Sedentary Activity Time in Elementary School Children in the Safe Routes to School (SRTS) Program

Abstract

PURPOSE: Determine if children achieve the recommended amount of physical activity specified in the Physical Activity Guidelines; determine if children with the most daily sedentary time have the lowest total daily physical activity; determine if children's sedentary time correlates with BMI. METHODS: Children (60 girls, 54 boys), ages 5-12 y, grades 1-6, were recruited from 6 schools in Washington, DC, USA. Each child was categorized by BMI - normal weight (NW, BMI<85%) risk of overweight (ROW, 85%≤BMI<95%), and overweight (OW, BMI≥95%). Each child wore an Actical accelerometer Tuesday-Thursday from 07:00 h to 23:00 h. Accelerometer counts were summed in 1 min epochs. Sedentary activity level was defined as <100 counts per minute. ANOVA, t-tests, and Pearson Product correlations were used for data analyses. Significance was set at p<0.05. RESULTS: Only 22.5% of children recorded 60 minutes or greater of moderate or vigorous physical activity per day. Total daily sedentary time was not significantly different between boys and girls (p = 0.334). No significant differences in sedentary time were found among BMI classifications (F = 1.44, p = 0.241). Total sedentary time increased significantly as age increased (F = 5.13, p < 0.001). Total sedentary time had a strong negative correlation with total daily activity (r = -0.66), average daily activity counts per min (r = -0.64), and daily energy expenditure (kcal/kg/min, r = -0.65). In addition, total sedentary time had a strong negative correlation to light activity (r = -0.66) and moderate activity (r = -0.53) levels. CONCLUSION: Elementary school children do not achieve the national recommendation for physical activity. Daily sedentary time correlates negatively with physical activity. More sedentary time is not correlated with a higher BMI. These results suggest that reducing sedentary time of elementary school children will increase physical activity. Funding: Department of Exercise Science GWU