A Study On The Relationship Between Spatial Distribution Of Students’ Physical Activity And Built Environment Based On Accelerometer,GPS And GIS

Objectives: This study measured students’ physical activity based on accelerometers,used GPS to locate the spatial location of students’ physical activity,and used Arc GIS to calculate the spatial distribution of students’ physical activity as well as the built environment to explore the relationship between built environment and the spatial distribution of students’ physical activity.Methods:(1)Two hundred and sixty-nine students of which 127 were boys and 142 were girls,from two middle schools in Yuhuatai District,Nanjing,were selected as the subjects.The subjects were required to wear accelerometers with GPS locators for 7 consecutive days.(2)Accelerometers were used to measure students’ physical activity;GPS locators were used to locate the spatial position of students’ physical activity.(3)Baidu Map API was requested through Python to obtain six types of AOI data,including green space,commercial center,open space,tourist attraction,scientific and cultural place,and sports and fitness place.(4)Using Arc GIS to add the latest AOI data on the basis of the electronic map of Nanjing,and classify the spatial location of students’ physical activities in Arc GIS to calculate the spatial distribution of students’ physical activities.(5)Using the central locations of different spaces as reference points,a circular buffer zone with a radius of800 m was established using Arc GIS to measure the built-up environment in the buffer zone,including green space density,population density and walkability.(6)Jmp14.0 as well as Spss22.0 were used for statistical analysis of the data.Independent sample t-tests were used to analyze the differences in physical activity between weekdays and weekend days,and between boys and girls.Multiple linear regression was used to analyze the relationship between green space density,population density,and walkability with students’physical activity within different spatial surroundings.Results:1.Measurements of students’physical activity at different intensities:(1)The average daily SB of students was 728.2±208.8 minutes,accounting for approximately 81.2%of the total daily activity time;MVPA was 31.6±16.2minutes(3.5%),accounting for 52.7%of the WHO recommended daily MVPA.(2)Students’LPA,MPA,VPA,and MVPA were higher on weekdays than on weekend days.(3)There were gender differences in physical activity,with boys having higher MPA,VPA,and MVPA than girls on weekdays;boys had significantly higher VPA and lower LPA than girls on weekend days.2.Spatial distribution of students’physical activity:The median MVPA duration of students in different spaces on weekdays was 8.3 minutes(IQR:5.6-14.5)for recreational spaces,with the highest being green spaces;14.0minutes(IQR:9.2-3.7)for school spaces,with 9.2 minutes(IQR:7.0-12.1)for recess;12.7 minutes for transportation;12.7 minutes for transportation trips(IQR:6.9-18.9);and 14.5 minutes for residential spaces(IQR:2.8-30.1).3.Relationship between built environment and students’physical activity in different spaces:(1)In the greenspace neighborhood,walkability was positively correlated with MVPA(β=0.164,p<0.001).(2)In the residential neighborhood,green space density(β=0.202,p<0.001),population density(β=0.382,p<0.001),and walkability(β=0.093,p<0.001)were positively correlated with MVPA.Conclusions:1.Students had a low daily average MVPA of less than 60 minutes on weekdays.Boys performed more VPA and girls performed more LPA,probably because boys tend to participate in organized competitive sports and girls tend to participate more in leisure activities.2.The spatial distribution of students’MVPA on weekdays showed a certain pattern,and the proportion of MVPA to physical activity in the space where they were located was,in order,36.9%for green space,27.5%for recess,and22.9%for transportation.Transportation and the recess activities organized by the school create effective conditions for students to participate in MVPA.There is a relationship between the built environment and the spatial distribution of students’physical activity.Green space with beautiful scenery can stimulate students’participation and motivation in physical activity;in areas with high population density,living and sports facilities are well equipped,which is conducive to students’physical activity;residential environment with high walkability can reduce the need for transportation for students to travel,thus increasing the convenience of participating in physical activity.