Table 2. Descriptives, ANOVA and multiple comparisons of all parameters. Values are presented as means (± SD). Outcome parameter Group PRE POST Delta PRE-POST % Delta PRE-POST Univariate ANOVA a Multiple comparison (LSD) b p ηp² Groups p Jump tests CMJ [cm] CON T20 T85 24.6 ± 6.2 25.4 ± 9.0 26.5 ± 8.1 24.5 ± 5.7 27.8 ± 7.6 28.4 ± 7.3 - 0.3 ± 2.3 2.4 ± 2.2 1.9 ± 2.3 - 0.4 % + 9.5 % + 9.5 % 0.007** 0.191 CON vs. T20 CON vs. T85 T20 vs. T85 0.002** 0.013* 0.456 SJ [cm] CON T20 T85 23.2 ± 6.0 23.9 ± 8.5 24.3 ± 7.0 23.5 ± 6.0 26.2 ± 7.3 26.8 ± 6.4 0.3 ± 1.4 2.4 ± 2.2 2.5 ± 2.4 + 1.3 % + 9.6 % + 10.3 % 0.022* 0.150 CON vs. T20 CON vs. T85 T20 vs. T85 0.018* 0.010* 0.832 DJ [Index] CON T20 T85 87.4 ± 34.1 97.4 ± 37.2 101.5 ± 33.9 91.1 ± 32.3 110.1 ± 35.4 115.8 ± 32.7 0.1 ± 19.2 12.7 ± 18.7 14.3 ± 18.5 + 4.2 % + 13.0 % + 14.1 % 0.104 0.094 Sprint tests 5 m [s] CON T20 T85 1.15 ± 0.09 1.15 ± 0.09 1.11 ± 0.11 1.15 ± 0.05 1.13 ± 0.08 1.11 ± 0.08 - 0.01 ± 0.08 - 0.02 ± 0.06 0.00 ± 0.09 ± 0.0 % - 1.7 % ± 0.0 % 0.744 0.012 10 m [s] CON T20 T85 2.07 ± 0.16 2.03 ± 0.17 1.94 ± 0.17 2.04 ± 0.10 2.01 ± 0.17 1.94 ± 0.14 - 0.04 ± 0.09 - 0.02 ± 0.08 0.00 ± 0.12 - 1.5 % - 1.0 % ± 0.0 % 0.543 0.026 30 m [s] CON T20 T85 5.35 ± 0.52 5.15 ± 0.59 4,88 ± 0.47 5.34 ± 0.44 5.06 ± 0.57 4.87 ± 0.44 - 0.05 ± 0.18 - 0.08 ± 0.21 - 0.01 ± 0.16 - 0.2 % - 1.8 % - 0.2 % 0.511 0.028 Strength tests Trunk Flexion [kg] CON T20 T85 43.3 ± 18.6 49.1 ± 17.2 53.3 ± 20.1 45.7 ± 20.1 56.4 ± 19.3 62.4 ± 24.6 2.0 ± 6.3 7.1 ± 5.9 9.1 ± 7.9 + 5.5 % + 14.9 % + 17.1 % 0.020* 0.150 CON vs. T20 CON vs. T85 T20 vs. T85 0.042* 0.006** 0.388 Trunk Extension [kg] CON T20 T85 58.5 ± 20.6 60.3 ± 17.9 68.2 ± 23.0 62.7 ± 20.5 72.9 ± 18.1 77.9 ± 25.7 3.9 ± 5.5 12.6 ± 9.1 9.6 ± 8.4 + 7.1 % + 20.9 % + 14.2 % 0.013* 0.162 CON vs. T20 CON vs. T85 T20 vs. T85 0.003** 0.048* 0.184 a Results of the univariate ANOVA of the Delta values; b Group comparisons: control group (CON), 20 Hz training group (T20), 85 Hz training group (T85); * p < 0.05, **p < 0.0.1