Pedometer smartphone apps may be inaccurate: study

Several popular free pedometer apps which are designed to track your fitness are seriously flawed and have "an unacceptable error percentage", a new study has claimed.

Researchers from the University of Toronto ran three free pedometer apps, Accupedo, Moves and Runtastic, through a series of tests to measure their accuracy.

Each is compatible with Android and Apple smartphones and gathers step stats via the phones' built-in accelerometres, Global Positioning System (GPS) navigation tools or a combination of both.

Subjects used the apps in a variety of scenarios. Most basic was a simple, 20-step test during which they wore a traditional pedometer on their hip and held the phone in their hand.

In each instance, the pedometer was pretty much accurate, but the phone apps were off by about five percent. Similar results were found after a 40-step stair climb test, a treadmill test and three days of unstructured regular activity.

Researchers also found that the tools were not quite as smart as they claimed. When one researcher found her phone tallied steps when she was actually stuck in traffic, they were inspired to add a driving test. They found that with each app, the GPS tool interpreted slow car motion as walking.

"There is 'an unacceptable error percentage in all of the applications when compared to the pedometer,'" researchers said.

"Self-evaluation can be very effective in lifestyle change as well, so it is important that people are getting the most accurate information possible and using tools they can trust," said Krystn Orr from University of Toronto.

"The traditional pedometer is probably the most reliable and cost-effective tool for tracking your steps," Orr added.

The findings were published in the journal BMC Research Notes.