Acute psychological responses to official match outcomes in male youth volleyball: an observational repeated-measures study within a single national-level team.

Background: Official match outcomes may be associated with acute psychological responses in youth athletes, particularly in team sports characterized by high emotional and interpersonal demands. Objective: To examine acute psychological responses in male youth volleyball athletes during official matches in a national-level competition, focusing on associations with match outcome (win vs. loss), playing status (starter vs. substitute), and assessment moment (pre- vs. post-match). Methods: Fourteen male athletes (mean age 16.5 ± 0.82 years) from a single Brazilian national-level team were followed across 20 official matches (14 wins and 6 losses). Psychological responses were assessed before and/or after matches using validated instruments: State Anxiety (STAI-IDATE), Brunel Mood Scale (BRUMS), Feeling Scale, Physical Activity Enjoyment Scale (PACES), and Total Quality Recovery (TQR). Generalized estimating equations (GEE) were used with an independent working correlation structure and robust (sandwich) standard errors. Fixed effects included match outcome, playing status, assessment moment, and their interactions. Candidate marginal models were compared via Independence Model Criterion under a parsimonious strategy suitable for small samples. Results: Losses were associated with increased post-match state anxiety, tension, depression, anger, and confusion, whereas wins were generally associated with stability or more favorable responses in these dimensions. Affective valence also showed an outcome×moment interaction, declining after losses but remaining relatively stable after wins. Vigor demonstrated a three-way interaction between playing status, outcome, and moment, with substitutes showing a more pronounced decline after losses. Fatigue showed main effects of playing status, match outcome, and moment. Enjoyment was higher in wins than losses and higher in starters than substitutes. Perceived recovery showed a playing status×outcome interaction, with starters reporting higher pre-match recovery before matches that resulted in wins. Conclusion: In this single-team observational sample, acute psychological responses appeared to vary according to match outcome, playing status, and assessment moment. These findings should be interpreted as exploratory associations and may support the practical value of psychological monitoring in youth competitive volleyball.