Effects of Whole-Body Electromyostimulation on Strength-, Sprint-, and Jump Performance in Moderately Trained Young Adults: A Mini-Meta-Analysis of Five Homogenous RCTs of Our Work Group

Abstract

Background: Whole-body electromyostimulation (WB-EMS) gained increasing interest in sports within recent years. However, few intervention studies have examined the effects of WB-EMS on trained subjects in comparison to conventional strength training.Objective: The aim of the present mini-meta-analysis of 5 recently conducted and published randomized controlled WB-EMS trails of our work group was to evaluate potentially favorable effects of WB-EMS in comparison to conventional strength training.Methods: We included parameter of selected leg muscle's strength and power as well as sprint and jump performance. All subjects were moderately trained athletes [>2 training sessions/week, >2 years of experience in strength training; experimental group (n = 58): 21.5 ± 3.3 y; 178 ± 8 cm; 74.0 ± 11 kg; control group (n = 54): 21.0 ± 2.3 y; 179.0 ± 9 cm; 72.6 ± 10 kg]. The following WB-EMS protocols were applied to the experimental group (EG): 2 WB-EMS sessions/week, bipolar current superimposed to dynamic exercises, 85 Hz, 350 μs, 70% of the individual pain threshold amperage. The control groups (CG) underwent the same training protocols without WB-EMS, but with external resistance.Results: Five extremely homogenous studies (all studies revealed an I2 = 0%) with 112 subjects in total were analyzed with respect to lower limb strength and power in leg curl, leg extension and leg press machines, sprint—and jump performance. Negligible effects in favor of WB-EMS were found for Fmax of leg muscle groups [SMD: 0.11 (90% CI: −0.08, 0.33), p = 0.73, I2 = 0%] and for CMJ [SMD: 0.01 (90% CI: −0.34, 0.33), p = 0.81, I2 = 0%]. Small effects, were found for linear sprint [SMD: 0.22 (90% CI: −0.15, 0.60), p = 0.77, I2 = 0%] in favor of the EMS-group compared to CON.Conclusion: We conclude that WB-EMS is a feasible complementary training stimulus for performance enhancement. However, additional effects on strength and power indices seem to be limited and sprint and jump-performance appear to be benefiting only slightly. Longer training periods and more frequent application times and a slightly larger stimulus could be investigated in larger samples to further elucidate beneficial effects of WB-EMS on performance parameters in athletes.

Efficacy of Whole-Body Electromyostimulation (WB-EMS) on Body Composition and Muscle Strength in Non-athletic Adults. A Systematic Review and Meta-Analysis

“…Further, one should consider that the present results were only attributable to WB-EMS protocols that focus on moderate to high impulse intensity and low to negligible voluntary workload, an approach to our best knowledge used by the vast majority of commercial and clinical WB-EMS settings, however. Deviating from our results, a previous (mini) meta-analysis (Wirtz et al, 2019) that addressed superimposed WB-EMS with high intensity voluntary workload protocols in athletic cohorts, resulted in non-significant WB-EMS effects. This result might relate to the problem of detecting small but nevertheless important changes in performance parameters in athletic cohorts with their limited potential for further improvements.…”

“…However, while most protocols use similar impulse settings (e.g., bipolar, 80-85 Hz, 300-400 µs, intermitted), two fundamentally different WB-EMS concepts have evolved and should be considered when classifying WB-EMS. One strategy predominately used in athletic performance (e.g., Filipovic et al, 2015Filipovic et al, , 2016Filipovic et al, , 2019Wirtz et al, 2016Wirtz et al, , 2019Amaro-Gahete et al, 2018a,b;Micke et al, 2018;Ludwig et al, 2020), but rarely applied in the health and fitness domain (Amaro-Gahete et al, 2019a;Pano-Rodriguez et al, 2020a,b), combined different stimulation parameters (i.e., frequencies, pulse width, and current cycles) and prescribes high voluntary loads superimposed by WB-EMS with an impulse intensity that just allows the proper application of the target exercise (e.g., weighted squats, jumps). In diametric contrast, the more popular WB-EMS strategy, almost exclusively applied by commercial WB-EMS suppliers, focuses on negligible to low 1 effort voluntary workload by gentle movements and (adjuvant) moderate-high impulse intensities, i.e., "electric current" not voluntary workload providing the dominant effect.…”

“…Correspondingly, most studies determined the effect of WB-EMS on lean body mass (LBM), muscle strength, and function (e.g., Kemmler et al, 2014Kemmler et al, , 2016bAmaro-Gahete et al, 2019a;Jee, 2019;Pano-Rodriguez et al, 2020a), but also on body fat (e.g., Vatter, 2010;Kemmler et al, 2018a;Schink et al, 2018;Jee, 2019;Bellia et al, 2020;Ricci et al, 2020) and less frequently, albeit largely successfully, to address cardiometabolic parameters (e.g., Kemmler et al, 2016c,d;Jee, 2018;Bellia et al, 2020) and metabolism (e.g., Kemmler et al, 2010bKemmler et al, , 2012. In parallel, although several studies focus on athletic performance in younger adults (e.g., Filipovic et al, 2016Filipovic et al, , 2019Amaro-Gahete et al, 2018b;D'Ottavio et al, 2019;Wirtz et al, 2019;Ludwig et al, 2020), the vast majority of WB-EMS trials address the health and fitness domain in predominately untrained, middleaged to older adults (Kemmler et al, 2020b). This core client group of commercial WB-EMS providers (EMS-Training.de, 2017) might be predominately attracted by the perceived time efficiency, low mechanical demands, joint "friendliness, " 2 and individual scalability (Kemmler et al, 2020b) of this training technology.…”

Eletroestimulação De Corpo Inteiro: Uma Breve Revisão Narrativa Sobre Seus Benefícios E Riscos/Whole-Body Electrostimulation: A Brief Narrative Review of Its Benefits and Risks

“…Recente estudo de revisão sistemática e meta-análise [17], reuniu 5 estudos publicados cujo objetivo foi avaliar efeitos potencialmente favoráveis do WB-EMS em comparação ao treinamento de força tradicional sobre o desempenho de força, sprint e altura de salto em adultos jovens moderadamente treinados. Os protocolos WB-EMS foram aplicados aos grupos experimentais, adicionalmente ao treinamento de força tradicional, 2x por semana através de corrente bipolar sobreposta a exercícios dinâmicos, 85 Hz, 350 μs, e 70% da amperagem do limiar de dor individual.…”

“…Ao final, os autores [17] concluíram que a WB-EMS é um estímulo de treinamento complementar viável para melhoria de desempenho, proporcionando efeitos adicionais nos índices de força, potência e no desempenho do sprint e altura do salto (mesmo que de forma discreta). Os pesquisadores ainda advogam que mais pesquisas são necessárias para elucidar o tema em questão.…”