Energy expenditure in children predicted from heart rate and activity calibrated against respiration calorimetry

The purpose of this study was to predict energy expenditure (EE) from heart rate (HR) and activity calibrated against 24-h respiration calorimetry in 20 children. HR, oxygen consumption (V˙o 2), carbon dioxide production (V˙co 2), and EE were measured during rest, sleep, exercise, and over 24 h by room respiration calorimetry on two separate occasions. Activity was monitored by a leg vibration sensor. The calibration day (day 1) consisted of specified behaviors categorized as inactive (lying, sitting, standing) or active (two bicycle sessions). On the validation day (day 2), the child selected activities. Separate regression equations forV˙o 2,V˙co 2, and EE formethod 1 (combining awake and asleep using HR, HR2, and HR3), method 2 (separating awake and asleep), andmethod 3 (separating awake into active and inactive, and combining activity and HR) were developed using the calibration data. For day 1, the errors were similar for 24-hV˙o 2,V˙co 2, and EE among methods and also among HR, HR2, and HR3. The met...