Heart Rate Variability Dynamics in Padel Players: Set-by-Set and Rest Period Changes in Relation to Match Outcome

<b>Objective</b>: The aim of this study was to analyse the evolution of heart rate variability (HRV) during official competition in high-level amateur padel players according to match outcome. <b>Methods</b>: HRV was measured in 44 individual recordings obtained across 11 matches involving 12 padel players. Measurements were taken before the match (PRE), during three sets (S1, S2 and S3) and during the two rest periods between sets (R1 and R2). Time-domain variables analysed included mean R-R interval (Mean RR), standard deviation of normalised R-R intervals (SDNN), root mean square of successive differences (RMSSD), natural logarithm of RMSSD (LnRMSSD) and standard deviation of heart rate (STD HR), while nonlinear variables included the transverse (SD1) and longitudinal (SD2) axes of the Poincare plot, stress score (SS) and the sympathetic-parasympathetic ratio (SNS/PNS ratio). <b>Results</b>: Significant fluctuations in HRV were observed throughout the match. Players who won exhibited significantly higher values of Mean RR, SDNN, RMSSD, LnRMSSD, SD1 and SD2 during S1 (<i>p</i> < 0.05), and higher Mean RR, RMSSD, LnRMSSD and SD1 during R1 (<i>p</i> < 0.01). These differences diminished as the match progressed, disappearing in the later phases (S3, R2). Temporal analysis revealed that both groups showed parasympathetic recovery during the rest periods. <b>Conclusions</b>: This study provides novel evidence on the temporal dynamics of autonomic regulation in padel, showing that match outcome is associated with differences in cardiovascular regulation during the initial phases of competition. These findings support the usefulness of HRV monitoring for performance management in real competition settings.