Elementary physical education: A focus on fitness activities and smaller class sizes are associated with higher levels of physical activity.

Optimizing physical activity during physical education is necessary for children to achieve daily physical activity recommendations. The purpose of this study was to examine the relationship among various contextual factors with accelerometer measured physical activity during elementary physical education. Data were collected during 2015-2016 from 281 students (1st-5th grade, 137 males, 144 females) from a private school located in a metropolitan area of Utah in the U.S. Students wore accelerometers for 12 consecutive weeks at an accelerometer wear frequency of 3 days per week during physical education. A multi-level general linear mixed effects model was employed to examine the relationship among various physical education contextual factors and percent of wear time in moderate-to-vigorous physical activity (%MVPA), accounting for clustering of observations within students and the clustering of students within classrooms. Explored contextual factors included grade level, lesson context, sex, and class size. Main effects and interactions among the factors were explored in the multi-level models. A two-way interaction of lesson context and class size on %MVPA was shown to be statistically significant. The greatest differences were found to be between fitness lessons using small class sizes compared to motor skill lessons using larger class sizes (β = 14.8%, 95% C.I. 5.7%-23.9%  < 0.001). Lessons that included a focus on fitness activities with class sizes that were < 25 students associated with significantly higher %MVPA during elementary physical education.