Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article


Master of Science




Mitchell, Marc S.

2nd Supervisor

Prapavessis, Harry.



Mobile health applications (mHealth apps) targeting physical activity (PA) have increased in popularity, yet effectiveness is often limited by low engagement. This study examined the impact of adding a team-based feature, Step Together Challenges (STCs), to an existing incentive-based mHealth app (i.e., Carrot Rewards) on PA. A 24-week retrospective matched pairs study was conducted (n=61,170; pre-intervention: weeks 1-12; intervention: weeks 13-24). Participants who used STCs (experimental group) were matched with those who did not (controls). STC users could earn team incentives for collaboratively reaching individual daily step goals 10 times in seven days. Controlling for pre-intervention mean daily step count, ANCOVA showed a significant difference in intervention average steps per day ( ηp2=0.024). Linear regression show a dose-response relationship between number of STCs completed and intervention mean daily step count (adjusted R2=0.699). Introducing team-based incentives appears to increase PA in an mHealth context.

Summary for Lay Audience

Lack of physical activity is a growing problem around the world. Many smartphone applications aim to help increase users’ physical activity but are often limited by low participant engagement. This study looked at whether adding a team goal component to an existing walking program that rewards users for completing individual step goals increases walking. The study lasted 24 weeks and participants using the team walking feature were compared to those who did not. Individuals using team-based walking goals did in fact walk more than those using only the standard walking program. These findings are important for insurance companies or large corporations looking to improve physical activity for a large number of people as team-based goals may help improve physical activity more than individual goals.