Background/Objective: There is little research on the effectiveness of new approaches to psychology, including mindfulness-acceptance-commitment, especially in team disciplines. Therefore, this study compared mindfulness-acceptance and commitment-based approaches to rumination, cognitive flexibility, and sports performance of elite beach soccer players during a two-month follow-up. Methods: The research design consisted of a randomized controlled trial (RCT), with follow-up. Thus, 34 players of the premier league of beach soccer were randomly divided into intervention and control groups based on mindfulness acceptance and commitment. The experimental group exercises consisted of one session per week for 7 weeks and daily homework. Participants filled out the questionnaires of the Ruminative Response Scale, Cognitive Flexibility Inventory, and Sports Performance Questionnaire before, after, and at two months of follow-up of the intervention. Results: Multivariate Analysis of Variance (MANOVA) and Analysis of Variance (ANOVA) with repeated measures were used to evaluate the changes over time and compare the scores of the subjects of the two groups. The results showed a significant difference in mindfulness-acceptance and commitment intervention in the experimental group on pre- vs. post-test and pre-test vs. follow-up scores of research variables. Also, a comparison of groups using independent T-test analysis showed a significant effect of mindfulness-acceptance and commitment exercises on research variables in the experimental group in the post-test and follow-up stages. Conclusion: Findings suggest that mindfulness, commitment, and acceptance exercises can be used as a new method to reduce rumination and increase cognitive flexibility and sports performance of elite beach soccer players.
Sabzevari et al. (2023) studied this question.