Whole-Body Electromyostimulation – The Need for Common Sense! Rationale and Guideline for a Safe and Effective Training
Ganzkörper-Elektromyostimulation – eine Richtlinie zur sicheren und effektiven Anwendung
Whole-body electromyostimulation (WB-EMS) is a young and time-effective training technology. Comparing the effect of WB-EMS with conventional resistance training,both methods were reported to be similarly effective on muscle mass, strength and cardiometabolic risk. However, due to its exceptional time efficiency, joint friendliness and individualized setting, WB-EMS may be a good choice for people unable or simply unwilling to conduct intense resistance training protocols.
However, recent literature has reported negative side-effects concerning WB-EMS-induced rhabdomyolysis. Indeed, due to the ability to innervate large muscle areas simultaneously with dedicated individual intensity per muscle group, WB-EMS features many factors known to be associated with muscle damage. A recent WB-EMS study applying an initial application to exhaustion to healthy novices confirmed the reported exceptionally high creatine-kinase (CK) concentrations. Although the study did not detect any of the reported clinical consequences of this “severe” rhabdomyolysis (i.e. ≥50fold increase of resting CK), in less fit subjects who were neither optimally prepared nor supervised, initial WB-EMS to exertion may have more far-reaching consequences.
Of importance, a subsequent WB-EMS conditioning phase of 10 weeks completed by a second WB-EMS test application to exhaustion demonstrated CK-peaks in the range of conventional resistance exercise.
Thus, in summary (a) too intense initial WB-EMS may indeed result in a severe rhabdomyolysis (b) thus, initial WB-EMS application to exhaustion must be strictly avoided, and (c) frequent WB-EMS application demonstrated a very pronounced repeated bout effect after a short conditioning phase.
KEY WORDS: Electrostimulation, Creatine-Kinase, Rhabdomyolysis, Recommendation WB-EMS
Ganzkörper-Elektromyostimulation (WB-EMS)erfreut sich durch Zeiteffizienz, Individualisierbarkeit und Effektivität zunehmender Beliebtheit. In jüngster Vergangenheit wurden nach Erstanwendung von WB-EMS in Einzelfällen jedoch (extrem) hohe Kreatinkinase (CK)-Werte berichtet, die in einem gesundheitlich bedenklichen Bereich liegen. Bedingt durch die flächige simultane Applikation mit dezidierter Ansteuerung der Stimulationsflächen treffen für WB-EMS durchaus die meisten Voraussetzungen für eine „exertional Rhabdomyolysis“, also eine ausgeprägte körpertrainings-induzierte Muskelschädigung zu.
Tatsächlich zeigte eine kürzlich erschienene Untersuchung mit gesunden Sportlern ohne WB-EMS Vorerfahrung nach ausbelasteter, also hochintensiver, WB-EMS-Erstapplikation eine 117-fache Erhöhung der CK-Konzentrations-Werte im Bereich einer schweren („severe“) Rhabdomyolyse (≥50-fache Erhöhung des Ruhe-CK). Obwohl für keinen der 26 Studienteilnehmer die in der Literatur berichten negativen renale und kardialen Indizien einer (schweren) Rhabdomyolyse vorlagen, mögen die Konsequenzen bei vorgeschädigten, leistungsschwachen und schlecht vorbereiteten Individuen deutlich dramatischer ausfallen.
Eine nachfolgende Untersuchung, welche den Effekt regelmäßigen WB-EMS-Trainings evaluierte, zeigte nach 10-wöchigem Konditionierungszeitraum und anschließender, wiederum ausbelasteter, WB-EMS-Applikation einen ausgeprägten „repeated bout effect“ mit CK-Spitzenwerten im unteren Bereich konventionellen Krafttrainings (<1000 IE/l), also in einem unbedenklichen Bereich.
