Validation of the Actiheart for estimating physical activity related energy expenditure in pregnancy

Background & aims: The objective of this study was to assess the validity of the individually calibrated Actiheart (a combined heart rate and movement sensor device), in pregnant women against indirect calorimetry in a laboratory setting.
Methods: Ten healthy pregnant women (aged 32.9 ± 3.2 yrs, pre-pregnancy BMI = 21.0 ± 2.4 kg/m2, 36.9 ± 2.4 weeks of gestation) walked at 3, 4, 5, and 6 km/h on a treadmill, cycled at 25 W and 50 W on an ergometer and stepped on and off a 15 cm high step. During each routine, AEE was measured simultaneously with the Actiheart (AEEa) and indirect calorimetry (AEEcalo). AEE measurements were compared with paired Student’s t-test, and their agreement with Bland and Altman plots.
Results: The mean AEEcalo was not significantly different from AEEa for any activity except for cycling at 50 W (−45 J/kg/min, p = 0.01). Cumulated AEEa and AEEcalo, combining all activities, were not different (p = 0.9). All data points (100%) fell within ±2SD for all activities except for walking at 6 km/h (89% of data points). All data points fell within ±2SD for the sum of all speeds of walking (3, 4, 5, and 6 km/h).
Conclusions: The Actiheart can be used as a valid method for AEE estimation in pregnant women.