| Description |
Background: Low levels of physical activity and excessive amounts of sedentary behavior have been associated with higher risk of all-cause mortality as well as the incidence of mortality from numerous chronic diseases. Given the significant impact of physical activity on health, it is important to be able to accurately monitor physical activity, which is often expressed in measures of energy expenditure estimates. The ActiGraph GT3X+ a research-grade accelerometer that has been widely used to estimate amounts of physical activity. However, the validity of the GT3X+ accelerometer for measuring physical activity energy expenditure in young children is not fully understood. Therefore, the purpose of this study was to test the validity of the ActiGraph GT3X+ in estimating energy expenditure in children ages 6-12. Methods: Participants included 12 boys and 11 girls ages 7-12. In a lab setting, participants completed 45 total minutes of activities while wearing an accelerometer on the wrist (ActiGraph GT3X+) as well a portable indirect calorimeter (COSMED K5) as a criterion measure. Energy expenditure estimates from the two devices were then analyzed and compared. Results: Average MET values from the GT3X+ and the K5 differed slightly (-0.31). A paired t-test was performed on the average MET values of the two devices and the energy estimate difference between the two devices was not statistically significant (p=0.17). Conclusions: Based on the data, the ActiGraph GT3X+ provided physical activity energy estimates that are comparable to indirect calorimetry. Very few studies have validated the GT3X+ when worn on the wrist in young children, but this study contributes evidence showing the GT3X+ to be a valid measure for energy expenditure in young children. |
