Associations between adherence to 24-hour movement behavior guidelines and academic anxiety in Chinese university students: stratified analyses by sex and depressive symptoms

Academic anxiety is a prevalent psychological issue among Chinese university students, significantly impacting their mental health and academic outcomes. Understanding the role of modifiable lifestyle factors, such as 24-hour movement behaviors (24-HMB), is crucial for developing targeted interventions. This study aimed to investigate the associations between adherence to the 24-hour movement behavior (24-HMB) guidelines—encompassing physical activity (PA), sedentary time (ST), and sleep—and academic anxiety among Chinese university students, with particular attention to subgroup differences across sex and levels of depressive symptoms. A cross-sectional study was conducted using an online questionnaire administered to 1,399 Chinese university students aged 18–29 years from universities in Guizhou Province, China. Adherence to PA, ST, and sleep recommendations, as well as depressive symptoms and academic anxiety, were assessed. Associations were examined using multivariable regression models, and stratified analyses by sex and depression severity were performed to explore subgroup-specific association patterns. Adherence to ST (OR = 0.881, 95% CI = 0.821–0.945, p < 0.001) and sleep guidelines (OR = 0.943, 95% CI = 0.894–0.994, p = 0.031) was associated with lower academic anxiety. Adherence to multiple guideline combinations was associated with further reductions in academic anxiety, with the strongest association observed among students meeting all three recommendations (OR = 0.878, 95% CI = 0.838–0.921, p < 0.001). Stratified analyses revealed distinct subgroup-specific patterns: among male students, adherence to ST and PA + ST recommendations was associated with lower academic anxiety, whereas among female students, meeting PA recommendations was associated with higher academic anxiety (OR = 1.123, 95% CI = 1.040–1.213, p = 0.003). Among students with clinically significant depressive symptoms, adherence to ST guidelines (OR = 0.849, 95% CI = 0.764–0.943, p = 0.002) and adherence to all three guidelines (OR = 0.880, 95% CI = 0.820–0.943, p < 0.001) showed the strongest associations with lower academic anxiety. Adherence to the 24-HMB guidelines—particularly reducing sedentary time and ensuring adequate sleep—is associated with lower academic anxiety among university students. These associations are not uniform across the population but vary by sex and depressive symptom severity, suggesting that mental health interventions may benefit from adopting differentiated, subgroup-sensitive approaches.