New York, Feb 13 (IANS): You can trust your smartphone app to track your physical activity, says a new study.

Although wearable devices have received significant attention for their ability to track an individual's physical activity, most smartphone applications are just as accurate, according to the study.

"In this study, we wanted to address one of the challenges with using wearable devices: they must be accurate. After all, if a device is going to be effective at monitoring -- and potentially changing -- behaviour, individuals have to be able to trust the data," said lead study author Meredith A. Case, a medical student at the University of Pennsylvania.

The study tested 10 of the top-selling smartphone apps and devices in the United States by having 14 participants walk on a treadmill for 500 and 1,500 steps, each twice (for a total of 56 trials), and then recording their step counts.

"We found that smartphone apps are just as accurate as wearable devices for tracking physical activity," Case added.

Each of the study participants, all healthy adults recruited at Penn, had the following devices on during the treadmill trials:

At the end of each trial, step counts from each device were recorded.

The data from the smartphones were only slightly different than the observed step counts, but the data from the wearable devices differed more.

"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," said senior author Mitesh S. Patel, an attending physician at the Philadelphia VA Medical Centre.

"Our findings suggest that smartphone apps could prove to be a more widely accessible and affordable way of tracking health behaviours," said Patel.

The study appeared in JAMA: Journal of the American Medical Association.