Comparative accuracy of fitness tracking modalities in quantifying energy expenditure

The purpose of this study is to compare the accuracy of wrist-worn, consumer-grade pedometers and earbud sensor technology in quantifying energy expenditure. Nineteen participants (24.6 ± 3.1 years) performed 5 min exercise stages on a treadmill (80.5 m/min, 107.3 m/min, 134.1 m/min and 160.9 m/min) while measuring energy expenditure via the Fitbit Charge pedometer and Jabra Sport Pulse Wireless Earbuds, comparing with indirect calorimetry. Paired samples t-tests were used to calculate differences and Pearson correlations to examine associations between kcals measured from the Fitbit and Jabra earbuds from indirect calorimetry. Results indicate significant underestimations of kcals for both devices at all speeds except one (Jabra earbuds at 107.3 m/min). Moderate correlations were observed for the Fitbit at 107.3 m/min and 107.3 m/min, and 134.1 m/min for the Jabra earbuds. Both devices considerably underestimated kcals, suggesting that caution be used when incorporating such data into fitness/health goals.