## 3 Results  
Table 1 presents the statistical characteristics of study participants considered morphological and functional variables.  
Table 2 shows jump height for experimental and control conditions in consecutive measures. Two-way repeated measures ANOVA revealed no significant effects for intervention (F = 0.70; p-eta = 0.03; \(p\) = 0.41) and time (F = 2.30; p-eta = 0.11; \(p\) = 0.08), but the interaction between effects was shown as significant (F = 7.78; p-eta = 0.30; \(p\) < 0.01). Detailed comparison with the Bonferroni post hoc test showed that the consecutive measures of jump height in the experimental condition were higher than the baseline in the 3 rd minute \(p\) = 0.02; ES = 0.30 in the 6 th \(p\) < 0.01; ES = 0.39, and in the 9 th \(p\) < 0.01, ES = 0.32 (Figure 2).  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Variable** & **Mean \(\pm\) SD (95\% CD)** \\ \hline Body height (cm) & 183.9 \(\pm\) 25.3 (165.7–202) \\ \hline Body weight (kg) & 74.2 \(\pm\) 12.1 (65.6–82.8) \\ \hline BMI (kg/m\({}^{2}\)) & 22.4 \(\pm\) 4 (19.6–25.2) \\ \hline Back squat 1 repetition max (kg) & 117.4 \(\pm\) 31.4 (94.9–139.9) \\ \hline Relative strength (1 RM/body weight; kg) & 156.2 \(\pm\) 26.7 (137.1–175.2) \\ \hline Gym experience (years) & 3.5 \(\pm\) 1.8 (2.2–4.8) \\ \hline Training volume/week (minute) & 321 \(\pm\) 118.4 (236.3–405.7) \\ \hline Countermovement jump (cm) & 35.3 \(\pm\) 6.3 (30.8–39.8) \\ \hline Eccentric utilization ratio (cm) & 1.0 \(\pm\) 0.1 (0.9–1.1) \\ \hline Limb symmetry index (\%) & 97.1 \(\pm\) 8 (91.4–102.8) \\ \hline \hline \end{tabular}
\end{table}
Table 1: Descriptive statistics of study participants.  
In the next step of the analysis, time to peak performance (best results appearance) was considered. Two individuals' peak performance appeared in the 3 rd minute, five in the 6 th minute, and two in the 9 th minute. One participant did not achieve any improvement. However, the chi-square analysis showed that the observed frequency was insignificant (\(\chi^{2}=3.6\); \(p=0.3\)).  
Based on the typical error calculation, the cut-off value for distinguishing responders (RS) and non-responders (nRS) was 3.29. Based on this, five individuals were indicated as RS and five as nRS. Then, a Student \(t\)-test for independent samples was performed (Table 3) to compare individuals' characteristics, considering morphological and functional factors. The results showed no difference was statistically significant (\(p>0.05\)), but effect size values suggested that some values could be meaningful. Indeed, RS relative strength was higher than nRS with large ES (ES > 0.80). Further, BMI and asymmetry in the legs, due to jump height ability, were higher in nRS with medium ES (0.30 \(<\) ES \(<\) 0.80). Also, medium ES due to higher values in RS was observed in CMJ and SJ baseline and gym experience. The ES was considered trivial for the rest of the variables (ES \(<\) 0.30).  
\begin{table}
\begin{tabular}{c c c} \hline \multirow{2}{*}{**Time (min)**} & **Experimental** & **Control** \\ \cline{2-3}  & \multicolumn{2}{c}{**Mean \(\pm\) SD (95\% CI)**} \\ \hline Baseline (cm) & 35.7 \(\pm\) 6.1 (31.3–40.1) & 35.5 \(\pm\) 6.1 (31.1–39.8) \\ \hline
3 rd (cm) & 37.8 \(\pm\) 7.8 (32.2–43.4) & 35.1 \(\pm\) 6 (30.8–39.4) \\ \hline
6 th (cm) & 38.4 \(\pm\) 7.4 (33.1–43.6) & 34.6 \(\pm\) 6.5 (29.9–39.3) \\ \hline
9 th (cm) & 38.1 \(\pm\) 8.6 (32–44.3) & 34.7 \(\pm\) 6 (30.4–38.9) \\ \hline \end{tabular}
\end{table}
Table 2: Jump height due to the time of measurement for the experimental and control conditions.  
Figure 2: Jump height results over time according to conditions (experimental and control). Points represent means. Bars represent 95% confidence intervals.