If physical activity came in a bottle, it would be the most prescribed medicine of all. Just walking 10 more minutes a day may yield clinically significant outcomes such as improved mental health, less pain and better sleep. It can also help prevent and manage more than 100 chronic diseases like cancer, arthritis and diabetes.

And yet, many people do not reap the benefits of just a little more movement — about 10 more walking minutes per day, or an extra 1,000 steps.

There are many digital solutions to help people meet physical activity goals, like fitness apps such as MyFitnessPal and Noom. Unfortunately, the challenges of forming healthy habits remains, and use of fitness apps can fall into a familiar pattern reflecting the difficulty of meeting new fitness goals.

With apps, it might look something like this: the app is downloaded with the best of intentions and is used for a couple of weeks. Gradually, the app becomes neglected and begins to collect dust on a smartphone screen, and eventually is abandoned or deleted.

Encouraging activity

As a physical activity expert, I have made it my life’s work to encourage more people to be more active more often. A hunch eventually led me to explore the idea of actually paying people to exercise as part of my PhD research. That began in 2010 with a small group of cardiac patients.

Fast forward almost 15 years, and it turns out this idea — paying people to exercise — has legs.

Governments and companies all over the world, for instance, have been paying people to exercise for years. And it works! Sort of. In the short-term, at least.

Predictably, when delivered on a population scale, paying people to exercise can get quite expensive, which is a critical limitation. I experienced this limitation firsthand while developing the Carrot Rewards app in partnership with Canadian federal and provincial governments from 2016 to 2019.

In 2019, due to some fiscal constraints, the financial rewards for exercise offered to Canadians for over a year via Carrot Rewards were mostly withdrawn in Ontario (Canada’s largest province) but not in British Columbia and Newfoundland and Labrador (the other two Canadian provinces where the app was available).

This natural variation in financial reward exposure set up an interesting behaviour experiment, which provided the opportunity to answer the question: Can financial rewards be mostly scaled back without negatively impacting physical activity?