Peer-reviewed article
Comparison of physical activity and sedentary time measured with the ActiGraph GT3X-BT and Actical accelerometers.
Clark J, Gribbon A, St-Laurent M, Ferrao T, Barnes J et al. ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This study compares two types of accelerometers (Actical and ActiGraph) used to measure physical activity and sedentary time in adults and children. The researchers had 47 adults and 36 children wear both devices for a week and compared how well they agreed. Agreement between the devices varied widely depending on the type of activity measured and the age group studied.
Key points
- Agreement between the two accelerometer devices ranged from poor to excellent across different physical activity intensities
- Significant differences were found in sedentary time and light physical activity measurements across all age groups
- Step count measurements showed significant differences between devices in children and youth
- Moderate-to-vigorous physical activity measurements showed good to excellent agreement in most age groups
- Comparisons between the two device measurements for sedentary time, light activity, vigorous activity and step counts are not recommended
Limitations
This study only compares the technical performance of two measurement devices and does not evaluate the relationship between activity levels and child health outcomes. It cannot tell us whether either device is effective at actually improving children's physical activity or reducing sedentary behaviour.
Abstract
Background Accurate and ongoing assessments of physical activity (PA) and sedentary time (SED) are needed to support public health surveillance, evaluate interventions, and advance the understanding of how movement behaviours relate to health. After six cycles of data collection (2007 to 2019) using the Actical (AC) accelerometer, the Canadian Health Measures Survey (CHMS) transitioned to the ActiGraph wGT3X-BT (AG). To understand how estimates from the AC accelerometer may compare with those from the AG in the context of the CHMS, this study compares AC and AG accelerometer estimates of PA, step counts, and SED using CHMS protocols. Methods A convenience sample of 47 adults (aged 18 to 79 years) and 36 children and youth (aged 3 to 17 years) wore both AC and AG accelerometers on their waist for seven consecutive days. Estimates of PA and SED, step counts, and the percentage of those meeting PA recommendations were compared between the devices using descriptive, correlation, and agreement statistics. Results Agreement ranged from poor to excellent, with variability across PA intensities and age groups. Significant absolute differences in SED and light PA (LPA) were observed across all age groups, and in step counts among children and youth. Agreement was good to excellent across most age groups for moderate-to-vigorous PA (MVPA), and among adults for step counts. While the percentage of those meeting PA recommendations was higher with the AG, results were not statistically different. Similar comparisons could be made with the AG device when using the normal and low frequency extension filters. Interpretation The results of the present study provide data users and researchers with an indication of the expected differences between the devices across various movement behaviour outcomes in the context of the CHMS. Results suggest that comparisons between cycles 1 to 6 and Cycle 7 onward of the CHMS for MVPA are acceptable, but they should be carried out with caution. Comparisons of SED, LPA, vigorous PA, and step counts are not recommended.