Effect Of 24-hour Activity Behavior On Physical Growth Of Preschool Children

ObjectivesBy measuring the preschool children’s physical growth indicators,with the analysis of the acceleration sensor,24 h activity physical activity(PA),sedentary behavior(SB)and sleep(SP)level,the use of composition data analysis and component replacement model,comprehensive consideration of 24 h activity behaviors of preschool children’s physical growth combined effect,Provide scientific basis for promoting children’s body growth.MethodsA total of 1080 children aged 3-6 years old from 9 kindergartens in Jiangxi Province were recruited by cluster stratified random sampling method.Parents agreed and signed informed consent.Three axis acceleration sensor was used to measure their daily physical activity level,SP,birth height and weight were investigated by questionnaire,height,weight,shoulder skin fold,upper arm skin fold,head circumference,etc.The z-value of height(HAZ),weight(WAZ)and body mass index(BMI)(BAZ)were calculated by WHO Anthro and WHO Anthro Plus software.The relationship between 24 h activity behavior and body growth index was analyzed by using component data analysis.SP,SB,low intensity physical activity(LPA)and medium and high intensity physical activity(MVPA)were replaced by each other at the same time using component isochronous substitution model,and the influence of time redistribution of 24 h activity behavior on body growth was explored.Results(1)The relative distribution of 24 h activity time was significantly correlated with BMI,HAZ,WAZ and BAZ(P<0.01),and was significantly correlated with height,scapula skin fold and upper arm skin fold(P<0.05).There was no significant correlation with body weight and head circumference(P>0.05).According to the variation matrix,the highest logarithmic ratio variances all involve LPA,and the logarithmic ratio variances with MVPA are the least.(2)MVPA was negatively correlated with WAZ(γ =-0.18,P = 0.039),LPA was positively correlated with height and HAZ(γ = 0.21,P = 0.008;γ = 0.18,P = 0.008),SB was positively correlated with BMI and BAZ(γ = 1.53,P = 0.007;γ = 1.07,P =0.005),SP and body growth index were not significantly correlated.(3)When MVPA was substituted for other activities,the HAZ score increased significantly,and when MVPA and LPA were substituted for each other,the change range was the largest.When SB and SP were replaced by LPA isochronous,HAZ score increased significantly.When SP and MVPA were replaced by LPA isochronous,BAZ scores increased significantly,and when SB was replaced by LPA isochronous,BAZ scores decreased significantly.When the above activities were replaced by SB isochronous,the results were opposite,and there was no statistical significance when other activities were replaced by each other.Conclusions(1)The relative distribution of 24 h activity time of preschool children is closely related to physical growth,and the time spent on LPA is relatively stable.If it changes,the probability of time conversion with MVPA is the highest.(2)In preschool children,LPA had a positive effect on height related body growth index,SB had a positive effect on BMI related body growth index,and MVPA had a negative effect on body weight related body growth index.(3)The replacement of MVPA isochronous for other activities in preschool children had positive physical growth benefits,and the replacement of LPA isochronous had the best physical growth benefits.The effect of isochronous substitution is asymmetric.With the increase of the replacement time of MVPA by SP,SB and LPA,the growth level of the body will decrease slowly,otherwise it will increase rapidly.SP isochronous replacement of LPA and LPA isochronous replacement of SB also have certain physical growth benefits.