UC San Diego

Background : Schools provide an important opportunity for children to meet physical activity guidelines. However, physical activity during school is low, and more evidence is needed to support schools to adopt best practices related to physical activity. Objective : The purpose of the present study was to investigate the relation of elementary school physical activity practices related to Physical Education (PE), recess, classroom time, and after -school time to school SES and children's objectively measured physical activity. Methods : Participants were 172 children from 97 elementary schools in the San Diego, CA and Seattle, WA regions. Children wore accelerometers to estimate physical activity for 3.7±1.7 school days. A survey was completed by school informants (PE teachers and principals) to assess physical activity-related school practices (63% response rate). Accelerometer data were scored based on individual school start and end times to derive in-school and after-school minutes/day of MVPA. ANOVAs with LSD post-hoc tests were used to investigate disparities in physical activity-related practices for low -, moderate-, and high-SES schools. Three-level linear mixed effects regression models were used to investigate the association between school practices and children's MVPA. The 5 most important practices, based on their relationship with in-school MVPA, were combined into a summary score. Results : The 5-item school physical activity practice summary score was significantly associated with in-school MVPA, where children had 2.4 more minutes/day of in-school MVPA for every additional practice reflected in the summary score (p = .037). Having a PE teacher was the strongest practice correlated with in -school MVPA, where children at schools with a PE teacher had 6 more minutes/day of in-school MVPA (p = .114). Having someone other than a classroom teacher supervise recess was non-significantly related to 3 more minutes/day of in-school MVPA (p = .363). Conclusions : The present study provides evidence for adopting a package of school physical activity practices to improve children's physical activity during school. Particularly, not having a PE teacher appears to be a leading contributor to low rates of physical activity. Attention should be paid to economically disadvantaged schools, because schools could be contributing to disparities in childhood obesity and inactivity