There are over 100,000 fitness apps currently available on app stores, but despite the variety in choice, there has been little evidence they lead to real-world fitness improvements - until now.
Lisa Nguyen
A new study from Marc Mitchell, a Western kinesiology professor and Lisa Nguyen, MSc'24, examined whether fitness app usage can result in long-term exercise habits. Published Sept. 23 in the British Journal of Sports and Medicine, the study offers new, precise insight into how digital tools can support health and activity progress.
The research analyzed data from more than 515,000 Canadian users over a two-year span, resulting in the largest and longest study of a commercial fitness app to date.
The findings showed a modest increase in users' average daily step count over the course of two years. For those who downloaded the app earlier and began with less than 5,000 steps a day, they saw even greater increases, ending the study with an additional 1,000 to 2,000 steps daily.
"Users showed increases in daily step counts at 12 months, and these gains were sustained at 24 months," said Nguyen, a graduate from the Faculty of Health Sciences. "While the increases were more modest at the two-year mark, it was really encouraging that improvements were there. People were still moving more than when they started, which is a very exciting outcome for a digital health app. They weren't downloading the app and then deleting it.
Short-term motivation, long-term behaviour change
Previous research into fitness app usage followed users for much shorter periods of time, often three to six months. Being able to track the activity of users for over two years allowed Nguyen and Mitchell to show that digital health interventions can support long-term behavior change, beyond just short-term boosts.
Marc Mitchell
For Nguyen, this is an incredibly encouraging finding for those seeking to start their health journey today.
"People often think of these apps as only providing short bursts of motivation: you download it, you use it for a few weeks and then you forget about it. But even if the increases were modest, the fact that they were sustained tells us these tools can serve as a long-term support system," she said. "For anyone looking to be more active, using a digital tool like this - grounded in behavioural science theories - can be the difference between setting a goal and sticking with it."
Mitchell wants to see other companies take an individualized approach to goal setting with their technology, as it increases confidence and can drive long-term change.
"I hope there's a greater focus on behavioral science as the digital fitness space grows - ultimately helping people move more - because the benefits of movement are wide-ranging."
Fitness habits created by 12-month mark
Exploring what enables users to stick to their fitness goals was another major aspect of the research, with data showing users were able to not only increase their step count by the 12-month mark, but also cement it as a habit. After that checkpoint, users were less reliant on the app to continue meeting their desired step count daily.
This aligns with behavioural science suggesting habit formation often takes six months to five years depending on the task. Increasing movement in Ontario was heavily dependent on drastic seasonal changes, meaning app users able to sustain their new habit throughout four different seasons, were likely to continue doing so for another four.
Financial incentives used throughout the study - four cents per day if goals were met - proved no longer necessary after one year, when the habit was solidified. For users whose activity was already high when the study began - amassing over 10,000 steps within the first weeks of tracking - financial incentives may have even undermined their progress -the group had a decreased step count after two years; a point the researchers note future app developers should take into consideration.
The fitness app used in the study, Carrot Rewards, saw more than 500,000 users over two years, likely due to itsdesign with a heavy focus on behavioural science, including encouragement for users to keep up use/habits longer.
"The app leveraged the self-determination theory, which is all about making sure it supported users' autonomy, confidence and sense of purpose. That mix of short-term nudges and long-term motivation may explain how users generally sustained physical activity increases across two years," Nguyen said.
While Carrot Rewards is no longer publicly available for download, for those seeking similar results Mitchell recommends searching for apps that include personalized goal setting, gamification elements and clear activity targets.
