Description and Dose of Intervention Components in the ATLAS Intervention

Intervention ComponentDoseDescription
 Teacher professional developmentTwo 6-h workshopsTeachers attend 2 professional development workshops during the study period (preprogram and mid-program). The workshops provide a rationale for the program, outline the intervention strategies (ie, program components, behavioral messages), and explain the theory behind the intervention.
One fitness instructor sessionEach school receives 1 visit during their regularly scheduled sport session from a practicing fitness instructor (ie, personal trainer). The fitness instructor will deliver the session while the teacher observes and completes the session observation checklist.
 Parent newslettersFour newslettersParents of study participants receive 4 newsletters containing information on the potential consequences of excessive screen use among youth, strategies for reducing screen-based recreation in the family home, and tips for avoiding conflict when implementing rules. They are also provided with their child’s baseline fitness test results.
 Researcher-led seminarsThree 20-min seminarsParticipants attend 3 interactive seminars delivered by members of the research team. Seminars provide key information surrounding the program’s components and behavioral messages, including current recommendations regarding youth physical activity, screen-time, and resistance training, and also outline the student leadership component of the intervention.
 Enhanced school sport sessionsTwenty 90-min sessionsSport sessions are delivered by teachers at the study schools. Activities include elastic tubing resistance training, aerobic- and strength-based activities, fitness challenges, and modified ball games. Behavioral messages are reinforced during the cool-down period.
 Lunchtime physical activity–mentoring sessionsSix 20-min sessionsStudents participate in 6 lunchtime physical activity mentoring sessions. These self-directed sessions involve recruiting and instructing grade 7 boys in elastic tubing resistance training.
 Smartphone app and Web site15 wkThe smartphone app and Web site are used for physical activity monitoring, recording of fitness challenge results, tailored motivational messaging, peer assessment of RT skills, and goal setting for physical activity and screen-time.
 Pedometers17 wkParticipants are provided with pedometers for self-monitoring. Students are encouraged to set goals to increase their daily step counts and monitor their progress using the pedometer. Pedometer step counts can also be entered into the smartphone app for review.