Anxiety symptoms and sleep problems typically emerge during adolescence and are frequently intertwined. However, there is a dearth of knowledge concerning their reciprocal influence and whether physical activity might play a protective role in this relationship. The present study aims at filling this gap exploring also the moderating role of sex. 915 13-year-old Swedish adolescents (56% girls) answered a survey conducted four times: at ages 13 (T1), 16 (T2), 19 (T3), and 22 (T4). A random intercept cross-lagged panel model was used. At within-levels, sleep problems and anxiety symptoms had a bidirectional positive association in middle adolescence. Vigorous physical activity and anxiety symptoms showed a reciprocal negative association from middle adolescence. Vigorous physical activity and sleep problems were reciprocally associated only in late adolescence. Associations were the same for girls and boys. This study demonstrated that the relations between anxiety symptoms, sleep problems, and vigorous physical activity cannot be understood without adopting a developmental perspective and that middle adolescence is a crucial period to plan interventions to reduce anxiety symptoms and sleep problems.

焦虑症状和睡眠问题通常出现在青春期，并且经常交织在一起。然而，关于它们的相互影响以及体力活动是否可能在这种关系中发挥保护作用，我们还缺乏了解。本研究旨在填补这一空白，并探索性的调节作用。 915 名 13 岁瑞典青少年（56% 为女孩）回答了一项进行了四次的调查：13 岁（T1）、16 岁（T2）、19 岁（T3）和 22 岁（T4）。使用随机截距交叉滞后面板模型。在内部水平上，睡眠问题和焦虑症状在青春期中期呈双向正相关。从青春期中期开始，剧烈的体力活动和焦虑症状就呈现出相互负相关的关系。剧烈的体力活动和睡眠问题仅在青春期后期才相互关联。女孩和男孩的关联是相同的。这项研究表明，如果不采用发展的视角，就无法理解焦虑症状、睡眠问题和剧烈身体活动之间的关系，并且青春期中期是计划干预措施以减少焦虑症状和睡眠问题的关键时期。