AUTHOR=Yu Wanbin , Zhou Xielin , Li Bo TITLE=The relationship between mobile phone addiction and physical activity behavior among university students: the mediating role of bedtime procrastination JOURNAL=Frontiers in Psychology VOLUME=Volume 16 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2025.1603046 DOI=10.3389/fpsyg.2025.1603046 ISSN=1664-1078 ABSTRACT=PurposeTo explore the relationship between mobile phone addiction and physical exercise behavior among college students, and to analyze the mediating effect of bedtime delay between the two, to provide a basis for the development of good behavioral habits among college students.MethodsThe Mobile Phone Addiction Scale, the Physical Activity Behavior Self-Assessment Scale, and the Bedtime Procrastination Scale were administered to 356 college students (49.4% male) in Sichuan Province. Structural equation modeling was then conducted to test the mediating effects.Results(1) There is no gender difference in mobile phone addiction, bedtime procrastination, and physical activity behavior among college students (all p > 0.05). (2) There was a significant negative correlation between college students‘ mobile phone addiction and physical activity behavior (r = −0.688, p < 0.01); a significant positive correlation between college students' mobile phone addiction and bedtime delay (r = 0.730, p < 0.01); and a significant negative correlation between bedtime delay and physical activity behavior (r = −0.658, p < 0.01). (3) Bedtime delay mediates the relationship between mobile phone addiction and physical activity behavior among college students (β = −0.27).Conclusion(1) There is a close relationship between mobile phone addiction, bedtime procrastination, and physical activity behavior among college students; (2) Mobile phone addiction significantly impacts the physical activity behavior of college students. Additionally, it indirectly influences their physical activity behavior through procrastination at bedtime.