The Mediating Effects of Mental Fatigue and Mindfulness on the Relationship Between Physical Activity and Quality of Life in Young Adults: Structural Equation Modeling

Objectives: This study explores the impact of physical activity on young adults’ quality of life, with a novel focus on the mediating roles of mental fatigue and mindfulness. Methods: A cross‐sectional study was conducted with undergraduate students studying at a university in Western Turkey (May–June 2024). Data were collected online using validated scales, including the Physical Activity Scale‐2 (PAS‐2), Short Form Health Survey (SF‐12), State Mindfulness Scale (SMS), and Mental Fatigue Scale (MFS). Structural equation modeling (SEM) was employed to assess mediation effects. Results: The structural model also exhibits a good fit, with χ 2 (339) = 627.937, χ 2 /df = 1.852, p < 0.001, RMSEA = 0.045, SRMR = 0.052, CFI = 0.911, GFI = 0.901, TLI = 0.900, and IFI = 0.912. Mental fatigue significantly mediated the relationship between physical activity and quality of life ( β = 0.108; p = 0.030), while mindfulness did not show a significant mediating role. Physical activity had significant positive direct ( β = 0.151; p = 0.010), indirect ( β = 0.108; p = 0.030), and total ( β = 0.259; p = 0.008) effects on quality of life. Conclusion: The results of the study highlight the importance of physical activity in enhancing young adults’ quality of life, particularly by helping to reduce mental fatigue. These results emphasize the need for strategies that promote physical activity as a way to combat mental fatigue and enhance overall well‐being.