Int J Behav Nutr Phys Act. 2013 Jun 21;10:81. doi: 10.1186/1479-5868-10-81.
Data on longitudinal monitoring of daily physical activity (PA) patterns in youth over successive years is scarce but may provide valuable information for intervention strategies aiming to promote PA.
Participants were 853 children (starting age ~8 years) recruited from 29 Australian elementary schools. Pedometers were worn for a 7-day period each year over 5 consecutive years to assess PA volume (steps per day) and accelerometers were worn concurrently in the final 2 years to assess PA volume (accelerometer counts (AC) per day), moderate and vigorous PA (MVPA), light PA (LPA) and sedentary time (SED). A general linear mixed model was used to examine daily and yearly patterns.
A consistent daily pattern of pedometer step counts, AC, MVPA and LPA emerged during each year, characterised by increases on school days from Monday to Friday followed by a decrease on the weekend. Friday was the most active and Sunday the least active day. The percentage of girls and boys meeting international recommendations of 11,000 and 13,000 steps/day respectively on a Monday, Friday and Sunday were 36%, 50%, 21% for boys and 35%, 45%, 18% for girls. The equivalent percentages meeting the recommended MVPA of >60 min/day on these days were 29%, 39%, 16% for boys and 15%, 21%, 10% for girls. Over the 5 years, boys were more active than girls (mean steps/day of 10,506 vs 8,750; p<0.001) and spent more time in MVPA (mean of 42.8 vs 31.1 min/day; p<0.001). Although there was little evidence of any upward or downward trend in steps/day from age 8 to 12 years, there was a trend toward lower MVPA, LPA and a corresponding increase in SED from age 11 to 12 years.
A weekly pattern of PA occurred in children as young as age 8 on a day by day basis; these patterns persisting through to age 12. In addition to supporting previous evidence of insufficient PA in children, our data, in identifying the level and incidence of insufficiency on each day of the week, may assist in the development of more specific strategies to increase PA in community based children.
关于青少年在连续多年中日常体力活动（PA）模式的纵向监测数据很少，但可能为旨在促进 PA 的干预策略提供有价值的信息。
参与者为 853 名儿童（起始年龄约 8 岁），他们来自澳大利亚 29 所小学。在连续 5 年内，每年佩戴计步器进行为期 7 天的测量，以评估 PA 量（每天的步数），并在最后 2 年同时佩戴加速度计，以评估 PA 量（每天的加速度计计数值（AC））、中度至剧烈 PA（MVPA）、轻度 PA（LPA）和久坐时间（SED）。使用一般线性混合模型检查日常和年度模式。
在每年中都出现了一致的计步器步数、AC、MVPA 和 LPA 的日常模式，其特征是周一至周五的上学日逐渐增加，然后在周末减少。周五是最活跃的一天，周日是最不活跃的一天。每周一、五和日，分别有 36%、50%、21%的男孩和 35%、45%、18%的女孩达到每天 11000 步和 13000 步的国际建议，相应地，每周一、五和日，分别有 29%、39%、16%的男孩和 15%、21%、10%的女孩达到每天 60 分钟以上的推荐 MVPA。在 5 年期间，男孩比女孩更活跃（平均每天步数分别为 10506 步和 8750 步；p<0.001），并且花更多的时间进行 MVPA（平均每天分别为 42.8 分钟和 31.1 分钟；p<0.001）。尽管从 8 岁到 12 岁，每天的步数没有明显的上升或下降趋势，但从 11 岁到 12 岁，MVPA、LPA 呈下降趋势，相应的久坐时间增加。
8 岁的儿童在一天中就出现了 PA 周模式，这些模式一直持续到 12 岁。除了支持之前儿童 PA 不足的证据外，我们的数据还确定了每周每天的不足水平和发生率，这可能有助于制定更具体的策略来增加社区儿童的 PA。
