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Determining the Validity and Accuracy of Multiple Activity-Tracking Devices in Controlled and Free-Walking Conditions

Purpose: Clinicians and fitness professionals are increasingly recommending the use of activity trackers. This study compares commercially available activity tracking devices for step and distance accuracy in common exercise settings. Design: Cross sectional. Setting: Rochester, Minnesota. Participants: Thirty-two men (n = 10) and women (n = 22) participated in the study. Measures: Researchers manually counted steps and measured distance for all trials, while participants wore 6 activity tracking devices that measured steps and distance. Analysis: We computed the difference between the number of steps measured by the device and the actual number of steps recorded by the observers, as well as the distance displayed by the device and the actual distance measured. Results: The analyses showed that both the device and walking trials affected the accuracy of the results (steps or distance, P < .001). Hip-based devices were more accurate and consistent for measuring step count. No significant differences were found among devices or locations for the distance measured. Conclusions: Hip-based activity tracking devices varied in accuracy but performed better than their wrist-based counterparts for step accuracy. Distance measurements for both types of devices were more consistent but lacked accuracy.