Activity trackers do not appear to improve health even with cash incentives, a year-long study has found
Regularly using an activity tracker or pedometer does not increase activity levels in a way that benefits health, according to a randomised trial involving 800 full-time workers.
Researchers recruited people aged 21 to 65 years old and measured their amount of moderate-to-vigorous physical activity (MVPA) minutes per week, weight, blood pressure cardiorespiratory fitness, and self-reported quality of life at the start of the study, as well as six and 12 months later.
Participants were randomly assigned to one of four groups for the first 6 months of the study:
- Control group: No Fitbit + S$4 (Singapore dollars) weekly payment
- Fitbit group: Fitbit + S$4 weekly payment
- Cash group: Fitbit + S$15 weekly payment to keep for themselves, every week they logged between 50,000 and 70,000 steps, or S$30 if they logged more than 70,000 steps
- Charity group: Fitbit + S$15 weekly payment to donate to charity, every week they logged between 50,000 and 70,000 steps, or S$30 if they logged more than 70,000 steps
In the subsequent 6 months, participants with activity trackers could continue to wear them but were not offered an incentive. The results showed activity trackers can increase activity but not enough to improve health outcomes.
“Over the course of the year-long study, volunteers who wore the activity trackers recorded no change in their step count but moderately increased their amount of aerobic activity by an average of 16 minutes per week,” says lead author Professor Eric Finkelstein, from Duke-NUS Medical School in Singapore.
“However, we found no evidence that the device promoted weight loss or improved blood pressure or cardiorespiratory fitness, either with or without financial incentives.
“While there was some progress early on, once the incentives stopped volunteers did worse than if the incentives had never been offered, and most stopped wearing the trackers,” says Professor Finkelstein.
Cash incentives initially increased physical activity levels but the effects were not long-lasting, say the authors. And health outcomes such as weight and systolic blood pressure did not improve for any of the groups at either six or 12 months.
“Wearable activity trackers are becoming increasingly popular. However, our results show that they are unlikely to be a panacea for rising rates or chronic disease,” write the authors.
They point out that even among a selected group of employees who volunteered to participate in the study, 40% abandoned the Fitbit within six months, and 90% did so by month 12.
“People use these devices for a while, but with time the novelty wear off – this is consistent with how people use trackers in real life,” says co-author Professor Robert Sloan from Kagoshima University, Japan.