Integrating perceived physical environments and the theory of planned behaviors when explaining adherence to 24-hour movement guidelines in Chinese adolescents.

PURPOSES: Most adolescents worldwide do not meet 24-h movement guidelines, which recommend specific level of physical activity, sedentary behavior, and sleep for optimal health. Nevertheless, there remains a lack of understanding regarding how social cognitive and physical environmental factors influence adolescents' compliance with these guidelines. This prospective study aimed to examine the associations between perceived physical environments, constructs of the theory of planned behavior (TPB), habit strength, and adherence to 24-h movement guidelines in Chinese adolescents over a three-month period. METHODS: A total of 629 Chinese adolescents (Mage = 14.59 years, SD = 0.64) completed a set of questionnaires comprising perceived physical environmental characteristics, constructs of the TPB, habit strength, and 24-h movement behaviors at baseline and 3 months later. Data analysis was conducted using variance-based structural equation modeling. RESULTS: Attitude, subjective norm, and perceived behavioral control had a direct effect on intention and intention had a direct effect on number of the guidelines being met. Habit strength was a significant predictor of adherence to the guidelines, although its moderating effect on the intention-behavior relationship was not significant. Perceived neighborhood facility accessibility, school facility availability, and home physical activity equipment had significant indirect effects on intention through attitude, subjective norm, and perceived behavioral control. However, constructs of the TPB did not serve as mediators in the relationship between perceived physical environments and the number of guidelines being met. CONCLUSION: This study offers preliminary evidence supporting the integration of perceived physical environments and the TPB in predicting adolescents' adherence to 24-h movement guidelines. Future research should consider using experimental study designs with rigorous measures of 24-h movement behaviors to establish causal relationships.

Prospective associations between adherence to 24-hour movement guidelines and mental well-being in Chinese adolescents.

Most evidence regarding the relationships between adherence to 24-hour movement guidelines and adolescent mental health have been derived from cross-sectional studies or have ignored positive mental health indicators. The current prospective study examined the associations between adherence to 24-hour movement guidelines and changes in mental well-being among Chinese adolescents over three months. 816 Chinese adolescents (Mage = 14.76 years; SD = 0.81) completed baseline and follow-up scales of 24-hour movement behaviours, mental well-being, and covariates. Linear mixed-effects models were used for data analyses, with adjustments for covariates and mental well-being at baseline. There was a significant improvement in mental well-being across the three months, and the improvement in mental well-being was positively associated with meeting any single guidelines and both physical activity and sleep guidelines but not adherence to all three guidelines. Meeting both physical activity and sleep recommendations appears to exert more significant benefits on mental well-being than meeting one or two other recommendations. An integrative approach to mental health promotion by focusing on 24-hour movement behaviours (at least physical activity and sleep) may be more effective than focusing on a single behaviour alone.