## 4 Discussion  
To date, the effects of PAPE on explosive movements such as jumping, sprinting, and agility have been frequently investigated. However, research exploring its potential impact on postural performance, especially in female volleyball players, remains scarce. To address this gap, the present study explored the effects of acute pyometric conditioning activity on unilateral CMJ performance and postural sway in national-level female volleyball players, focusing on different recovery intervals. As mentioned earlier, while moderate-to-high intensity loads are crucial for optimizing the PAPE effect [8], a conditioning activity that induces less fatigue could also be a viable  
Figure 3: Significant differences in R6 compared with baseline and other recovery intervals in dominant and non-dominant leg postural sway performances. strategy, considering individual responses to conditioning stimuli. However, identifying the optimal PAPE protocol remains challenging, emphasizing the significance of the study sample and the fatigue-potentiation interaction [46]. In light of these considerations, this study used an acute pyometric exercise (i.e., RCMJ-30) as the PAPE protocol [47]. The test-retest reliability results for RCMJ-30 parameters, such as maximum and mean jump height, ranged from moderate-to-good under certain conditions, suggesting that the RCMJ-30 test can be a reliable and effective conditioning activity for inducing PAPE when specific parameters are met. Research on PAP/PAPE generally indicates that a recovery period of 0-15 min may be sufficient for optimizing explosive movement performance [14; 48; 49; 50; 51], though the optimal recovery interval remains inconsistent. Our findings suggest that R8 was more effective in enhancing unilateral CMJ performance (i.e., jump height and flight time) following the PAPE protocol (Table 2). These findings suggest that the changes observed in both the dominant and non-dominant legs were consistent, demonstrating symmetry along the lower-extremity axis. Additionally, this improvement in unilateral CMJ, which reflects lower-extremity explosive power, may be explained by the impact of the conditioning activity mechanism, including the phosphorylation of myosin light chains and the acceleration of force development interactions [2]. Studies utilizing pyometric stimuli as a conditioning activity within the PAPE framework have shown that CMJ measurements at 1, 3, and 5 min recovery intervals result in greater jump height and peak power compared with baseline [19]. Similarly, [PERSON] et al. [52] reported that an 8 min recovery interval was the most effective for enhancing CMJ performance. In contrast, a resistance-based stimulus (3 \(\times\) 3 squat at 87% 1 RM) has also been shown to optimize CMJ performance with an 8 min recovery interval [53]. Regarding physiological recovery, 2 min of recovery allows for approximately 67% replenishment of phosphocreatine stores, while 4 min enables about 84% recovery [54], and even close to 100% after 10 min of rest [55]. Thus, the R8 interval in our study was consistent with expected outcomes, considering the restoration of energy systems. Despite the overall consistency in performance responses among participants, some individual variation is evident. However, our data indicate that single-leg CMJ values tended to increase for most participants (Figure 2), further supporting the statistical significance observed in the R8 condition. [PERSON] et al. [56] found that an isometric stimulus yielded greater improvements in vertical jump performance when athletes were allowed to select their own recovery interval, compared with other protocols that fixed recovery intervals. This approach is grounded in the belief that self-determined recovery intervals may enhance performance outcomes [57]. Although both the existing literature and our findings mostly focus on specific recovery intervals (up to 15 min) in relation to jump performance, the choice of PAPE protocol and recovery period can significantly influence jump performance outcomes.