基于加速度传感器的学龄前儿童体力活动簇集特征研究

目的以客观测量的体力活动水平为基础,分析不同持续时间活动的频率及其占总活动时间的比例,从而掌握学龄前儿童体力活动簇集特征。方法根据知情、自愿原则,在上海市杨浦和宝山2个区共招募306名学龄前儿童为受试者,通过连续7 d佩戴加速度传感器ActiGraph GT3X+测量其日常体力活动水平,在此基础上将每次体力活动按强度和持续时间进行分类,并统计不同持续时间的活动平均每天出现的频率及其占总累积活动的比例。结果共有146名受试者男85名,女61名;平均月龄为(57.7±5.0)月]7 d测量数据均有效,被纳入最终统计分析。发现采样间隔为1 s时,学龄前儿童平均每次体力活动持续时间≤4 s,且70%以上的中等强度和大强度体力活动持续时间为2~3 s。结论学龄前儿童体力活动以持续时间较短的零星活动为主。为准确测量学龄前儿童体力活动,特别是中到大强度体力活动水平,宜采用较短的加速度传感器采样间隔(如3 s或更短时间)。

Bout Characteristics of Physical Activity for Pre-school Children Based on Accelerometer

Objective Based on the objectively-measured levels of physical activity,the bout patterns of physical activity in preschool children were examined using high-frequency epoch.Methods Based on informed and voluntary principles,306 pre-school children were recruited in Shanghai's Yangpu District and Baoshan District.Participants’physical activity were assessed using ActiGraph GT3X accelerometers,which were worn for seven consecutive days.Each physical activity is classified by intensity and duration,and then the average daily frequency of activities with different durations and the ratio of the total cumulative activity time were counted.Results A total of 146 participants(boys,85;girls,61;mean age=57.7±5.0 months)had all 7 days of valid measurement data,which were included in the final statistical analysis.Findings of this study indicate that the average duration of each physical activity lasted less than 4 seconds,while more than 70%of the MPA and VPA duration were from 2 to 3 seconds.Conclusions Preschool children’s physical activity is dominated by sporadic activities with short duration.In order to accurately measure the total amount of physical activity in preschool children,especially the moderate to vigorous physical activity,a shorter epoch,such as 3 seconds or even shorter,should be used.