Effects of Four Weeks of Static vs. Dynamic Bodyweight Exercises with Whole-Body Electromyostimulation on Jump and Strength Performance: A Two-Armed, Randomized, Controlled Trial

The combination of strength training with complementary wholebody electromyostimulation (WB-EMS) and plyometric exercises has been shown to increase strength and jumping performance in athletes. In elite sport, however, the mesocycles of training are often organized according to block periodization. Furthermore, WB-EMS is often applied onto static strength exercises, which may hamper the transfer into more sport-specific tasks. Thus, this study aimed at investigating whether four weeks of strength training with complementary dynamic vs. static WBEMS followed by a four-week block of plyometric training increases maximal strength and jumping performance. A total of n = 26 (13 female/13 male) trained adults (20.8 +/- 2.2 years, 69.5 +/- 9.5kg, 9.7 +/- 6.1h of training/w) were randomly assigned to a static (STA) or volume-, load- and work-to-rest-ratio-matched dynamic training group (DYN). Before (PRE), after four weeks (three times weekly) of WB-EMS training (MID) and a subsequent fourweek block (twice weekly) of plyometric training (POST), maximal voluntary contraction (MVC) at leg extension (LE), leg curl (LC) and leg press machines (LP) and jumping performance (SJ, Squat Jump; CMJ, counter-movement-jump; DJ, drop-jump) were assessed. Furthermore, perceived effort (RPE) was rated for each set and subsequently averaged for each session. MVC at LP notably increased between PRE and POST in both STA (2335 +/- 539 vs. 2653 +/- 659N, standardized mean difference [SMD] = 0.528) and DYN (2483 +/- 714N vs. 2885 +/- 843N, SMD = 0.515). Reactive strength index of DJ showed significant differences between STA and DYN at MID (162.2 +/- 26.4 vs. 123.1 +/- 26.5 cm.s1, p = 0.002, SMD = 1.478) and POST (166.1 +/- 28.0 vs. 136.2 +/- 31.7 cm.s-1, p = 0.02, SMD = 0.997). Furthermore, there was a significant effect for RPE, with STA rating perceived effort higher than DYN (6.76 +/- 0.32 vs. 6.33 +/- 0.47 a.u., p = 0.013, SMD = 1.058). When employing a training block of high-density WB-EMS both static and dynamic exercises lead to similar adaptations.