Indexed on: 18 May '16Published on: 18 May '16Published in: Medicine and science in sports and exercise
The main purpose of this study was to examine the accuracy of wristband activity monitors on measuring step counts at prescribed speeds on a treadmill and under short-bouts of common daily activities.Thirty healthy young adults wore three wristband activity monitors on both wrists while walking or jogging on a treadmill at different speeds (54, 80, 107, and 134 m·min) and performing six different common daily activities for 5 minutes each. The monitors included the Fitbit Flex, Garmin Vivofit, and Jawbone UP. The common daily activity conditions included 2 sitting activities (playing a tablet computer game, folding laundry), 2 walking activities (pushing a stroller, carrying a bag), and 2 stair climbing activities (down, up). Absolute percentage error (APE) scores were computed to examine the accuracy between actual observed steps and monitor-detected steps.Under the treadmill condition, the APE ranged between 1.5% and 9.6%. Accuracy was improved at faster speeds (134 m·min) for all the monitors (APE < 2.5%). In the common daily activity conditions, substantial step counts were registered when folding laundry. All monitors significantly underestimated actual steps (all APE >33%) when pushing a stroller. Higher APE was observed when wore on the dominant wrist under the common daily activity conditions.The wristband activity monitors examined were more accurate for measuring step counts between 80 m·min to 134 m·min as compared to a slower speed. Accuracy under each common daily activity condition ranged widely between monitors and activity, with less error when worn on the nondominant wrist. These results will help to inform researchers on the use and accuracy of wristband activity monitors for future studies.