Abstract
BACKGROUND AND OBJECTIVES: Anxiety is closely associated with sleep hygiene among college students; however, its underlying mechanisms require further investigation. This study aimed to construct a moderated mediation model, in which subjective well-being serves as the mediator and physical activity as the moderator, to examine how subjective well-being mediates the relationship between anxiety and sleep hygiene under different levels of physical activity. This model seeks to deepen the understanding of this psychological mechanism and provide a theoretical basis for improving sleep hygiene in college populations. METHODS: Using convenience sampling, a self-reported questionnaire Survey was conducted in 2024 with 3,007 college students (1,267 males and 1,740 females; mean age = 19.03 ± 1.18 years). The study adopted a cross-sectional design and measured four core variables: anxiety, subjective well-being, sleep hygiene, and physical activity. Pearson correlation coefficients were first calculated to assess the relationships among the variables. Mediation and moderated mediation effects were then tested using the PROCESS macro in SPSS. RESULTS: The results indicated that anxiety significantly and negatively predicted sleep hygiene (β = -0.241, p < 0.001), and this effect remained significant after including the mediating variable. Specifically, anxiety significantly and negatively predicted subjective well-being (β = -0.368, p < 0.001), while subjective well-being significantly and positively predicted sleep hygiene (β = 0.262, p < 0.001), suggesting that higher levels of subjective well-being contribute to better sleep hygiene. Furthermore, physical activity significantly moderated the effects of both anxiety on subjective well-being and subjective well-being on sleep hygiene, exhibiting a positive regulatory role. CONCLUSION: This study further elucidates the potential mechanisms through which anxiety affects sleep hygiene among college students. Physical activity serves a buffering role in the relationship among anxiety, subjective well-being, and sleep hygiene. These findings offer a novel perspective for intervention strategies aimed at improving sleep hygiene and provide theoretical support for the integrated management of mental health and health-related behaviors in university populations.