The effect of a one-year school based physical activity intervention on BMI, waist circumference and overall physical activity level among adolescents in Viken county, Norway: A cluster randomized controlled trial
Abstract
Background: Studies shows that physical activity (PA) level declines from childhood into adolescent, while the prevalence of overweight and obesity increases. PA-interventions in schools have had different success in regard to change this negative spiral.
Objective: Examine the effect of a one-year-school based PA intervention on BMI, waist circumference and overall PA levels amongst adolescent in 9th grade in Viken county, Norway.
Method: The sample in this thesis, is a subgroup from the School in Motion (ScIM) project. A total of 22 schools were invited to participate, out of these 11 agreed to join. All the 9th-grade students in the 11 schools were invited to participate in the study, out of 1149 students, 886 accepted. By lottery, the schools were divided into three intervention arms: Intervention model M1, intervention model M2 and control group. Data collection was conducted from the fall 2017 to summer of 2018. PA and time spent sedentary (SED) were objectively registered over seven consecutive days. Height, weight and waist circumference were measured by a test team from ScIM.
Results: Girls in the intervention groups had a significant increase in WC when compared with controls, with 0.8 cm and 0.9 cm increase in M1 and M2 respectively. Girls and boys in M1 had a significant higher mean difference in change in PA level and time in moderate-to-vigorous PA (MVPA) during school hours. However, there were no significant differences in full day PA, SED or time spent in MVPA for either boys or girls in M1 when compared to controls. Girls and boys in M2 had a significant lower activity level compared to controls, during school hours.
Conclusion: No intervention effect on BMI intervention M1 nor M2. However, an increase in WC was significant for girls in both intervention groups when compared to control group. Intervention M1 had a positive effect on PA level during school hours.
Description
Masteroppgave - Norges idrettshøgskole, 2020