Als Fazit leiten wir ab, dass (a) unsachgemäße WB-EMS-Erstapplikation durchaus negative gesundheitliche Konsequenzen haben kann, (b) eine ausbelastende bzw. sehr intensive WB-EMS-Erstapplikation in jedem Fall zu unterbleiben hat und (c) ein rascher Gewöhnungseffekt auch hinsichtlich ausbelasteter WB-EMS-Applikation auftritt. Letzteres ist zur Realisierung relevanter Effekte, vergleichbar einem konventionellen Krafttraining, nicht zwingend nötig.
SCHLÜSSELWÖRTER: Elektrostimulation, Kreatinkinase, Rhabdomyolyse, WB-EMS-Applikation
Whole-body electromyostimulation (WB-EMS) is a young and time effective training technology that focuses primarily on body composition (i.e. muscle, bone, fat tissue) and strength-related parameters (5, 7, 9, 13, 14). However, other health related outcomes (i.e. cardio-metabolic risk factors) (4) were also reported to be positively affected by WB-EMS. A direct comparison of WB-EMS and the slightly more time-consuming High Intensity (Resistance) Training (HIT) (WB-EMS: 1.5x20 vs. HIT: 2x30 min/week) has shown that both methods are similarly effective in increasing body composition, strength (7, 8) and cardio-metabolic risk (4, 8). However, due to its exceptional time efficiency (7), joint friendliness and individualized setting, WB-EMS may be a good choice for people unable or simply unwilling to conduct intense resistance training protocols. However, in a recent letter to the British Medical Journal, Malnick et al. addressed the potential risks of WB-EMS and “the need to regulate the use of whole body electrical stimulation” (11). Indeed recent scientific literature has reported negative side-effects concerning WB-EMS induced increases in creatine-kinase up to a level of severe rhabdomyolysis (i.e. >50-fold increases compared with resting levels) (1, 2, 12).
Summarizing the mechanisms of exertional rhabdomyolysis, in general WB-EMS undeniably features most of the factors known to be associated with (resistance) exercise induced muscle damage and very pronounced muscle soreness (10). Especially the outstanding feature to innervate large muscle areas (12-14 electrodes with up to 2,800 cm2) simultaneously, but with dedicated individual intensity per electrode/muscle group, may contribute to the problem of WB-EMS induced rhabdomyolysis, at least when applying too high (current) intensity. Thus, an adequate WB-EMS application is essential for preventing rhabdomyolysis and corresponding renal, hepatic and cardiac consequences.
In a recent study, we applied a typical but borderline exhaustive WB-EMS protocol (20min, bipolar, 85Hz, 350µs, rectangular, 6s of current, 4s of rest) to 37 healthy WB-EMS novices (6). And indeed, the CK increase after this borderline (too) intense initial WB-EMS application confirmed the reported exceptionally high CK-levels and very pronounced muscle soreness from 48h-96h (6). In detail, CK-concentration rose 117-fold (28545±33611 IU/l) with a peak after 72h and was 10 times higher compared with the CK-levels after a marathon run that was monitored in parallel (2795±883 IU/l after 48h). Although, we did not detect any of the reported clinical consequences of this “severe” rhabdomyolysis on renal and cardiac risk factors (15), in less fit and healthy subjects neither optimally prepared nor supervised, initial WB-EMS to exertion may have more far-reaching consequences.
Significantly, a subsequent WB-EMS conditioning phase of 10 weeks (1x20min WB-EMS/week, see above) completed by a second WB-EMS test session to exhaustion demonstrated a very pronounced “repeated bout effect” with individual CK-peaks all below 2000 IU/l (MV±SD: 906±500 IU/l), i.e. in the lower range of conventional resistance exercise training (6, 10). This result indicates that a short period of careful WB-EMS conditioning should be mandatorily implemented in order to realize a safe application.
