The wearables revolution is gearing up and fitness trackers are leading the charge, feeding users activity data thanks to specialized sensors. But it turns out that your smartphone is just as accurate at tracking physical activity as any wearable on the market, a newly released study shows.
Researchers put 14 subjects through treadmill tests with wearables on wrists and smartphones in pockets. They found that the smartphones were as accurate (and possibly more so) than the wearables in counting steps. The step counts reported by smartphones varied slightly with the actual count (with a range of -6.2 to +6.7 percent difference) while wearables varied far more (with a range of -1.7 to -22.7 percent difference). Admittedly, a treadmill test leaves out any kind of location-based comparisons, but step counts are the basis of most activity trackers’ calculations.
“Since step counts are such an important part of how these devices and apps measure physical activity, including calculating distance or calories burned, their accuracy is key,” says the paper’s senior author, Mitesh S. Patel. “Compared to the 1 to 2 percent of adults in the U.S. that own a wearable device, more than 65% of adults carry a smartphone. Our findings suggest that smartphone apps could prove to be a more widely accessible and affordable way of tracking health behaviors.”
Patel isn’t wrong. Popular fitness tracker Fitbit undoubtedly cut into its own market by releasing a smartphone app that uses the phone’s sensors to almost completely replicate the features of a fitness tracker. What the smartphone doesn’t have, dissenters say, is a singular purpose. After all, we think of email and Candy Crush when we pick up our smartphones–not our daily step count.
The difference is behavioral, not technological: A Fitbit is worn while going about daily tasks while smartphones rarely spend the whole day in your pocket. However, smartphones are only increasing in sophistication, from faster processors to iBeacons. (Heck, they can even detect nuclear radiation.) So if wearables want to move beyond winning on convenience, they’ll have to up their game a bit.