Large Estimate Variations in Assessed Energy Expenditure and Physical Activity Levels during Active Virtual Reality...

The purpose of the study was to compare methods for estimating energy expenditure (EE) and physical activity (PA) intensity during a 30 min session of active virtual reality (VR) gaming. Eight individuals (age = 25.4 ± 2.0 yrs) participated, with a maximal oxygen consumption (VO2max) of 41.3 ± 5.7 mL∙kg−1∙min−1. All tests were conducted over two days. An incremental test to determine the VO2max when running was performed on day 1, while 30 min of active VR gaming was performed on day 2. The instruments used for EE estimations and PA measurements were indirect calorimetry, a heart rate (HR) monitor, and waist- and wrist-worn accelerometer. Compared to indirect calorimetry, waist-worn accelerometers underestimated EE (mean difference: −157.3 ± 55.9 kcal, p < 0.01) and PA levels. HR-based equations overestimated EE (mean difference: 114.8 ± 39.0 kcal, p < 0.01 and mean difference: 141.0 ± 81.6 kcal, p < 0.01). The wrist-worn accelerometer was the most accurate in estimating EE (mean difference: 23.9 ± 45.4 kcal, p = 0.95). The large variations in EE have implications for population-based surveillance of PA levels and for clinical studies using active VR gaming.