Light-intensity activities are important for estimating physical activity energy expenditure using uniaxial and triaxial accelerometers

This study evaluated the validity of the total energy expenditure (TEE) estimated using uniaxial (ACCuni) and triaxial (ACCtri) accelerometers in the elderly. Thirty-two healthy elderly (64–87 years) participated in this study. TEE was measured using the doubly labeled water (DLW) method (TEE DLW ). TEE ACCuni (6.79 ± 1.08 MJ day −1 ) was significantly lower than TEE DLW (7.85 ± 1.54 MJ day −1 ) and showed wider limits of agreement (−3.15 to 1.12 MJ day −1 ) with a smaller correlation coefficient ( r = 0.703). TEE ACCtri (7.88 ± 1.27 MJ day −1 ) did not differ from TEE DLW and showed narrower limits of agreement (−1.64 to 1.72 MJ day −1 ) with a larger correlation coefficient ( r = 0.835, P