Efficacy of using Fitbits to promote physical activity in inactive Victorian adolescents

The aim of this intervention is to evaluate the effectiveness of the Fitbit Flex (and accompanying app) combined with digital behaviour change resources to promote physical activity in inactive adolescents. The intervention is grounded in Social Cognitive Theory and Behaviour Choice Theory. Following the completion of baseline measures, schools will be randomised to either the intervention or wait-list control group. The 12-week intervention will include a Fitbit Flex and accompanying app, weekly individual and/or team missions to complete, and digital behaviour change resources accessed via social media (e.g. infographics, social forums, short videos etc.). Alerts to new ‘missions’ and content will be delivered via email or text message 2-3 times per week. Participants will be asked to wear the monitor as much as possible throughout the 12 weeks. Adolescents will access the resources and be encouraged to participate in 12 missions (delivered at the start of each week) in their own time. Examples of weekly missions include ‘Break it up’, where adolescents will be asked to identify share ideas on how to move more and sit less, ‘Buddy up’, where participants will try to identify and implement ways to help others (e.g. family) to be more active, and ‘Build it up’, where participants will be asked to think about changing one thing that could help them to be more active. The accompanying resources match the weekly themes (e.g. how to set SMARTER goals), will step participants through the behaviour change process and target behaviour change techniques in an interactive, flexible way. The focus of the intervention is the accumulation of physical activity across the day. Adherence to the intervention will be monitored by documenting engagement with the intervention elements (e.g. numbers reporting engagement with resources, social media contributions etc.).