Effects of physical activity and screen-based sedentary behavior on children's mental health and academic performance

Background: The present study examined the current status of physical activity and screen-based sedentary behavior among Chinese children aged 6-12 and explored the relationship between physical activity and screen-based sedentary behavior with children's mental health and academic performance. Methods: : Data were drawn from 2012 children aged 6-12 in three primary schools in China in 2020. Children's mental health was assessed by parents and teachers using the Strengths and Difficulties Questionnaire. Parents reported Children’s physical activity and screen-based sedentary behavior. Children's academic performance assessed by teachers. Binary logistic regressions were used to explore the effects of physical activity and screen-based sedentary behavior on children. Results: : Children aged 6-12 had an average of 2.9 hours of physical activity and 3.7 hours of screen-based sedentary behavior per week. Physical activity (>2h per week) was a protective factor for peer relationship problems (OR=0.62,95%CI:0.49-0.78) and internalizing problems (OR=0.65,95%CI:0.52-0.82) reported by parents. It was also associated with better reading skills (OR=1.33, 95%CI: 1.07-1.65). Screen-based sedentary behavior (>2 hours per week) was a risk factor for ADHD (OR=1.40, 95%CI:1.07-1.83) and externalizing problems (OR=1.28, 95%CI:1.01-1.61) reported by parents. And it was a protective factor for conduct problems (OR=0.65, 95%CI:0.44-0.97), peer relationship problems (OR=0.69, 95%CI:0.51-0.94) and internalizing problems (OR=0.69, 95%CI:0.52-0.93) reported by teachers. Conclusions: : Sufficient physical activity had benefits for children's mental health and academic performance. Screen-based sedentary behaviors longer than 2 hours per week had both beneficial and detrimental effects on different mental health problems, and we recommend that children avoid excessive screen time.