Table 1.

Intervention components and implementation evaluation

Level	Intervention component	Dose	Description	Implementation evaluation
Teacher	1) Professional learning workshop	1×5 hour workshop	Professional development workshop for teachers responsible for facilitating the delivery of the B2L programme in their school (hereafter referred to as school champions). The workshop will be delivered by members of the research team (ie, the Principal Investigator and certain Chief Investigators), and will cover information and current evidence on the impact of vigorous physical activity and cardiorespiratory fitness on cognitive functioning and academic performance as well as adolescent mental health. Teachers will participate in practical exercise sessions, where they will be taught about HIIT, and they will also be shown how to use the ’B2L' resources (ie, HIIT task cards, smartphone application). A condensed online version of the workshop will be provided for school champions unable to attend the face-to-face workshop.	Workshop evaluation questionnaire (following workshop completion by school champions). Postprogramme implementation questionnaire (school champions) developed for the current study based on an existing questionnaire.97
	2) Action plan	Once	At the completion of the B2L professional development workshop, teachers will be required to complete an action plan. This will include: timeline, necessary actions, potential barriers and solutions.	Research team will sign-off once completed by school champions in the penultimate session of the workshop.
	3) Session observations	Three observations	The research team will conduct two B2L session observations using the SAAFE observation checklist and provide feedback to the school champions. The school champions will also be asked to observe one B2L session conducted by another school champion at their school.	SAAFE observations49 conducted by research team in terms 2 and 3. SAAFE observation conducted by peer teacher in term 2.
	4) Support from research team	Ongoing	The research team will create a B2L WhatsApp group and invite school champions to join. School champions will be encouraged to use the online messaging platform to share challenges and successful strategies.	Postprogramme implementation questionnaire (school champions). Analysis of WhatsApp engagement.
School	5) Presentation to school staff	1×15 min	School champions will design a tailored presentation, using predesigned programme resources (ie, videos, presentation slides), to be delivered to school faculty during a regularly scheduled staff meeting. The purpose of the presentation is to inform staff of the objectives and details of the B2L programme, and to promote a supportive school climate.	Research team will confirm staff presentation during meeting with school principal.
	6) Equipment	Once	Schools will be provided with a small equipment pack to assist in the delivery of the B2L programme (~$A2500) including: 1×heart rate monitor/student, 1×Bluetooth speaker for playing music during sessions, 1×WASP device (connect Ant+ to WiFi) and a selection of sports equipment (eg, balls, cones).	Postprogramme implementation questionnaire (school champions).
	7) Technique and HIIT session cards	1×set/school champion	B2L technique cards (ie, describing key components to perform each exercise) and HIIT session cards (ie, describing the various HIIT workouts).	Postprogramme implementation questionnaire (school champions).
Student	8) Interactive seminar	1×2 hour seminar	Participating students will attend an interactive seminar delivered by the school champion, but supported by a member of the research team (present on the day of delivery). The interactive seminar will provide an overview of the B2L programme and will address relevant information regarding physical activity, mental health and cognition, using a PowerPoint presentation and embedded videos designed specifically for this project. During this introductory session, students will participate in a practical HIIT session using the B2L smartphone application.	Postprogramme evaluation questionnaire (students)—satisfaction.
	9) HIIT sessions	3/week	Sessions will be run at school during curricular time, supported by programme resources and the B2L app. In phases I and II, teachers will be asked to facilitate the delivery of at least two exercise sessions/week across two school terms (ie, 16 weeks) during regularly scheduled lessons. Participants will be able to select from a variety of predesigned HIIT workouts including: Gym HIIT, Sport HIIT, Class HIIT, Quick HIIT, Hip-hop HIIT, Combat HIIT, Brain HIIT, Rumble HIIT and Custom HIIT. Each exercise session will last approximately 10–15 min in duration. In addition, students will be encouraged to complete additional sessions before or after school, during recess or lunch and during free/study periods using the B2L app. In phase III, students will be encouraged to complete sessions outside of lesson-time (teachers may continue to facilitate the delivery of B2L sessions during lesson-time). Students will also be encouraged to continue the exercise sessions during the school holiday breaks. Two additional HIIT workouts will be provided during this phase (Beach HIIT, Park HIIT) which use the natural environment. Students will be able to select from predesigned HIIT workouts, which may be delivered between 8 and 16 intervals (30 s work, 30 s rest; 1:1 work-to-rest ratio). A shorter option (ie, 8 intervals; 20 s work, 10 s rest; 2:1 work-to-rest ratio; 4 min) will also be provided. Although recommendations will be provided, teachers and students will have the capacity to modify the work-to-rest ratios and number of intervals. Students will be provided with Bluetooth heart rate monitoring technology (Wahoo TICKR), which will connect with the B2L app to display concurrent heart rate data. Students will be encouraged to reach a target intensity of 85% of age-predicted heart rate max. HIIT sessions will include variety and choice of activities to enhance motivation, and will be student self-directed. School champions will facilitate the exercise sessions, but are not expected to guide/deliver the sessions themselves.	Students’ attendance at the activity sessions will be tracked using the B2L app and via teacher recording. Average heart rate during sessions. Postprogramme evaluation questionnaire—session preference, barriers to participation (students).
	10) Smartphone app	Ongoing	A smartphone app has been developed to enable students to complete the B2L sessions at school and home. Android and iOS versions of the app are available. The app includes: (i) descriptions and depictions of exercise sessions, (ii) options for ’solo' or ’group' sessions (for up to six users per device), (iii) timer, audible prompts and display of heart rate using Bluetooth-synced commercial heart rate monitors (Wahoo brand) during HIIT sessions, (iv) personalised reports outlining heart rate (ie, in bpm and % of maximum) achieved overall, and during each work interval across the session, (v) display of HIIT session log on app dashboard to aid self-monitoring and goal setting. A teacher version of the B2L app will also be developed to enable whole class heart rate monitoring for use during scheduled class sessions.	Postprogramme evaluation questionnaire—satisfaction (students). B2L app usage and engagement—number of sessions completed, average heart rate.
Parent	11) e-Newsletters for parents	2×e-newsletters	Parents of intervention group students will receive two e-newsletters containing information on the benefits of physical activity for academic performance and mental health and strategies to support their children’s participation in physical activity during school holiday periods. The e-newsletters will include video content, and will be emailed to parents, unless there is a preferred parental contact method provided by the school.	Postprogramme evaluation questionnaire (student).

B2L, Burn 2 Learn; HIIT, high-intensity interval training; SAAFE, Supportive, Active, Autonomous, Fair, Enjoyable teaching principles.