Abstract
BACKGROUND: Coach athlete relational quality plays a pivotal role in adolescent athlete development, yet few studies have examined its association with mental toughness through the lens of coach gender in non-Western contexts. This study explored whether relational quality statistically mediates the link between coach gender and mental toughness in adolescent female basketball players in Turkey, using a sequential explanatory mixed-methods design grounded in Self-Determination Theory and Social Role Theory. METHODS: A total of 366 female adolescent basketball players (aged 12-18) from 22 teams completed validated Turkish versions of the Sports Mental Toughness Questionnaire-Youth (SMTQ-Y) and the Coach-Athlete Relationship Questionnaire-Child (CART-Q-C). Multi-group confirmatory factor analysis confirmed scalar measurement invariance across coach gender and age groups. Quantitative analyses employed Ordinary Least Squares (OLS) regression with cluster-robust standard errors to account for team-level nesting. A subsample of 24 athletes participated in semi-structured interviews, thematically analysed to contextualize statistical patterns. RESULTS: Female-coached athletes reported significantly higher mental toughness and relational quality (Cohen's d = 0.59-0.64). Regression analyses revealed that relational quality was the strongest predictor of mental toughness (β = 0.51, p < .001). Mediation analysis confirmed that relational quality statistically mediated the association between coach gender and mental toughness (indirect effect B = 0.216, 95% CI [0.121, 0.311]). Qualitative findings identified three mechanisms, relational empowerment, gender-congruent role modelling, and emotional atonement, that helped explain this mediation. CONCLUSION: The findings suggest that female coaches are statistically associated with enhanced relational environments, which in turn appear to co-occur with greater mental toughness in adolescent female athletes. These patterns underscore the need for culturally sensitive coach education programs that emphasize relational competence and support female leadership in youth sport systems.