AUTHOR=Berger Joshua , Becker Stephan , Backfisch Marco , Eifler Christoph , Kemmler Wolfgang , Fröhlich Michael 

TITLE=Adjustment Effects of Maximum Intensity Tolerance During Whole-Body Electromyostimulation Training

JOURNAL=Frontiers in Physiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2019.00920

DOI=10.3389/fphys.2019.00920

ISSN=1664-042X

ABSTRACT=<p>Intensity regulation during whole-body electromyostimulation (WB-EMS) training is mostly controlled by subjective scales such as CR-10 Borg scale. To determine objective training intensities derived from a maximum as it is used in conventional strength training using the one-repetition-maximum (1-RM), a comparable maximum in WB-EMS is necessary. Therefore, the aim of this study was to examine, if there is an individual maximum intensity tolerance plateau after multiple consecutive EMS application sessions. A total of 52 subjects (24.1 ± 3.2 years; 76.8 ± 11.1 kg; 1.77 ± 0.09 m) participated in the longitudinal, observational study (38 males, 14 females). Each participant carried out four consecutive maximal EMS applications (T1–T4) separated by 1 week. All muscle groups were stimulated successively until their individual maximum and combined to a whole-body stimulation index to carry out a possible statement for the development of the maximum intensity tolerance of the whole body. There was a significant main effect between the measurement times for all participants (<italic>p</italic> &lt; 0.001; 𝜂<sup>2</sup> = 0.39) as well as gender specific for males (<italic>p</italic> = 0.001; 𝜂<sup>2</sup> = 0.18) and females (<italic>p</italic> &lt; 0.001; 𝜂<sup>2</sup> = 0.57). There were no interaction effects of gender × measurement time (<italic>p</italic> = 0.394). The maximum intensity tolerance increased significantly from T1 to T2 (<italic>p</italic> = 0.001) and T2 to T3 (<italic>p</italic> &lt; 0.001). There was no significant difference between T3 and T4 (<italic>p</italic> = 1.0). These results indicate that there is an adjustment of the individual maximum intensity tolerance to a WB-EMS training after three consecutive tests. Therefore, there is a need of several habituation units comparable to the identification of the individual 1-RM in conventional strength training. Further research should focus on an objective intensity-specific regulation of the WB-EMS based on the individual maximum intensity tolerance to characterize different training areas and therefore generate specific adaptations to a WB-EMS training compared to conventional strength training methods.</p>