DOES THE GARMIN VIVOSMART® HR ACCURATELY MEASURE STEPS AND ENERGY EXPENDITUTE?

Michael A. Smith and Melissa Powers, PhD. University of Central Oklahoma, Edmond, Oklahoma Purpose: The purpose of this study was to evaluate the accuracy of the step counts and energy expenditure (EE) from the Garmin Vivosmart® HR (GVS). Methods: Twenty participants completed 1 mile of walking followed by 1 mile of running on a treadmill in the lab. Participants wore a GVS that was set up for their height, weight, and age in addition to an Actigraph GT3X (GT3X) accelerometer. Data from the GVS were compared to the GT3X for steps and American College of Sports Medicine metabolic equations (ACSMME) for estimated EE. Results: Mean steps counted for walking and running by the GVS was 1956 steps (sd = 219 steps) and 1677 steps (sd = 235 steps) respectively. Mean EE measured for walking and running by the GVS was 88 kcals (sd = 55 kcals) and 127 kcals (sd = 50 kcals) respectively. Mean steps counted for walking and running by the GT3X was 2101 steps (sd = 103 steps) and 1655 steps (sd = 177 steps) respectively. Mean EE estimated by the ACSMME for walking and running was 82 kcals (sd = 12 kcals) and 129 kcals (sd = 19 kcals) respectively. Paired samples t tests were calculated to compare mean steps counted and EE by the GVS and the GT3X for walking and running. Walking step counts from the GVS were significantly different from the GT3X, t(19) = -3.23, p = .004. No significant difference in running step counts from the GVS and GT3X was found, t(19) = .848, p = .407. No significant difference was found between EE from the GVS and ACSMME for the walk, t(18) = 0.571, p = .575, or the run, t(19) = -0.372, p = .714. Conclusion: The GVS may not measure steps accurately at speeds slower than 4.5mph when compared to a validated accelerometer; however, measurements taken at speeds greater than 4.5mph may be accurate. Additionally, the GVS was found to be accurate for calculating EE for both a 1-mile walk and 1-mile run when compared to estimated EE determined by ACSMME