Effects of an Eight-Week Superimposed Submaximal Dynamic Whole-Body Electromyostimulation Training on Strength and Power Parameters of the Leg Muscles: A Randomized Controlled Intervention Study

Abstract

The purpose of this study was to assess the effects of dynamic superimposed submaximal whole-body electromyostimulation (WB-EMS) training on maximal strength and power parameters of the leg muscles compared with a similar dynamic training without WB-EMS. Eighteen male sport students were randomly assigned either to a WB-EMS intervention (INT; n = 9; age: 28.8 (SD: 3.0) years; body mass: 80.2 (6.6) kg; strength training experience: 4.6 (2.8) years) or a traditional strength training group (CON; n = 9; age: 22.8 (2.5) years; body mass: 77.6 (9.0) kg; strength training experience: 4.5 (2.9) years). Both training intervention programs were performed twice a week over a period of 8 weeks with the only difference that INT performed all dynamic exercises (e.g., split squats, glute-ham raises, jumps, and tappings) with superimposed WB-EMS. WB-EMS intensity was adjusted to 70% of the individual maximal tolerable pain to ensure dynamic movement. Before (PRE), after (POST) and 2 weeks after the intervention (FU), performance indices were assessed by maximal strength (Fmax) and maximal power (Pmax) testing on the leg extension (LE), leg curl (LC), and leg press (LP) machine as primary endpoints. Additionally, vertical and horizontal jumps and 30 m sprint tests were conducted as secondary endpoints at PRE, POST and FU testing. Significant time effects were observed for strength and power parameters on LE and LC (LE Fmax +5.0%; LC Pmax +13.5%). A significant time × group interaction effect was merely observed for Fmax on the LE where follow-up post hoc testing showed significantly higher improvements in the INT group from PRE to POST and PRE to FU (INT: +7.7%, p < 0.01; CON: +2.1%). These findings indicate that the combination of dynamic exercises and superimposed submaximal WB-EMS seems to be effective in order to improve leg strength and power. However, in young healthy adults the effects of superimposed WB-EMS were similar to the effects of dynamic resistance training without EMS, with the only exception of a significantly greater increase in leg extension Fmax in the WB-EMS group.

Effects of Two Modalities of Whole-body Electrostimulation Programs and Resistance Circuit Training on Strength and Power

“…These results are in agreement with those reported by Kemmler et al [14] and Micke et al [7], confirming the possible alternative or contributive use of the WB-EMS methods to the efficient training of strength and power. In particular, with respect to the study by Micke et al (2018), which focused on the strength and power parameters of the leg muscles, our study added new findings investigating the effects of WB-EMS programs on strength and power parameters of upper and lower limbs using force-velocity curves as suggested by Bosco and Komi [20], Bosco [21], and Zatsiorsky and Kraemer [22]. In particular, ▶ Figs 2-5 indicate the right shift of the entire curves, after the three treatments, demonstrating that both the area of force and that of velocity have increased in a similar way, thus causing harmonics adaptations in all the expressions of muscular force we considered [23].…”

“…Electrical muscle stimulation (EMS) consists of local application of an electric current to elicit a muscle contraction [1]; in sports training, the most commonly used technique is percutaneous electrical stimulation, where the electrostimulation is applied to the muscular belly [2]. Several studies performed both in the medical and sports fields have extensively analyzed the principles and the parameters of the EMS [mainly considering the intensity of the electrical stimulus (Amp), the frequency (Hz), and the width of the impulse] and the physiological adaptations to the EMS training [3][4][5][6][7][8][9][10][11][12]27]. Certainly, fewer studies have taken into account whole-body electromyostimulation (WB-EMS), a training method associated with a voluntary pre-contraction both isometric or dynamic [10,13].…”

“…Recently, the study by Micke et al [7] has shown that a WB-EMS program provides similar improvements, compared to a traditional training program, in terms of maximal isometric strength (F max ) and maximal isoinertial power (P max ) for the leg muscles, measured through the leg extension (LE), leg curl (LC), and leg press (LP) machines, of jumping performances, measured by the means of squat jump (SJ), counter movement jump (CMJ), drop jump (DJ) and standing long jump (SLJ), of sprinting abilities measured through linear (30 m) and shuttle sprinting (3 x10 m).…”

Impact of Whole Body Electromyostimulation on Velocity, Power and Body Composition in Postmenopausal Women: A Randomized Controlled Trial

“…Wirtz et al [72] found improvements in the leg flexors in an isoinertial power test with a leg curl machine. The same happened in the leg curl power strength in Wirtz et al [85]. Their studies were carried out with young trained males, but they agreed with the results of the present study in the successfulness of the WB-EMS enhancing the power in an isolated way.…”

Effects of Whole Body Electromyostimulation on Physical Fitness and Health in Postmenopausal Women: A Study Protocol for a Randomized Controlled Trial

“…Other studies designed interventions whose control group carried out exercises of the same nature as the experimental group, but their training did not match the volume and frequency of training loads (58,60,114,115). The protocol of the present study intends to carry out an experimental phase in which the interventions of both groups are completely comparable in terms of type of movements and training volume (116)(117)(118). It will allow identifying precisely the isolated effect of the WB-EMS.…”