A decline in adolescents’ moderate-to-vigorous physical activity (MVPA) and the increase in theirsedentary behavior (SB) have been registered all over the world. In order to increase the MVPA and reducethe SB of adolescents, their day has been analyzed by segments of time, verifying the contribution of each tothe daily recommendation of 60 minutes/day. Previous studies have been centered only in physical activitymarkers, but the SB variables were not compared nor the segments of the school-recess with the out-ofschoolperiod or with the weekend. This study aimed to examine the intra- and inter-days differences in theobjectively measured levels of PA and SB in adolescents. A sample of 156 Chilean school students (87 boysand 69 girls; M age=13.41; SD=.67 years) participated in the present study. Participants’ PA and SB wereobjectively measured by a GT3X accelerometer. Overall results showed that only 14% and 9% of Chileanadolescents achieved the daily recommendation of 60 minutes of MVPA on weekdays and the weekend,respectively. School recess was found the best moment for developing MVPA, followed by out-of-schooltime, and ending with weekend days presenting the worst scenario. Regarding the SB, Chilean adolescentswere involved in SB 69.39% of the time on weekdays, and over 70% during the weekend. Different strategiesare discussed in order to increase the MVPA and to decrease SB in each segment of a day.

中文翻译：

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青少年客观测量的身体活动和久坐行为的日内和日间差异

青少年的中度到剧烈运动量（MVPA）下降和其性行为（SB）的增加已在全世界范围内记录。为了增加MVPA并降低青少年的SB，我们按时间段对他们的一天进行了分析，以验证每个人对每天60分钟建议的贡献。先前的研究仅以体育活动标记为中心，但未比较SB变量，也未比较课外休假或周末与学校休假的各个部分。这项研究旨在检验青少年中PA和SB客观测量的日间和日间差异。156名智利小学生（87名男生和69名女生； M年龄= 13.41； SD = .67岁）的样本参加了本研究。用GT3X加速度计客观地测量参与者的PA和SB。总体结果显示，分别只有14％和9％的智利青少年在工作日和周末分别达到60分钟MVPA的每日推荐量。发现学校放假是发展MVPA的最佳时机，其次是课外时间，最后是最糟糕的周末。关于SB，智利青少年的工作日工作时间为69.39％，周末为70％。为了增加MVPA并减少一天中每个时段的SB，讨论了不同的策略。发现学校放假是发展MVPA的最佳时机，其次是课外时间，最后是最糟糕的周末。关于SB，智利青少年的工作日工作时间为69.39％，周末为70％。为了增加MVPA并减少一天中每个时段的SB，讨论了不同的策略。发现学校放假是发展MVPA的最佳时机，其次是课外时间，最后是最糟糕的周末。关于SB，智利青少年的工作日工作时间为69.39％，周末为70％。为了增加MVPA并减少一天中每个时段的SB，讨论了不同的策略。