regimens and stimulation parameters on effectiveness in electromyostimulation training of selected strength parameters. J Strength Cond Res, 25(11), 3218-3238

Filipovic, A., et al. (2012). Electromyostimulation - A Systematic Review of the Effects of Different EMS Methods on Selected Strength Parameters in Trained and Elite Athletes. J Strength Cond Res, 26(9), 2600-2614

 

Fritzsche, D., Fruend, A., Schenk, s., Mellwig, K.P., Kleinöder, H., Gummert, J., et al. (2010). Elektromyostimulation (EMS) bei kardiologischen Patienten. Herz 35, 34 - 40.

 

Kastner, A., Braun, M., & Meyer, T. (2014). Two Cases of Rhabdomyolysis After Training With Electromyostimulation by 2 Young Male Professional Soccer Players. Clin J Sport Med.

 

Kemmler, W., Teschler, M., Bebenek, M., & von Stengel, S. (2015). [(Very) high Creatinkinase concentration after exertional whole-body electromyostimulation application: health risks and longitudinal adaptations]. Wien Med Wochenschr, 165(21-22), 427-435.

 

Kemmler, W., Teschler, M., & Von Stengel, S. (2015). Effekt von Ganzkörper-Elektromyostimulation – “A series of studies“. Osteologie 23(1), 20-29.

 

Kemmler, W., Teschler, M., Weissenfels, A., Bebenek, M., von Stengel, S., Kohl, M., et al. (2016). Whole-body electromyostimulation to fight sarcopenic obesity in community-dwelling older women at risk. Resultsof the randomized controlled FORMOsA-sarcopenic obesity study. Osteoporos Int, 27(11), 3261-3270.

 

Kemmler, W., Teschler, M., Weissenfels, A., Fröhlich, M., Kohl, M., & S., Von Stengel. (2015). Ganzkörper-Elektromyostimulationst versus HIT-Krafttraining - Effekte auf Körperzusammensetzung und Muskelkraft. Dtsch Z Sportmed, online first.

 

Kemmler, W., Von Stengel, S., Schwarz, J., & Mayhew, J. L. (2012). Effect of whole-body electromyostimulation on energy expenditure during exercise. J Strength Cond Res, 26(1), 240-245.

 

Stefanovska, A., & Vodovnik, L. (1985). Change in muscle force following electrical stimulation. Dependence on stimulation waveform and frequency. [Comparative Study Research Support, Non-U.S. Gov‘t]. Scand J Rehabil Med, 17(3), 141-146.

 

Teschler, M.; Weissenfels, A.; Fröhlich, M.; Kohl, M., Bebenek, M.; von Stengel, S.; Kemmler, W. (2016). (Very) High creatine kinase (CK) levels after Whole-Body Electromyostimulation. Are ther implications for health? Int J Clin Exp Med, 9(11), 22841-22850.