# Effects of Plyometric and Short Sprint with Change-of-Direction Training in Male U17 Soccer Players
## 4 Discussion  
Here, we aimed to assess the effectiveness of 8 weeks of combined PSSCoD training for improving athletic performance in elite youth soccer players. The data suggest that replacing some aspects of habitual training with combined PSSCoD training improves vertical and horizontal jump performance, sprinting, change-of-direction ability, RSA, and balance.  
\begin{table}
\begin{tabular}{l c c c c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Experimental (n = 18)**} & \multicolumn{2}{c}{**Paired \(t\)-Test**} & \multicolumn{2}{c}{**Control (n = 16)**} & \multicolumn{2}{c}{**Paired \(t\)-Test**} & \multicolumn{2}{c}{**ANOVA (Group \(\times\) Time)**} \\  & **Pre** & **Post** & **\% \(\Delta\)** & **\(p\)-Value** & **ES** & **Pre** & **Post** & **\% \(\Delta\)** & **\(p\)-Value** & **ES** & **\(p\)-Value** & **ES** \\ \hline \hline \multicolumn{10}{c}{Vertical jump} \\ SI (cm) & \(26.7\pm 3.8\) & \(31.8\pm 4.4\) & \(19.1\pm 2.4\) & \(0.001\) & \(1.23\) & \(27.1\pm 3.5\) & \(28.2\pm 3.5\) & \(4.1\pm 1.8\) & \(0.001\) & \(0.26\) & \(0.037\) & \(0.53\) (medium) \\ CMJ (cm) & \(28.9\pm 3.9\) & \(34.9\pm 3.5\) & \(20.9\pm 3.5\) & \(0.001\) & \(1.54\) & \(29.2\pm 3.0\) & \(30.7\pm 3.3\) & \(5.2\pm 2.1\) & \(0.001\) & \(0.30\) & \(0.014\) & \(0.63\) (medium) \\ \hline \multicolumn{10}{c}{Horizontal jump} \\ SI (m) & \(1.8\pm 0.2\) & \(2.0\pm 0.2\) & \(13.3\pm 1.9\) & \(0.001\) & \(1.11\) & \(1.8\pm 0.2\) & \(1.8\pm 0.2\) & \(2.7\pm 1.9\) & \(0.001\) & \(0.10\) & \(0.053\) & \(0.49\) (small) \\ \hline \multicolumn{10}{c}{Sprint} \\
5 m (s) & \(1.2\pm 0.1\) & \(1.1\pm 0.1\) & \(-10.6\pm 0.0\) & \(0.001\) & \(1.62\) & \(1.2\pm 0.1\) & \(1.7\pm 0.1\) & \(-2.4\pm 1.0\) & \(0.001\) & \(0.08\) & \(0.042\) & \(0.52\) (medium) \\
20 m (s) & \(3.4\pm 0.1\) & \(3.1\pm 0.1\) & \(-8.2\pm 1.3\) & \(0.001\) & \(2.17\) & \(3.4\pm 0.2\) & \(3.3\pm 0.2\) & \(-2.1\pm 0.6\) & \(0.001\) & \(0.06\) & \(0.013\) & \(0.64\) (medium) \\ \hline \multicolumn{10}{c}{Change-of-direction Performance} \\  & \(6.4\pm 0.3\) & \(5.8\pm 0.25\) & \(-9.4\pm 0.7\) & \(0.001\) & \(2.38\) & \(6.4\pm 0.3\) & \(6.2\pm 0.2\) & \(-2.1\pm 0.8\) & \(0.001\) & \(0.11\) & \(0.003\) & \(0.78\) (medium) \\ \hline \multicolumn{10}{c}{Repeated Shuttle Sprint Ability parameters} \\ Fastest time (s) & \(7.9\pm 0.4\) & \(7.3\pm 0.4\) & \(-7.5\pm 0.7\) & \(0.001\) & \(1.62\) & \(7.8\pm 0.4\) & \(7.7\pm 0.4\) & \(-1.3\pm 0.2\) & \(0.001\) & \(0.26\) & \(0.007\) & \(0.70\) (medium) \\ Mean time (s) & \(8.1\pm 0.4\) & \(7.5\pm 0.4\) & \(-7.8\pm 0.9\) & \(0.001\) & \(1.82\) & \(8.0\pm 0.4\) & \(7.9\pm 0.37\) & \(-1.4\pm 0.7\) & \(0.001\) & \(0.30\) & \(0.004\) & \(0.74\) (medium) \\ Total time (s) & \(2.6\pm 1.5\) & \(2.3\pm 1.2\) & \(-2.3\pm 40.2\) & \(0.216\) & \(0.20\) & \(2.2\pm 0.8\) & \(2.2\pm 0.9\) & \(-0.0\pm 30.6\) & \(0.716\) & \(0.30\) & \(0.705\) & \(0.09\) (small) \\ \hline \multicolumn{10}{c}{Stork balance test} \\ Right leg (s) & \(12.4\pm 7.5\) & \(22.7\pm 13.5\) & \(82.9\pm 3.0\) & \(0.001\) & \(0.93\) & \(12.8\pm 8.2\) & \(13.6\pm 8.7\) & \(6.8\pm 3.7\) & \(0.001\) & \(0.11\) & \(0.054\) & \(0.49\) (small) \\ Left leg (s) & \(10.7\pm 6.2\) & \(18.2\pm 10.5\) & \(70.7\pm 3.8\) & \(0.001\) & \(0.87\) & \(10.9\pm 3.9\) & \(11.9\pm 4.7\) & \(9.1\pm 2.8\) & \(0.001\) & \(0.15\) & \(0.053\) & \(0.49\) (small) \\ \hline \multicolumn{10}{c}{Note: A 2-way analysis of variance (group \(\times\) time) assessed the statistical significance of training-related effects. SJ—squat jump; CMJ—counter movement jump; SIJ—standing long jump.} \\ \end{tabular}
\end{table}
Table 4: Test performances in experimental and control groups before and after 8-week intervention.