Guidelines recommend that young people engage in muscle-strengthening activities on at least three days per week. The purpose of this study was to examine the impact of a school-based intervention focused on resistance training (RT) for adolescents.
The ‘Resistance Training for Teens’ intervention was evaluated using a cluster randomized controlled trial with 607 adolescents (50.1% female; 14.1±0.5 years) from 16 secondary schools. Teachers were trained to deliver the intervention, which included: (i) an interactive student seminar; (ii) a structured physical activity program, focused on RT; (iii) lunchtime fitness sessions; and, (iv) web-based smartphone apps. The primary outcome was muscular fitness (MF) and secondary outcomes included body mass index (BMI), RT skill competency, flexibility, physical activity, self-efficacy and motivation. Assessments were conducted at baseline, 6- (post-program; primary end-point) and 12-months (follow-up). Outcomes were assessed using linear mixed models, with three potential moderators tested using interaction terms (and sub-group analyses where appropriate).
For the primary outcome (MF), a group-by-time effect was observed at 6-months for upper body (2.0 repetitions, 95% confidence interval [CI]: 0.8 to 3.2), but not lower body (-1.4cm, 95% CI: -4.7 to 1.9). At 6-months, there were intervention effects for RT skill competency and self-efficacy, but no other secondary outcomes. Effects for upper body MF and RT skill competency were sustained at 12-months. Despite overall no effect for BMI, there was a group-by-time effect at 12-months among students who were overweight/obese at baseline (-0.55 kg/m2, 95% CI: -1.01 to -0.08).
The school-based RT intervention resulted in immediate and sustained improvements in upper body MF and RT skill competency, demonstrating an effective and scalable approach to delivering RT within secondary schools.
Corresponding author: David Lubans, PhD, School of Education, Faculty of Education and Arts The University of Newcastle, University Drive, Callaghan NSW Australia 2308, +61 2 4921 2049 (Phone), +61 2 4921 2084 (Fax), David.Lubans@newcastle.edu.au
Source of Funding: This project was funded by the Australian Research Council and the New South Wales Department of Education School Sport Unit.
Conflicts of Interest: There are no conflicts of interest.
Accepted for Publication: 14 August 2017
© 2017 American College of Sports Medicine