Centre for Physical Activity and Nutrition Research, Deakin University, 221 Burwood Highway, Burwood, Victoria 3125, Australia.
Br J Sports Med. 2012 Aug;46(10):741-6. doi: 10.1136/bjsm.2011.084921. Epub 2011 May 19.
To investigate the longitudinal changes in children's recess and lunchtime physical activity levels and in the contribution of recess and lunchtime to daily physical activity levels over 5 years among 5-6- and 10-12-year olds.
Data were drawn from two longitudinal studies that were conducted in metropolitan Melbourne, Australia. Boys and girls (n=2782) aged 5-6 years and 10-12 years participated in baseline (T0) measures. Physical activity (n=2490) was measured every 60 s for eight consecutive days using hip-mounted accelerometry. Subsequent measurements were taken at 3-year (T1; n=773) and 5-year (T2; n=634) follow-up. Physical activity intensities were derived using age-adjusted cut-points. Sedentary time was defined as 100 counts/min. Longitudinal data were analysed using three-level (time, child, school) multilevel analyses, stratified by sex and cohort, and adjusted for potential confounding variables.
Significant decreases in recess and lunchtime moderate and vigorous physical activity were observed (p<0.001), with larger decreases occurring in the older cohort. Associated increases were observed in sedentary time over time (p<0.01). Although the contribution of recess to daily moderate intensity physical activity increased in the younger cohort over time (p<0.001), significant decreases were observed in the older cohort (p<0.001).
Physical activity levels during recess and lunchtime decreased in both cohorts over time. Decreases in the contribution of recess and lunchtime to older children's daily physical activity were also observed. Interventions are needed in both primary and secondary schools to promote physical activity levels during recess and lunchtime, particularly during the early years of secondary school.
研究 5-6 岁和 10-12 岁儿童在 5 年内课间和午餐时间体育活动水平的纵向变化，以及课间和午餐时间对儿童每日体育活动水平的贡献。
数据来自澳大利亚墨尔本大都市的两项纵向研究。5-6 岁和 10-12 岁的男孩和女孩（n=2782）参加了基线（T0）测量。使用髋部佩戴的加速度计连续 8 天每秒测量一次身体活动（n=2490）。随后在 3 年（T1；n=773）和 5 年（T2；n=634）随访时进行测量。使用年龄调整的切点得出身体活动强度。久坐时间定义为 100 计数/分钟。使用三级（时间、儿童、学校）多层分析对纵向数据进行分析，按性别和队列分层，并调整潜在混杂变量。
观察到课间和午餐时间中等到剧烈体育活动显著减少（p<0.001），年龄较大的队列减少幅度更大。随着时间的推移，观察到久坐时间增加（p<0.01）。尽管年轻队列的课间时间对每日中度强度体力活动的贡献随着时间的推移而增加（p<0.001），但在年龄较大的队列中观察到显著减少（p<0.001）。
随着时间的推移，两个队列在课间和午餐时间的体育活动水平都有所下降。也观察到课间和午餐时间对较大儿童每日体育活动的贡献减少。需要在小学和中学都进行干预，以促进课间和午餐时间的体育活动水平，特别是在中学的早期阶段。
