Associations of autonomous motivation and physical activity with mobile phone addiction and bedtime procrastination:...

Excessive pre-sleep mobile phone use fuels bedtime procrastination and sleep insufficiency, contributing to a self-reinforcing cycle of dependency. While physical activity benefits sleep health, the reasons for sustained engagement and the role of motivation quality in downstream outcomes remain understudied. This study integrates self-determination theory, compensatory internet use theory, the self-regulatory failure model, and the dual-system model to examine how autonomous motivation operating through physical activity is associated with mobile phone addiction and bedtime procrastination.

In this cross-sectional study, 1,246 Chinese adults, including 389 university students (164 male, 225 female) and 857 working adults (524 male, 333 female), were recruited. The mean age of participants was 32.47 years (SD = 9.86). Validated scales were used to assess autonomous motivation (Behavioral Regulation in Exercise Questionnaire-3), physical activity (Physical Activity Rating Scale-3), mobile phone addiction (Mobile Phone Addiction Index), and bedtime procrastination (Bedtime Procrastination Scale). The data were analyzed using SPSS 23 and AMOS 24. Bootstrapped structural equation modeling was used to estimate the mediation effects and bias-corrected confidence intervals. Indirect effect magnitudes were quantified, and differences between standardized path coefficients (Δβ) were tested via confidence intervals and p-values. Multi-group SEM was used to evaluate model invariance across gender and occupational status.

The mediation analysis confirmed two significant pathways: a behavioral pathway controlling for autonomous motivation (physical activity → mobile phone addiction → bedtime procrastination, β = -0.006, p < .001, 1.6% of the total indirect effect) and an autonomous motivation-driven chain mediation pathway (autonomous motivation → physical activity → mobile phone addiction → bedtime procrastination, β = -0.071, p < .001, 17.8% of the total indirect effect). The autonomous motivation-driven pathway exerted a markedly stronger effect than the behavioral pathway did (Δβ = -0.065, p < .001), highlighting autonomous motivation's amplifying role. Multi-group SEM confirmed full invariance across gender and occupation, supporting model robustness.

This study provides initial evidence that autonomous motivation is associated with sustained physical activity and indirectly associated with lower levels of mobile phone addiction and bedtime procrastination. By contrasting motivation-driven and behavioral pathways within an integrative framework, the findings underscore the relevance of motivation-focused approaches for addressing technology-related sleep problems.