ACTive to the peak: Psychological flexibility and the relationship with flow and clutch states

Current research on psychological flexibility (PF) in sport has largely relied on cross-sectional assessments or limited follow-up, which overlooks the inherently dynamic nature of the competitive athletic season. Furthermore, the relationship between PF and optimal mental states associated with enhanced athletic performance, primarily flow and clutch states, remain relatively unexplored. Therefore, this study aimed to longitudinally assess the six processes of psychological flexibility and flow and clutch states across a competitive season. Collegiate soccer players (n = 173) completed online pre-game psychological flexibility and post-game optimal mental states assessments for pre-season, non-conference, conference, and post-season games. Aside from values, the remaining five processes remained stable across the season, providing further support that processes should be specifically targeted via psychological interventions to see improvement. Furthermore, values were a significant predictor of flow states in non-conference games (R²_Adj. = .30), while cognitive defusion significantly predicted clutch states in conference games (R²_Adj. = .67). The remaining processes did not account for a significant amount of variance in flow or clutch states, suggesting that unidimensional psychological flexibility may not be directly related to improving optimal mental states. Practical implications relate to the importance of multidimensional assessment of psychological flexibility, consideration of the relative stability in psychological flexibility, and the finding that psychological flexibility did not directly relate to optimal mental states in the present study.