Indirect associations through emotion suppression between subjective sleep quality, habitual sleep efficiency, daytime dysfunction, and mental toughness in combat sports athletes: a cross-sectional study

Background Reduced sleep quality is associated with impaired emotional functioning. This study examined whether emotion suppression was involved in cross-sectional indirect associations between three sleep-related components – subjective sleep quality, habitual sleep efficiency, and daytime dysfunction – and mental toughness in combat sports athletes. Methods Ninety male combat sports athletes – aged between 18 and 34 years ( M = 25.26) – completed the Pittsburgh Sleep Quality Index (PSQI), the Courtauld Emotional Control Scale (CECS), and the Sport Mental Toughness Questionnaire (SMTQ). To examine cross-sectional associations through emotion suppression between the three analyzed sleep components and athletes’ mental toughness, indirect association analyses were conducted. Results Significant cross-sectional indirect associations through depressive emotion suppression were observed between each of the three sleep components – subjective sleep quality, habitual sleep efficiency, and daytime dysfunction – and mental toughness. No statistically significant indirect associations through either anger or anxiety were observed. Conclusion The findings suggest that depressive emotion suppression may be relevant to the relationship between sleep-related functioning and mental toughness in combat sports athletes. This highlights the potential importance of considering emotional functioning alongside sleep-related factors when examining mental toughness in this population.