Adolescents are more likely to experience problematic smartphone use (PSU) due to developmental immaturity. As most previous studies have focused on cross-sectional relationships between PSU, self-control, and physical activity, it is difficult to make valid inferences about their causal relationships and long-term effects. This study aims to investigate the interrelationships between these three variables through a mediation analysis based on a cross-lagged model in a longitudinal design. A total of 2131 participants ( = 12.14, = 2.29, 51.5% female) were surveyed at three time points with 1-year intervals. Smartphone Addiction Proneness Scale (SAPS) and revised Self-Control Scale were used to assess PSU and self-control respectively. Physical activity was measured with an item questioning frequency of physical activity. Cross-lagged model showed that both self-control and physical activity were negatively and bidirectionally associated with PSU. Self-control had a positive predictive effect on physical activity at the next time point. Additionally, self-control positively predicted subsequent physical activity, which in turn negatively predicted subsequent PSU, indicating a mediating effect of physical activity between self-control and PSU. Self-control and physical activity had a long-term effect on reducing the propensity for PSU. Because of the accessibility and operability of physical activity interventions, the public and policy-makers need to prioritize physical activity as an intervention to prevent PSU in adolescents.

中文翻译：

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体力活动和自我控制对青少年智能手机使用问题的长期保护作用：纵向中介分析

由于发育不成熟，青少年更有可能出现智能手机使用（PSU）问题。由于之前的大多数研究都集中在 PSU、自控力和体力活动之间的横向关系，因此很难对其因果关系和长期影响做出有效的推论。本研究旨在通过基于纵向设计中交叉滞后模型的中介分析来调查这三个变量之间的相互关系。共有 2131 名参与者（= 12.14，= 2.29，51.5% 女性）在三个时间点进行了调查，间隔为 1 年。智能手机成瘾倾向量表（SAPS）和修订后的自我控制量表分别用于评估 PSU 和自我控制。身体活动是通过询问身体活动频率的项目来测量的。交叉滞后模型表明，自我控制和体力活动都与 PSU 呈双向负相关。自我控制对下一个时间点的体力活动有正向预测作用。此外，自我控制正向预测随后的身体活动，反过来又负向预测随后的 PSU，表明身体活动在自我控制和 PSU 之间发挥中介作用。自我控制和体力活动对降低 PSU 倾向具有长期影响。由于体育活动干预措施的可及性和可操作性，公众和政策制定者需要优先考虑体育活动作为预防青少年 PSU 的干预措施。