Objective Physical education (PE) programs aim to promote physical activity (PA) and reach
most school-aged youth. However, PA levels within PE lessons are often low. In this cluster-
randomized controlled trial, we examined the effects of three self-determination theory-
based motivational strategies on PA and sedentary behavior, as well as their hypothesized
antecedents during PE lessons. Methods Data were collected in Sydney, Australia (October–
December 2011). After baseline testing, teachers (n= 16) and their classes (n= 288 students; …

Background The physical activity (PA) levels of many children and adolescents in Australia
are currently insufficient to promote health benefits. Physical education (PE) programs aim to
promote PA and reach nearly all school-aged children, but PA levels within PE lessons are
often low. PE teachers may influence children's motivation to be physically active in PE
lessons, but little is known about teacher strategies that effectively motivate children to
participate in PA, and few intervention studies have examined motivational strategies in PE …