• Wearable accelerometers have become the standard method for assessing physical activity for both individuals and field-based research [1]. These new devices allow consumers to have the ability to estimate total energy expenditure and track it over time. • Resting Energy Expenditure plays a critical role in estimating daily total energy expenditure as it contributes 60-70% of total energy expenditure [2,3]. • Little to no information is available to substantiate the validity of these consumer-based activity monitors under free-living conditions.