Socioeconomic disparities in elementary school practices and children's physical activity during school.

Purpose: To examine school socioeconomic status (SES) in relation to school physical activity-related practices and children's physical activity.

Design: A cross-sectional design was used for this study.

Setting: The study was set in 97 elementary schools (63% response rate) in two U.

Elementary school practices and children's objectively measured physical activity during school.

Objective: To examine the relation of physical activity practices covering physical education (PE), recess, and classroom time in elementary schools to children's objectively measured physical activity during school.

Methods: Participants were 172 children from 97 elementary schools in the San Diego, CA and Seattle, WA USA regions recruited in 2009-2010. Children's moderate-to-vigorous physical activity (MVPA) during school was assessed via accelerometry, and school practices were assessed via survey of school informants.