AUTHOR=Verch Ronald , Stoll Josephine , Hadzic Miralem , Quarmby Andrew , Völler Heinz 

TITLE=Whole-Body EMS Superimposed Walking and Nordic Walking on a Treadmill—Determination of Exercise Intensity to Conventional Exercise

JOURNAL=Frontiers in Physiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2021.715417

DOI=10.3389/fphys.2021.715417

ISSN=1664-042X

ABSTRACT=<p>Electrical muscle stimulation (EMS) is an increasingly popular training method and has become the focus of research in recent years. New EMS devices offer a wide range of mobile applications for whole-body EMS (WB-EMS) training, e.g., the intensification of dynamic low-intensity endurance exercises through WB-EMS. The present study aimed to determine the differences in exercise intensity between WB-EMS-superimposed and conventional walking (EMS-CW), and CON and WB-EMS-superimposed Nordic walking (WB-EMS-NW) during a treadmill test. Eleven participants (52.0 ± years; 85.9 ± 7.4 kg, 182 ± 6 cm, BMI 25.9 ± 2.2 kg/m<sup>2</sup>) performed a 10 min treadmill test at a given velocity (6.5 km/h) in four different test situations, walking (W) and Nordic walking (NW) in both conventional and WB-EMS superimposed. Oxygen uptake in absolute (VO<sub>2</sub>) and relative to body weight (rel. VO<sub>2</sub>), lactate, and the rate of perceived exertion (RPE) were measured before and after the test. WB-EMS intensity was adjusted individually according to the feedback of the participant. The descriptive statistics were given in mean ± SD. For the statistical analyses, one-factorial ANOVA for repeated measures and two-factorial ANOVA [factors include EMS, W/NW, and factor combination (EMS<sup>*</sup>W/NW)] were performed (α = 0.05). Significant effects were found for EMS and W/NW factors for the outcome variables VO<sub>2</sub> (EMS: <italic>p</italic> = 0.006, <italic>r</italic> = 0.736; W/NW: <italic>p</italic> &lt; 0.001, <italic>r</italic> = 0.870), relative VO<sub>2</sub> (EMS: <italic>p</italic> &lt; 0.001, <italic>r</italic> = 0.850; W/NW: <italic>p</italic> &lt; 0.001, <italic>r</italic> = 0.937), and lactate (EMS: <italic>p</italic> = 0.003, <italic>r</italic> = 0.771; w/NW: <italic>p</italic> = 0.003, <italic>r</italic> = 0.764) and both the factors produced higher results. However, the difference in VO<sub>2</sub> and relative VO<sub>2</sub> is within the range of biological variability of ± 12%. The factor combination EMS<sup>*</sup>W/NW is statistically non-significant for all three variables. WB-EMS resulted in the higher RPE values (<italic>p</italic> = 0.035, <italic>r</italic> = 0.613), RPE differences for W/NW and EMS<sup>*</sup>W/NW were not significant. The current study results indicate that WB-EMS influences the parameters of exercise intensity. The impact on exercise intensity and the clinical relevance of WB-EMS-superimposed walking (WB-EMS-W) exercise is questionable because of the marginal differences in the outcome variables.</p>