School-based physical activity intervention in 11-13-year-olds: study protocol for cluster randomized controlled trial

Abstract

Background: Targeted strategies to enhance regular physical activity appear to be promising to promote health and well-being of adolescents. This article reports the design of a cluster randomised controlled trial to evaluate the effectiveness of a school-based physical activity programme on the rate and duration of moderate-to-vigorous physical activity, sitting time including screen time, and health-related physical fitness parameters among 11-13 year-old adolescents. Methods: This is a cluster randomized controlled trial conducted in 360 adolescents from government schools in the Colombo Municipal Council area, Sri Lanka. An individual school was considered as a unit of randomization and the 12 selected schools were randomly assigned to one of two groups: control (six schools) and intervention groups (six schools). The intervention group follows a physical activity programme for 30 minutes on three school days per week, for three consecutive months in addition to the standard practice. The primary outcomes are moderate-to-vigorous physical activity rate and duration and sitting time including screen time. Secondary outcomes are the health-related physical fitness parameters: cardiovascular fitness, muscle fitness and flexibility, and body composition. All the outcomes are measured at baseline and three-months following the intervention. Discussion: The outcomes of this study will be an evidence-based intervention programme with the potential to be incorporated into the national education system thus promoting health and well-being of adolescents in Sri Lanka. Trial Registration : Registered at the Sri Lanka Clinical Trials Registry (SLCTR/2018/028).