## 4 Discussion  
Based on the results of this study, the decrease in the MDF of the RFM and TAM was significantly lesser in the PTG after six weeks of training compared to that of the CG, and there was significant improvement in both the BA performance and maximum vertical jump height in the PTG. From the results, the MDF increased in both the RFM and TAM as the number of rounds increased. In other words, under the effects of the exercise load in this study, the contraction ability of the muscles was reduced, and the characteristics of the power spectrum were altered. Among the MDF data for the four muscles, the TAM showed the greatest improvement. However, the MDF of these four muscles still decreased as the number of rounds in the blocking test increased. The amount of muscle recruitment in various parts of the legs when jumping was studied [22], and the results showed that the principal muscle groups recruited when performing squat jumps are the TAM \(>\) RFM \(>\) GM \begin{table}
\begin{tabular}{l c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**PTG**} & \multicolumn{2}{c}{**CG**} & \multicolumn{2}{c}{**Interaction**} & \multicolumn{1}{c}{**Main**} & \multicolumn{1}{c}{**Post-hoc**} \\ \hline  & T1 & T2 & T3 & T1 & T2 & T3 & **Effect** & **Effects** & **Test** \\ \hline Pre-test & 2.04 \(\pm\) 0.16 & 2.08 \(\pm\) 0.13 & 2.11 \(\pm\) 0.13 & 2.07 \(\pm\) 0.15 & 2.08 \(\pm\) 0.16 & 2.11 \(\pm\) 0.13 & \multirow{2}{*}{0.618} & \multirow{2}{*}{58.287 **} & \multirow{2}{*}{CG \(>\) PTG} \\ Post-test & 1.93 \(\pm\) 0.12 & 1.95 \(\pm\) 0.12 & 1.96 \(\pm\) 0.11 & 2.06 \(\pm\) 0.16 & 2.08 \(\pm\) 0.16 & 2.09 \(\pm\) 0.18 & & \\ \hline \hline \end{tabular}  
* PTG: pyometric training group; CG: control group. The table indicates significant change (post–pre) when using the pre-test score as a covariate: **\(p<\) 0.01.  
\end{table} 
Table 4: Values are the mean \(\pm\) standard deviation. Data are reported for the blocking agility (BA) test. The unit of BA is second (s). \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **PTG** & **CG** & **F-value** & **Post-hoc Test** \\ \hline Pre-test & 67.04 \(\pm\) 3.83 & 66.86 \(\pm\) 4.06 & \multirow{2}{*}{26.862 **} & \multirow{2}{*}{PTG \(>\) CG} \\ Post-test & 69.27 \(\pm\) 3.87 & 66.79 \(\pm\) 3.76 & & \\ \hline \hline \end{tabular}  
* PTG: pyometric training group; CG: control group. The table indicates significant change (post–pre) with the pre-test score as a covariate: **\(p<\) 0.01.  
\end{table} 
Table 5: Values are the mean \(\pm\) standard deviation. Data are reported for the maximum vertical jump height. Units in centimeters (cm). BFM; that is, the TAM and RFM are the principal muscle groups used when jumping. In the results of the continuous jump blocking test conducted on the study participants in the present study, the decrease in MDF in the legs improved in the PTG after a six-week interventional training; this result is consistent with that of previous studies [16]. The report [16] indicated that the pyometric training (PT) increased central fatigue significantly by about 15-20%, but significantly decreased peripheral (muscle) fatigue during the 2-min MVC by about 10% in the quadriceps femoris. In this study, the MDF of the RMF and TAM of the PTG and CG decreased by similar percentages in the pre-test. However, the MDF of the PTG was significantly higher than that of the CG in the second round (by 2.13% and 4.14% for the PTG) and the third round (by 4.75% and 7.71% for the PTG). In other words, pyometric training can delay the decrease in MDF, but it cannot alter the development of fatigue. The ANCOVA results show that the BA of the PTG improved significantly after six weeks of training. Although not reflected as statistically significant, the BA increased as the number of rounds increased. These results show that the change occurred more gradually in the PTG. With respect to the average percentage of improvement, the PTG improved by 6.26% after six weeks of interventional training, whereas the CG improved by only 0.48%.