## 4 Discussion
Additionally, variations in fitness levels [56; 57; 58], age [59; 60], and training backgrounds [61; 62] between the two studies may have significantly affected both physiological responses and participants' perceived exertion, potentially explaining the discrepancies between our findings and those of [PERSON] [53]. The second major objective of our study was to assess whether individuals could effectively regulate their effort based on perceived exertion, as indicated by the RPE scale. Our findings revealed that participants maintained similar cardiovascular parameters (VO2, Rf, HR, power output, etc.) across both the SPV and the IET tests. This reinforces the reliability of the RPE scale as a tool for guiding exercise intensity, even when the pacing strategy differs. Previous studies support these findings, showing that when using RPE to regulate exercise intensity, participants can achieve similar physiological responses compared to when power output is externally controlled [5; 8; 63]. It is important to consider the role of cadence in these findings. During self-paced cycling, individuals tend to favor higher cadence over applying more force, which may optimize energy efficiency and delay the onset of fatigue. Research by [PERSON] and [PERSON] (1993) demonstrated that self-selected cadences are generally higher, which can reduce the overall force required per pedal stroke, allowing for sustained effort over longer periods [64]. In our study, we found that at equal power outputs and physiological parameters (e.g., VO2, HR), the cadence was higher in the SPV test compared to the IET test. This could be explained by the self-regulation aspect of the SPV, where participants may subconsciously choose a higher cadence to maintain a steady perception of effort. Higher cadence at the same power output reduces the force required per pedal stroke, potentially minimizing muscle fatigue and maintaining comfort throughout the test. Research by [PERSON] et al. (1996, 1998) supports this notion, suggesting that higher cadences are preferred in self-paced settings as they help sustain effort by reducing muscular strain [65; 66]. This preference for higher cadence in self-paced exercise aligns with the idea that individuals naturally regulate their effort to optimize both comfort and performance, thus contributing to the similar cardiovascular outcomes observed across different exercise protocols. The findings of this study suggest several practical applications for exercise prescription and training. The demonstrated reliability of the RPE scale in guiding exercise intensity across both self-paced and fixed protocols highlights its utility as a versatile tool in various settings, including clinical and athletic populations. Importantly, the higher cadence observed during self-paced exercise--which likely contributes to the similar cardiovascular outcomes despite different pacing strategies--suggests that encouraging self-regulated exercise may help optimize both comfort and performance. This has significant implications for exercise adherence, as explicit recommendations for self-paced exercise have been shown to improve adherence to exercise programs, particularly among populations less accustomed to structured training [2; 67; 68]. Additionally, recent research by [PERSON] et al. (2024) underscores the importance of self-paced exercise in long-duration endurance events, such as marathons, where maintaining an appropriate pacing strategy can significantly influence performance outcomes [13]. Their study demonstrated that brain activity and RPE can be effectively monitored to optimize pacing and delay the onset of fatigue during a marathon. These findings suggest that similar principles could be applied in various exercise contexts to enhance both performance and adherence. By allowing individuals to tailor their effort based on perceived exertion, self-paced exercise can enhance feelings of autonomy and enjoyment, key factors in promoting long-term adherence to exercise programs and improving overall health outcomes.