Mindfulness-Acceptance-Commitment Intervention Effects on Athletic Performance, Passion, and Psychological Well-being in Competitive Tennis Players: A Randomized Controlled Trial

While traditional psychological skills training focuses on cognitive control, mindfulness-based approaches emphasize acceptance and present-moment awareness. The Mindfulness-Acceptance-Commitment (MAC) protocol shows promise for enhancing athletic performance; however, limited research has examined its effects on passion and well-being in tennis players. Forty-four competitive male tennis players (M age = 18.1 ± 1.1 years) were randomly assigned to either a MAC intervention group (n = 22) or a passive control group (n = 22). The MAC protocol consisted of seven weekly 45-minute sessions focusing on mindfulness, acceptance, and values-driven behavior. Primary outcomes included tennis serve performance assessed by certified coaches using a standardized 16-serve protocol. Secondary outcomes included mindfulness skills (Mindful Attention Awareness Scale), subjective well-being (Positive and Negative Affect Schedule, Satisfaction with Life Scale), harmonious passion, and obsessive passion (Passion Scale). Intention-to-treat analyses with 44 participants revealed significant improvements in the MAC group compared to controls. Tennis serve performance improved significantly in the MAC group (pre: 13.18 ± 2.19 to post: 15.09 ± 2.45, t(21) = 7.54, p < .001, d = 0.87) but not in the control group (pre: 13.05 ± 2.33 to post: 12.86 ± 2.41, t(21) = 0.78, p = .442, d = 0.08), with a significant between-group difference at post-test (t(42) = 3.71, p = .001, d = 1.12). Mindfulness skills improved substantially in the MAC group (pre: 39.00 ± 4.18 to post: 52.73 ± 3.65, t(21) = 13.76, p < .001, d = 3.28) compared to controls (pre: 43.55 ± 4.75 to post: 44.32 ± 4.12, t(21) = 1.31, p = .203, d = 0.16), with a significant between-group difference (t(42) = 7.16, p < .001, d = 2.16). Harmonious passion increased significantly in the MAC group (pre: 17.27 ± 2.64 to post: 24.05 ± 4.16, t(21) = 6.15, p < .001, d = 2.57) while remaining stable in controls (pre: 17.86 ± 3.75 to post: 16.91 ± 3.61, t(21) = 1.65, p = .114, d = 0.25), with a significant between-group difference (t(42) = 6.40, p < .001, d = 1.93). Obsessive passion decreased in the MAC group (pre: 23.73 ± 3.66 to post: 16.27 ± 2.86, t(21) = 7.54, p < .001, d = 2.04) while remaining unchanged in controls (pre: 18.00 ± 3.85 to post: 18.41 ± 4.04, t(21) = 0.85, p = .406, d = 0.11), with a significant between-group difference (t(42) =-2.02, p = .050, d =-0.61). Subjective well-being improved markedly in the MAC group (pre: 9.00 ± 7.37 to post: 27.09 ± 7.47, t(21) = 8.37, p < .001, d = 2.45) compared to controls (pre: 4.54 ± 5.85 to post: 8.72 ± 6.08, t(21) = 0.65, p = .526, d = 0.71), with a significant between-group difference (t(42) = 6.85, p < .001, d = 2.07). MAC training represents an effective intervention for enhancing tennis performance, psychological well-being, and adaptive passion while reducing maladaptive passion. These findings support the clinical utility of mindfulness-based approaches in tennis psychology and warrant further investigation on a larger scale.