The effects of whole body electromyostimulation exercise training on physical fitness in middle aged sedentary females

Abstract

The purpose of this study was to determine the effects of whole-body electromyostimulation (WB-EMS) augmented calisthenic training on physique, maximum strength, balance and aerobic endurance and compare said effects to an active control only performing calisthenic exercise. Electromyostimulation (EMS) also known as neuromuscular electrostimulation (NMES) produces a continuous muscle contraction via an electrode placed over a target muscle without any effort from the individual. EMS can be applied locally to a single muscle or in a WB-EMS fashion which allows for the stimulation of 16 different muscular regions simultaneously. Up to 2800 cm2 of muscle mass. EMS has been observed to significantly increase maximum isometric and isokinetic strength. The effects of EMS on body composition and power parameters has varied between different research studies and styles of application. EMS training does not appear to positively affect aerobic fitness in healthy populations though it has in patient populations. The effects of EMS on balance have so far not been explored. In the current study 39 sedentary females aged 35-55 years were allocated to either a control group performing 10-weeks of calisthenic training or an experimental group performing 10-weeks of WB-EMS augmented calisthenic training. Both groups completed a pre-testing (one week prior to the start of the 10-week training) and post-testing (one week following the conclusion of the 10-week training). The main outcomes were physique, determined by evaluating mass (kg), stature (cm) which were used to calculate Body Mass Index (kg/m2), waist and hip girth (cm) which were used to calculate the waist-hip ratio. Strength evaluated by measuring maximum handgrip and leg-and-back strength. Balance assessed by the functional reach (FR) test and aerobic endurance determined by measuring the distance covered with the Cooper-12-minute run/walk test and calculating maximal oxygen uptake (VO2 max) with the use of a regression equation. Following ten-weeks of exercise training significant increases were observed in mass and BMI (kg/m2) in the WB-EMS group and high between-group effect sizes were observed. Significant decreases in waist girth and waist hip ratio were observed in the control with high between-group effect sizes observed for both. Handgrip strength did not change significantly in either group. While leg-and-back strength increased significantly in the WB-EMS group and did not change in the control group. A significant large between-group difference and effect size was also observed in leg-and-back strength. The reach distance achieved in the FR test increased significantly in the WB-EMS group and did not change in the control, however no between-group differences, but a large between-group effect size was observed. Distance covered in the Cooper-12-minute run/walk test and VO2 max did not change significantly in the WB-EMS group but did significantly increase in the control group with medium effect sizes observed. No between group differences were observed with medium between group effect sizes. Findings support that WB-EMS significantly increases strength. However, it is important to carefully place electrodes to stimulate target muscles and any strength increases will not translate to improvements in dynamic strength unless dynamic movements of the same kind are applied during the exercise training sessions. This can be observed in the significant increases in leg-and-back strength as many of the exercise completed during the training session simulated the test action. While neither right nor left handgrip strength changed significantly and none of the exercises performed simulated the test action. WB-EMS does not affect aerobic endurance as shown by the lack of increase in the distance covered and VO2 max. WB-EMS also appears to significantly increase forward reach and dynamic balance, this is curious as no dynamic movements related to the test movement were applied during the exercise sessions. It may be that the primary muscles involved in the test movement were strengthened during the training and this in turn improved the test distance achieved. As there is currently very little information on WB-EMS effect on balance this area should be researched more in the future and the precise mechanisms involved should be investigated.