Institute for Social Medicine, Epidemiology and Health Economics, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany.
Institute of Nutritional Medicine, University of Hohenheim, 70599 Stuttgart, Germany.
Int J Environ Res Public Health. 2020 Feb 21;17(4):1401. doi: 10.3390/ijerph17041401.
Physical activity (PA) in youth tends to decline with increasing age, while sedentary behaviour including screen time (ST) increases. There are adolescents, however, whose PA and ST do not follow this pattern. The aim of this study is (i) to examine trajectories in PA and ST from grade 7-9 among students in Berlin, and (ii) to investigate the relationship of these trajectories with individual factors and school type. For the present analyses, changes in students' PA and ST across three time points from 7th to 9th grade were assessed via self-report questionnaires. Positive and negative trajectories were defined for both PA (positive: increasing or consistently high, negative: decreasing or consistently low) and ST (vice versa). Multivariable logistic regression analyses were performed to identify possible predictors of PA and ST trajectories. In total, 2122 students were included (50.2% girls, mean age 12.5 (standard deviation 0.7) years). Compared to grade 7, less students of grade 9 fulfilled PA and ST recommendations (PA: 9.4% vs. 13.2%; ST: 19.4% vs. 25.0%). The positive PA trajectory included 44% of all students (63% boys), while the positive ST trajectory included 21% of all students (30% boys). Being a boy was significantly associated with a positive PA trajectory, while being a girl, having a high socioeconomic status, and attending a high school, were significantly associated with a positive ST trajectory. Different PA and ST trajectories among adolescents should be taken into account when implementing prevention programs for this target group.
青少年时期的身体活动（PA）往往随着年龄的增长而减少，而包括屏幕时间（ST）在内的久坐行为则会增加。然而，有些青少年的 PA 和 ST 并不遵循这种模式。本研究的目的是：（i）在柏林的学生中，从 7 年级到 9 年级，检查 PA 和 ST 的轨迹；（ii）研究这些轨迹与个体因素和学校类型的关系。在目前的分析中，通过自我报告问卷评估了学生在 7 年级到 9 年级的三个时间点的 PA 和 ST 的变化。对于 PA（正：增加或持续高，负：减少或持续低）和 ST（反之亦然）都定义了积极和消极的轨迹。采用多变量逻辑回归分析来确定 PA 和 ST 轨迹的可能预测因素。共有 2122 名学生被纳入（50.2%为女生，平均年龄为 12.5（标准差 0.7）岁）。与 7 年级相比，9 年级符合 PA 和 ST 建议的学生比例较低（PA：9.4%对 13.2%；ST：19.4%对 25.0%）。正 PA 轨迹包括所有学生的 44%（63%为男生），而正 ST 轨迹包括所有学生的 21%（30%为男生）。男生与正 PA 轨迹显著相关，而女生、高社会经济地位和上高中与正 ST 轨迹显著相关。在实施针对这一目标群体的预防计划时，应考虑青少年的不同 PA 和 ST 轨迹。