We conclude that the problem of WB-EMS induced rhabdomyolysis can be easily prevented with a minimum of common sense. Firstly, although some groups of highly motivated WB-EMS novices may request an exertional initial WB-EMS application, this approach should be strictly avoided. In parallel, no clear-thinking instructor would apply an intense eccentric resistance training protocol to muscular failure during the initial session to a resistance training novice. Secondly, as with conventional resistance exercise there is no need to focus on WB-EMS to exhaustion in order to generate relevant effects on body composition and functional capacity (3, 7). Additionally, contraindications for WB-EMS should be strictly heeded and WB-EMS novices adequately informed so as to ensure a safe and successful WB-EMS application. In order to realize the latter aim, in a German consensus conference in December 2015, WB-EMS manufacturers (miha-bodytec, Gersthofen, Germany), educational institutions (GluckerKolleg, Kornwestheim, Germany), Licensees (PT Lounge Köln, Cologne, Germany) and publishing researchers (see below) discussed the topic. Finally in April 2016, the scientific part of the consortium (Fröhlich, M.; Kemmler, W.; Kleinöder, H. v. Stengel, S.) has formulated a general guideline, that we would like to disseminate and publish here. We are aware that WB-EMS is a young and innovative technology with considerable further potential, thus extensions and changes of this guideline may be necessary in the nearest future. However, we think the general recommendations listed may be a first step to a more safe and effective WB-EMS application.
Conflict of Interest
The authors are aware that some commercial partners may have had a conflict of interest with respect to some issues. However, the final responsibility for the generation of this guideline clearly lies by the authors.
- Severe rhabdomyolysis after mihabodytec(R) electrostimulation with previous mild hyper-CKemia and noncompaction. Int J Cardiol. 2015; 180: 100-102.
- Two Cases of rhabdomyolysis after training with electromyostimulation by 2 young male professional soccer players. Clin J Sport Med. 2014; 25: 71-73.
- Impact of whole-body electromyostimulation on body composition in elderly women at risk for sarcopenia: the Training and ElectroStimulation Trial (TEST-III). Age (Dordr). 2014; 36: 395-406.
- Effects of high intensity resistance training versus whole-body electromyostimulation on cardiometabolic risk factors in untrained middle aged males. A randomized controlled trial. J Sports Med. 2016; [accepted for publication].
- Effects of whole-body-electromyostimulation on resting metabolic rate, anthropometric and neuromuscular parameters in the elderly. The Training and ElectroStimulation Trial (TEST). J Strength Cond Res. 2010; 24: 1880-1887.
- Hohe Kreatinkinase-Werte nach exzessiver GanzkörperElektromyostimulation: gesundheitliche Relevanz und Entwicklung im Trainingsverlauf. Wien Med Wochenschr. 2015; 165: 427-435.
- Effects of whole-body electromyostimulation versus high-intensity resistance exercise on body composition and strength: A randomized controlled study. Evid Based Complement Alternat Med. 2016; 2016: 9236809.
- Ganzkörper-Elektromyostimulationst versus HIT-Krafttraining - Effekte auf Körperzusammensetzung und Muskelkraft. Dtsch Z Sportmed. 2015; 66: 321-327.
- Whole-body electromyostimulation as a means to impact muscle mass and abdominal body fat in lean, sedentary, older female adults: subanalysis of the TEST-III trial. Clin Interv Aging. 2013; 8: 1353-1364.
- The creatine kinase response to resistance exercise. J Musculoskelet Neuronal Interact. 2014; 14: 68-77.
- It‘s time to regulate the use of whole body electrical stimulation. BMJ. 2016; 352: i1693.
- Rhabdomyolysis. Crit Care Clin. 1999; 15: 415-428.
- Whole-Body electromyostimulation to fight osteopenia in elderly females: The randomized controlled Training and Electrostimulation Trial (TEST-III). J Osteoporos. 2015; 2015: 643520.
- Effects of loaded squat exercise with and without application of superimposed EMS on physical performance. J Sports Sci Med. 2016; 15: 26-33.
- Rhabdomyolysis: review of the literature. Neuromuscul Disord. 2014; 24: 651-659.
Friedrich-Alexander University Erlangen
(FAU), Institute of Medical Physics
91054 Erlangen, Germany