Accuracy of the Garmin Vivoactive 4 for Estimating Heart Rate, Energy Expenditure, and Step Count During Treadmill Exercise

The purpose of this study was to examine the validity of a Garmin wrist-based device for estimating heart rate, energy expenditure, and step count during incremental treadmill exercise in college-aged individuals. Eighteen males and females (mean ± SD age = 23.2 ± 4.9 years) volunteered to complete an incremental treadmill test with the Garmin Vivoactive 4 device and criterion methods (electrocardiogram, indirect calorimetry, and video recording) measuring heart rate, energy expenditure, and step count. Mean absolute percent error (MAPE), simple linear regression, and Bland-Altman plots were used to assess accuracy. Acceptable accuracy was defined as MAPE < 5% for heart rate and < 10% for energy expenditure and step count. Statistical significance was set at α < 0.05. The MAPE (±SD) values were 13.0 (±10.1), 19.1 (±15.0), and 4.6 (±5.3)% for heart rate, energy expenditure, and step count, respectively. The Bland-Altman regression analyses illustrated proportional bias was present for estimations of heart rate (r = 0.591, p < 0.001) and step count (r = 0.516, p = 0.028), but not energy expenditure (r = 0.351, p = 0.153). These findings indicated that the Garmin Vivoactive 4 provided acceptable accuracy metrics for step count, but not heart rate or energy expenditure.