ACCURACY OF THE FITSENSE FS-1 SPEEDOMETER DURING WALKING AND RUNNING

Abstract

PURPOSE To examine the accuracy of the FitSense FS-1 Speedometer for estimating distance, speed, and energy expenditure (EE) during walking and running at different speeds and grades. METHODS The study was divided into three parts. Part I: The accuracy of the FitSense for estimating distance during walking and running was investigated during repeated 1600 m trials. Twenty-four participants volunteered for Part I. Part II: The accuracy of the FitSense for estimating speed and EE was examined during level treadmill walking (4.8, 6.4, and 8.0 km · hr−1) and running (8.0, 9.6, and 11.2 km·hr−1). Part III: The accuracy of the FitSense for estimating EE was examined during treadmill walking at a constant speed (4.8 km·hr−1) and selected grades (0.0, 2.5, 5.0, 7.5, and 10%). Twelve of the original 24 subjects completed Parts II and III. RESULTS Part I: The FitSense accurately estimated walking distance, but it underestimated running distance by an average of 3.5% (P = 0.016). Part II: The FitSense overestimated speed during walking and running at 8.0 km·hr−1 (P < 0.001). In addition, the device underestimated EE at two walking speeds (6.4 and 8.0 km·hr−1) (P < 0.01). No significant differences were found for speed or EE predictions while running on a level grade. Part III: The FitSense was unable to detect the rise in metabolic demand associated with increasing treadmill grades. CONCLUSION The FitSense FS-1 Speedometer was accurate for estimating distance and speed during level walking (4.8 and 6.4 km·hr−1) and running (9.6 and 11.2km·hr−1). However, the FitSense overestimated speed and underestimated EE in the transition between walking and running (8.0 km·hr−1). In addition, the FitSense underestimated EE during uphill walking.