Commercially-available activity trackers have recently exploded in popularity. Use of an activity tracker has been shown to increase physical activity for some individuals, but abandonment of these devices is high. Many of these activity trackers have been found to be accurate at tracking exercise, though concerns remain about how well these devices track non-traditional movement. This study compares several models of activity trackers for accuracy in step counts while riding a motorcycle a moderate distance.

A motorcyclist wore an Apple Watch (Generation 1) (AW), Fitbit Charge HR (FCH), and a Fitbit Zip (FZ) while completing ten, 14-mile out-and-back trip trials. Step counts of each device were recorded after each trial, and the difference between the number of steps measured by the devices and the actual step counts (zero in all cases) were calculated. All trials contained miscounted steps by all the devices. The average miscounted steps for the AW were 12.9 steps (P<0.05), the FCH miscounted 211.0 steps (P<0.05), and the FZ miscounted 305.3 steps (P<0.05). The range of miscounted steps varied from 2 miscounted steps for the AW to 811 miscounted steps for the FZ. There were also noted differences in step counts between the “out” and “back” portions of the trips. In this study, commercially-available activity trackers were shown to misrepresent riding a motorcycle as step activity. Reported step counts, and therefore distance and calorie information, from these activity trackers should be interpreted with caution among motorcyclists.