Accuracy of Fitness Trackers and Smartphone Apps

Wearable devices and smartphone apps now provides pedometer functions and more but are they as accurate? A study, led by researchers at the Perelman School of Medicine at the University of Pennsylvania tested a range of gadgets and smartphones to find out.

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.

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

• Waistband: one pedometer and two accelerometers
• Wrists: three wearable devices
• Pants pockets: two smartphones, one running three apps and the other running one

The devices being compared in the study includes the Samsung Galaxy S4, iPhone 5S, Fitbit Flex, Fitbit One, Nike’s Fuelband, and the Jawbone UP24.  Smartwatches were not included in the study.

The results showed that smartphones and its apps are quite accurate in tracking the number of steps. It has a deviation of only -6.7 to 6.2 percent from the observed step counts. Wearable devices, however, have larger deviations that ranges from -22.7 to -1.5 percent.

Accuracy of step counts are important since other metrics like distance traveled and calories burned are based on the them.

Comparing between the wearable devices, the Fitbit One and Fitbit Zip are seen to be the most accurate. While the Nike Fuel Band is the least accurate.

This is good news for those who don’t own a fitness tracker yet. It means that your smartphone is just as good as long as it is the latest model.

And since more people have smartphones than fitness trackers, it means that checking for a healthy lifestyle is very much within reach for everyone.

How about you? What fitness app or fitness device are you using?