Related Experiment Video
Updated: Feb 25, 2026
08:45
Assessment of Physical Activity Intensity with Accelerometers and Oxygen Consumption
Published on: June 20, 2025
616
Comparison of two accelerometers for measuring physical activity and sedentary behaviour
Ted Pfister1, Charles E Matthews2, Qinggang Wang3
1Health Technology Assessment and Adoption, Research Innovation and Analytics Portfolio, Alberta Health Services, Calgary, Alberta, Canada.
BMJ Open Sport & Exercise Medicine
|August 2, 2017
Summary
Accurate physical activity measurement is key for disease research. This study found ActiGraph and activPAL accelerometers show significant differences in assessing physical activity and sedentary behavior, indicating they are not interchangeable.
Area of Science:
- Biomedical engineering
- Exercise science
- Public health
Background:
- Accurate assessment of physical activity and sedentary behavior is crucial for understanding disease outcomes.
- Wearable accelerometers are commonly used for objective physical activity monitoring.
Purpose of the Study:
- To evaluate the convergent validity and test-retest reliability of ActiGraph GT3X+ and activPAL3 accelerometers.
- To compare physical activity and sedentary behavior measurements between these two devices.
Main Methods:
- 266 participants wore both ActiGraph and activPAL devices for 7 days.
- Student's t-tests and Bland-Altman plots compared device measurements.
- Intraclass correlation coefficients (ICCs) assessed test-retest reliability over 2 weeks (n=29).
Main Results:
- All physical activity measures differed significantly between ActiGraph (VM/VT) and activPAL3.
- Sedentary behavior estimates were not significantly different between activPAL3 and ActiGraph (VT) (p=0.47) but differed significantly with ActiGraph (VM) (p<0.001).
- High ICCs (0.87-0.93) were observed for most behaviors, except moderate and moderate-to-vigorous activity by ActiGraph (VT) (0.66-0.67).
Conclusions:
- While group-level differences were small, precision between ActiGraph and activPAL3 was low with wide limits of agreement.
- These devices may not be interchangeable for measuring physical activity and sedentary behavior using standard data reduction methods.
