Department of Endocrinology and Metabolism, Peninsula College of Medicine and Dentistry, Plymouth University Campus, Plymouth, UK.
BMJ. 2012 Sep 27;345:e5888. doi: 10.1136/bmj.e5888.
To determine whether, and to what extent, physical activity interventions affect the overall activity levels of children.
Systematic review and meta-analysis.
Electronic databases (Embase, Medline, PsycINFO, SPORTDiscus) and reference lists of included studies and of relevant review articles.
Design: randomised controlled trials or controlled clinical trials (cluster and individual) published in peer reviewed journals.
incorporated a component designed to increase the physical activity of children/adolescents and was at least four weeks in duration.
measured whole day physical activity objectively with accelerometers either before or immediately after the end of the intervention period.
INTERVENTION effects (standardised mean differences) were calculated for total physical activity, time spent in moderate or vigorous physical activity, or both for each study and pooled using a weighted random effects model. Meta-regression explored the heterogeneity of intervention effects in relation to study participants, design, intervention type, and methodological quality.
Thirty studies (involving 14,326 participants; 6153 with accelerometer measured physical activity) met the inclusion criteria and all were eligible for meta-analysis/meta-regression. The pooled intervention effect across all studies was small to negligible for total physical activity (standardised mean difference 0.12, 95% confidence interval 0.04 to 0.20; P<0.01) and small for moderate or vigorous activity (0.16, 0.08 to 0.24; P<0.001). Meta-regression indicated that the pooled intervention effect did not differ significantly between any of the subgroups (for example, for total physical activity, standardised mean differences were 0.07 for age <10 years and 0.16 for ≥ 10 years, P=0.19; 0.07 for body mass index across the entire range and 0.22 for exclusively overweight/obese children, P=0.07; 0.12 for study duration ≤ 6 months and 0.09 for >6 months, P=0.71; 0.15 for home/family based intervention and 0.10 for school based intervention, P=0.53; and 0.09 for higher quality studies and 0.14 for lower quality studies, P=0.52).
This review provides strong evidence that physical activity interventions have had only a small effect (approximately 4 minutes more walking or running per day) on children's overall activity levels. This finding may explain, in part, why such interventions have had limited success in reducing the body mass index or body fat of children.
确定体育活动干预是否以及在何种程度上影响儿童的整体活动水平。
系统评价和荟萃分析。
电子数据库（Embase、Medline、PsycINFO、SPORTDiscus）和纳入研究及相关综述文章的参考文献列表。
设计：随机对照试验或对照临床试验（集群和个体）发表在同行评议的期刊上。
纳入旨在增加儿童/青少年体力活动的组成部分，且持续时间至少为四周。
在干预期结束前后，使用加速度计客观测量全天体力活动。
对每项研究的总体力活动、中等强度或剧烈体力活动时间或两者进行干预效果（标准化均数差）的计算，并使用加权随机效应模型进行汇总。元回归探讨了研究参与者、设计、干预类型和方法学质量与干预效果异质性的关系。
30 项研究（涉及 14326 名参与者；6153 名参与者接受加速度计测量的体力活动）符合纳入标准，均适合进行荟萃分析/元回归。所有研究的综合干预效果对于总体力活动为小到微不足道（标准化均数差 0.12，95%置信区间 0.04 至 0.20；P<0.01），对于中等强度或剧烈活动为小（0.16，0.08 至 0.24；P<0.001）。元回归表明，任何亚组之间的综合干预效果差异均不显著（例如，对于总体力活动，年龄<10 岁的标准化均数差为 0.07，年龄≥10 岁的标准化均数差为 0.16，P=0.19；整个范围内的体重指数的标准化均数差为 0.07，仅超重/肥胖儿童的标准化均数差为 0.22，P=0.07；研究持续时间≤6 个月的标准化均数差为 0.12，研究持续时间>6 个月的标准化均数差为 0.09，P=0.71；家庭/基于家庭的干预的标准化均数差为 0.15，学校为基础的干预的标准化均数差为 0.10，P=0.53；高质量研究的标准化均数差为 0.09，低质量研究的标准化均数差为 0.14，P=0.52）。
本综述提供了强有力的证据表明，体育活动干预对儿童的整体活动水平只有很小的影响（每天大约多走或跑 4 分钟）。这一发现可能部分解释了为什么此类干预措施在降低儿童的体重指数或体脂肪方面收效甚微。
