A Three-year Follow-up Study On The Physical Activity Characteristics And Influencing Factors Of Children And Adolescents In Nantong, Nanjing

Background:Physical inactivity has become the fourth leading risk factor for death in the world,and physical activity generally declines with age,especially in adolescence,when maintaining high levels of physical activity may confer lifelong benefits.The purpose of this study is to find out the physical activity characteristics of children and adolescents and explore the dynamic changes of factors affecting their physical activity,so as to provide references for the use of targeted physical activity promotion interventions in different grades.Methods:A total of 875 subjects?438 male students and 437 female students?from nanjing and nantong primary schools,junior high schools and senior high schools were recruited in this study.The national physical fitness monitor meeting the requirements of the national physical health standards for students?revised in 2014?was adopted for measurement,and the Body Mass Index?BMI?of the students was calculated.=body weight?kg?/height 2?m 2?).Students'BMI was divided according to the BMI threshold of different age groups corresponding to different genders in the BMI classification standard for overweight and obesity screening of Chinese school-age children and adolescents?2004?.The subjects wore the accelerometer?ActiGraph GT3X?for 7 consecutive days to collect the data of physical activity,and the physical activity intensity was classified according to the Evenson Children?2008?standard.Students with MVPA?60min were classified as the group meeting the standard,while those with MVPA<60min were classified as the group meeting the standard.SAS JMP14 software was used for statistical processing of the data,and mean±standard deviation?M±SD?was used to describe the data conforming to normal distribution.Analysis of gender,grade,and regional differences between using independent sample t test,the overall data of the three years can the multi-factor analysis of variance of repeated measurement data,the questionnaire and physical activity time data using single factor analysis of logistic?p<0.1 that may influence,enter the stepwise regression analysis?and multiple factors logistic stepwise regression analysis(p_in=0.05,p_out=0.1).Results:According to the needs of the study,the data of 479 valid subjects?222 male and 257 female?were used in this study.1.Physical activity:in the 3 years of continuous tracking,through the analysis of variance of repeatable measurement data,there were significant differences in the time of sitting,time of mild physical activity and time of MVPA among the 3 measurements?p<0.01?.There were significant differences in time of sitting,time of mild physical activity and time of MVPA among all grades?p<0.01?.The time of sitting,the time of mild physical activity and the time of MVPA were significantly different between the sexes?p<0.05?.2.Influencing factors:influencing factors of primary school students:in the first year,inadequate off-campus facilities of B8?OR=4.954,95%ci:1.618-15.171?and parents'non-support?OR=2.662,95%ci:1.073-6.604?are protective factors for primary school students to reach MVPA standards;The absence of outdoor sports venues near the home?OR=0.176,95%ci:0.040-0.771?is a risk factor for the MVPA attainment of primary school students.In the second year,low maternal literacy?OR=0.220,95%ci=0.090-0.539?was a risk factor for MVPA attainment among primary school students.In the third year,physical education is very tired?OR=0.527,95%ci=0.272-1.024?,the father's education level is low?OR=0.275,95%ci=0.089-0.848?,their participation in extracurricular sports activities is less?OR=0.427,95%ci=0.182-1.003?are the risk factors for MVPA attainment of primary school students.Influencing factors of junior high school students:low educational level of A10 mothers in the first year?OR=0.136,95%ci:0.047-0.396?is a risk factor for MVPA attainment of junior high school students.In the second year,low participation in extracurricular physical activities?OR=0.220,95%ci=0.076-0.640?and non-student?OR=0.097,95%ci:0.010-0.919?were risk factors for junior high school students to reach the MVPA standard.In the third year,the absence of an indoor gym near home?OR=0.093,95%ci:0.009-0.923?was a risk factor for MVPA attainment in junior high school students.Factors affecting high school students:in the first year,feeling very tired?OR=0.625,95%ci:0.423-0.924?was a risk factor for high school students to reach MVPA standards,and housework?OR=2.597,95%ci=1.189-5.670?was a protective factor for high school students to reach MVPA standards.There were no significant factors in the second year.In the third year,housework?OR=3.993,95%ci:1.279-12.467?was a protective factor for MVPA attainment in high school students.Conclusion:1.Physical activity level1)The overall level of physical activity of students is low.The changes of physical activity of students do not always increase or decrease,but show a fluctuating and decreasing trend.The overall MVPA compliance rate is at a low level?7.93%¹2.74%?,among which the percentage of male students?13.96%¹9.37%?is higher than that of female students?2.72%⁸.17%?.2)The physical activity level of girls is significantly lower than that of boys,which is manifested as more sitting time than boys,less LPA time and MVPA time than boys.3)The physical activity level of children and adolescents in Nantong is lower than that in nanjing,and the MVPA compliance rate is also lower than that in Nanjing.4)The higher the grade,the longer the sitting time?primary school<junior high school<senior high school?,while the time of light physical activity decreased with the increase of grade?primary school>junior high school>senior high school?.2.Physical activity related factors1)With the increase of grade,the number of influencing factors of physical activity gradually decreased.2)The type of students?whether they live in school or not?has a great influence on the MVPA of junior and senior high school students.3)the presence of open Spaces,green Spaces,gymnasiums and parks near the home can effectively promote the MVPA to promote or reduce SB time.4)Junior high school students who like or actively participate in sports activities can promote MVPA,while senior high school students'MVPA is mainly affected by the degree of subjective fatigue.5)Controlling"screen time"for grade 6 pupils can effectively promote MVPA.