Department of Sports Science and Clinical Biomechanics, University of Southern Denmark , Odense , Denmark.
Department of Family and Preventive Medicine, University of California San Diego , San Diego, CA , USA.
Front Public Health. 2014 Mar 11;2:20. doi: 10.3389/fpubh.2014.00020. eCollection 2014.
Being outdoors has a positive influence on health among children. Evidence in this area is limited and many studies have used self-reported measures. Objective context-specific assessment of physical activity patterns and correlates, such as outdoor time, may progress this field.
To employ novel objective measures to assess age and gender differences in context-specific outdoor weekday behavior patterns among school-children [outdoor time and outdoor moderate to vigorous physical activity (MVPA)] and to investigate associations between context-specific outdoor time and MVPA.
A total of 170 children had at least one weekday of 9 h combined accelerometer and global positioning system data and were included in the analyses. The data were processed using the personal activity and location measurement system (PALMS) and a purpose-built PostgreSQL database resulting in context-specific measures for outdoor time, outdoor MVPA, and overall daily MVPA. In addition, 4 domains (leisure, school, transport, and home) and 11 subdomains (e.g., urban green space and sports facilities) were created and assessed. Multilevel analyses provided results on age and gender differences and the association between outdoor time and MVPA.
Girls compared to boys had fewer outdoor minutes (p < 0.05), spent a smaller proportion of their overall daily time outdoors (p < 0.05), had fewer outdoor MVPA minutes during the day (p < 0.001) and in 11 contexts. Children compared to adolescents had more outdoor minutes (p < 0.05). During school and within recess, children compared to adolescents had more outdoor MVPA (p < 0.001) and outdoor time (p < 0.001). A 1-h increase in outdoor time was associated with 9.9 more minutes of MVPA (p < 0.001).
A new methodology to assess the context-specific outdoor time and physical activity patterns has been developed and can be expanded to other populations. Different context-specific patterns were found for gender and age, suggesting different strategies may be needed to promote physical activity.
户外活动对儿童健康有积极影响。这方面的证据有限，许多研究都使用了自我报告的测量方法。客观的情境特异性评估，如户外活动时间和中等到剧烈体力活动（MVPA）的模式和相关因素，可能会推动这一领域的发展。
采用新的客观测量方法，评估儿童在上学日特定情境下的户外活动时间和中等到剧烈体力活动（MVPA）的年龄和性别差异，并探讨特定情境下的户外活动时间与 MVPA 之间的关系。
共有 170 名儿童至少有一个上学日的 9 小时组合加速度计和全球定位系统数据，这些数据被纳入分析。数据通过个人活动和位置测量系统（PALMS）和一个专门的 PostgreSQL 数据库进行处理，得出特定情境下的户外活动时间、户外活动 MVPA 和全天 MVPA 的测量结果。此外，还创建和评估了 4 个领域（休闲、学校、交通和家庭）和 11 个亚领域（如城市绿地和体育设施）。多水平分析提供了年龄和性别差异以及户外活动时间与 MVPA 之间关系的结果。
与男孩相比，女孩的户外活动时间较少（p<0.05），全天户外活动时间的比例较小（p<0.05），白天和 11 个情境下的户外活动 MVPA 时间较少（p<0.001）。与青少年相比，儿童的户外活动时间更多（p<0.05）。在上学期间和课间休息时，与青少年相比，儿童的户外活动 MVPA 时间更多（p<0.001），户外活动时间也更多（p<0.001）。户外活动时间增加 1 小时，MVPA 增加 9.9 分钟（p<0.001）。
开发了一种新的评估特定情境下户外活动时间和体力活动模式的方法，可以扩展到其他人群。性别和年龄的不同情境模式表明，可能需要不同的策略来促进体力活动。
