儿童体力活动变化趋势特征及其对体适能影响的追踪研究

摘要

Objective: To explore the trajectories and characteristics of physical activity and sedentary behaviorduring 3 years from kindergarten to primary school among children.The effect of different trends of moderate-vigorous physical activity and body mass index on the physical fitness and their interaction were analyzed.Method: A total of 306 preschool children were recruited by 7 kindergartens in Shanghai, 127 (79 boys,48 girls) who participated in both baseline and follow-up study.PA was objectively measured by accelerometer ActiGraphGT3X+. Physical fitness tests were completed according to the corresponding national Fitness Measurement Standards.Multifactor covariance analysis with MVPA trend group, BMI group as independent variables, physical fitness scores in follow-up stage as dependent variable was carried out. Result: Regardless of workday or weekend, time in children's sedentary behavior at baseline was significantly lower than follow-up stage, while time in light physical activity(LPA) and moderate-to-vigorous physical activity (MVPA) were significantly higher than follow-up stage.Boys’ MVPA time onworkdays and weekends were significantly higher than girls (t=3.55, P＜0.01; t=2.86, P＜0.01). The main effect of MVPA trends, BMI group on boys’ grip strength were significant(F=2.736, P＜0.05; F=4.753, P＜0.05). The main effect of both MVPA trends, BMI group andtheir interactionson boys’ upper abdominal muscle strengthwere significant(F=3.126, P＜0.05; F=5.705, P＜0.05; F=7.038, P＜0.01). The main effect of MVPA trends on the boys’ agility was significant(F=3.463, P＜0.05). There was a significant interaction between MVPA trends and BMI group on boys’aerobic fitness(F=2.837, P＜0.05). Conclusion:During 3 years, sedentary behavior on workdays and weekends significantly increased, while LPA and MVPA decreased. There is a significant correlation between children's LPA,MVPAon workdays at baseline and follow-up, but not between sedentary behavior.Continuous active MVPA or increasing MVPA havepositive effects on grip strength, upper abdominal muscle strength and agility in boys.Increasing MVPA time in normal weight boys may have positive effects on upper abdominal muscle strengthand aerobic fitness, but not in obese boys.%目的:探讨自学龄前至小学阶段的3年间儿童静态行为与各强度体力活动水平的总体变化趋势与特征,分析中高强度体力活动不同变化趋势、追踪阶段BMI分组对儿童体适能各指标的影响及其交互作用.方法:在上海市7所幼儿园募集的共306名学龄前儿童中,参与基线与追踪两阶段研究的有效受试对象为127名(男童79名,女童48名),两阶段采用美国产ActiGraphGT3X+客观测量日常体力活动水平,并完成相应年龄段的力量素质、速度/灵敏素质、柔韧素质、有氧耐力等各项体适能测试.以3年间中高强度体力活动(MVPA)变化趋势分组、BMI分组为自变量,追踪阶段体适能指标成绩为因变量,基线体适能指标成绩为协变量,进行多因素协方差分析.结果:无论学习日或双休日,儿童在基线阶段的静态行为时间显著低于追踪阶段,而低强度体力活动(LPA)时间和中高强度体力活动(MVPA)时间则显著高于追踪阶段(均P＜0.01).男童学习日和双休日MVPA时间均显著高于女童(t=3.55,P＜0.01;t=2.86,P＜0.01).MVPA趋势分组、BMI分组对男童握力影响的主效应显著(F=2.736,P＜0.05;F=4.753,P＜0.05);MVPA趋势分组、BMI分组对男童上肢腰腹力量影响的主效应与交互作用均显著(F=3.126,P＜0.05;F=5.705,P＜0.05;F=7.038,P＜0.01);MVPA趋势分组对男童速度/灵敏素质影响的主效应显著(F=3.463,P＜0.05).MVPA趋势分组、BMI分组对男童有氧耐力的影响存在显著交互作用(F=2.837,P＜0.05).结论:3年间,儿童在学习日、双休日的静态行为时间呈显著上升趋势,而LPA、MVPA时间均呈显著下降趋势.随年龄增长,儿童学习日的LPA、MVPA时间相关性显著,而静态行为时间相关性不显著.持续活跃的MVPA水平或提升MVPA时间对于男童的握力、上肢腰腹肌肉力量、速度/灵敏素质均具有正向积极影响.提升MVPA时间对正常体重男童的上肢腰腹肌肉力量、有氧耐力水平具有正向积极影响,但对于超重肥胖男童则不显著.