## 3 Results  
Figure 2 presents a correlation matrix examining the relationships between the eccentric utilization ratio (EUR) and various performance variables. The analysis revealed that EUR was not significantly correlated with SJ (r = \(-0.055\), \(p>0.05\)), CMJ (r = \(0.156\), \(p>0.05\)), COD (r = \(-0.159\), \(p>0.05\)), or CODD% (r = \(-0.238\), \(p>0.05\)). Additionally, EUR showed low and non-significant correlations with sprint performance at all measured intervals: 0-10 m (r = \(0.169\), \(p>0.05\)), 10-20 m (r = \(-0.040\), \(p>0.05\)), 20-30 m (r = \(0.136\), \(p>0.05\)), and 0-30 m (r = \(0.133\), \(p>0.05\)). Figure 3 presents a correlation matrix illustrating the relationships between the eccentric utilization ratio (EUR) and various performance variables in male athletes. The analysis showed that EUR was not significantly correlated with SJ (r = \(-0.411\), \(p>0.05\)), CMJ (r = \(0.077\), \(p>0.05\)), COD (r = \(-0.495\), \(p>0.05\)), or CODD% (r = \(-0.098\), \(p>0.05\)). Regarding sprint performance, the correlations between EUR and 0-10 m (r = \(0.065\), \(p>0.05\)), 10-20 m (r = \(-0.191\), \(p>0.05\)), 20-30 m (r = \(0.099\), \(p>0.05\)), and 0-30 m (r = \(-0.009\), \(p>0.05\)) were also not statistically significant. Figure 2: Correlation analysis results for all participants. (* \(p<0.05\); ** \(p<0.01\); *** \(p<0.001\)). _Color saturation represents the strength of the correlation coefficients (darker hues indicate stronger correlations)._  
Figure 4 presents a correlation matrix illustrating the relationships between the Eccentric, utilization ratio (EUR) and vertical jump, change of direction (COD), change of direction deficit (COD%), and sprint speed in female athletes. The results show that EUR was significantly and positively correlated with CMJ performance (r = 0.587, \(p<0.05\)) and 0-10 m sprint speed (r = 0.516, \(p<0.05\)). These findings suggest that effective use of the eccentric phase may enhance vertical jump performance and contribute to acceleration capacity during the initial phase of sprinting. In particular, the significant positive correlation between EUR and CMJ indicates that efficient elastic energy reutilization during the eccentric phase may be a key factor in improving jump height. In addition, the negative correlations observed between EUR and COD duration (r = \(-\)0.427), as well as COD% (r = \(-\)0.516), suggest a potential role of eccentric phase utilization in change of direction performance. Although the negative correlation with COD% did not reach statistical significance, it may indicate that athletes with higher EUR values are able to change direction more quickly and execute more controlled maneuvers. Specifically, the inverse relationship with COD% implies that athletes who effectively utilize the eccentric phase may experience less angular velocity loss and perform sharper directional changes. On the other hand, EUR was not significantly correlated with sprint performance over longer distances, including 10-20 m (r = 0.122, \(p>0.05\)), 20-30 m (r = 0.493, \(p>0.05\)), and 0-30 m (r = 0.423, \(p>0.05\)). Table 2 presents the results of regression analyses conducted for the overall sample. No statistically significant relationships were found between the eccentric utilization ratio (EUR) and any of the performance variables (\(p>0.05\)). In contrast, the CONMP variable was significantly associated with SJ (\(p=0.001\), R\({}^{2}=0.747\)), CMJ (\(p=0.001\), R\({}^{2}=0.567\)), COD (\(p=0.001\), R\({}^{2}=0.471\)), COD% (\(p=0.001\), R\({}^{2}=0.363\)), and sprint performance at 0-10 m (\(p=0.001\), R\({}^{2}=0.263\)), 10-20 m (\(p=0.001\), R\({}^{2}=0.312\)), 0-20 m (\(p=0.001\), R\({}^{2}=0.328\)), 20-30 m (\(p=0.001\), R\({}^{2}=0.303\)), and 0-30 m (\(p=0.001\), R\({}^{2}=0.438\)). Figure 3: Correlation analysis results for male athletes. (* \(p<0.05\); ** \(p<0.01\); *** \(p<0.001\)).