关键词: 学龄前儿童, 身体活动, 执行功能, 久坐行为, 屏幕时间

Abstract: Objective To know the physical activity condition in preschoolers,and to investigate the association between physical activity and executive function. Methods From May to July in 2018,201 children of middle class in 3 kindergartens in Beijing were recruited using convenience sampling. Participants were asked to wear ActiGraph GT9X for 3 days. Children′s executive function,including inhibition,shift and working memory,were tested through Early Years Toolbox (EYT). Screen time was investigated by self-compiled questionnaires. Results The average time of moderate to vigorous physical activity and total physical activity per day were (95.65±29.02) minutes and (204.58±46.91) minutes,respectively. There were significant differences between boys and girls on the time for mild,moderate,vigorous,moderate to vigorous and total physical activity per day (U=2 593.00,2 136.00,2 440.00,t=4.09,3.68,P<0.05). Screen time per day was (72.84±51.79) minutes,and there was no significant difference between boys and girls (P>0.05). The average scores of working memory,inhibit and shift were 2.40±0.80,0.76±0.16 and 14.08±3.49,respectively,and there was no difference between boys and girls (P>0.05). Correlation analysis indicated that of shift test score was correlated with vigorous intensity physical activity (r=0.199,P=0.040). Children were divided into different groups by whether they met the guidelines criteria of screen time,total physical activity and moderate to vigorous activity,and it was found that there was no difference on EYT score between different groups (P>0.05). Conclusions Daily physical activity is insufficient among preschoolers. Besides,there is a correlation between executive function and physical activity,and the association was influenced by physical activity intensity.

Key words: preschooler, physical activity, executive function, sedentary behaviour, screen time