Abstract
BACKGROUND: Smartphone addiction is a growing concern, especially among adolescents, due to its negative impact on health. This study examines how leisure physical activity influence this relationship. OBJECTIVE: This study aimed to investigate the relationship between smartphone addiction and adolescent health, examining the mediating role of loneliness and the moderating effect of leisure physical activity. METHODS: A survey of 1271 Chinese university students was conducted using the PAPS Health and Fitness Scale, Smartphone Addiction Scale, and Leisure Time Exercise Scale. RESULTS: Smartphone addiction negatively affects adolescent health. Loneliness mediates this relationship, while leisure physical activity moderates it. High levels of physical activity reduce the negative impact of loneliness on health (bsimple = -0.49, P < 0.001), whereas low levels enhance this impact (bsimple = -0.21, P < 0.001). CONCLUSION: These research have practical implications for preventing and reducing smartphone addiction and offer a theoretical foundation for promoting healthier lifestyles among adolescents.