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Visualization of Intensity Levels to Reduce the Gap Between Self-Reported and Directly Measured Physical Activity
Published on: March 7, 2019
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Reproducibility of objectively measured physical activity: Reconsideration needed
Eivind Aadland1, Ada Kristine Ofrim Nilsen1, Einar Ylvisåker1
1Faculty of Education, Arts and Sports, Department of Sport, Food and Natural Sciences, Western Norway University of Applied Sciences , Sogndal, Norway.
Journal of Sports Sciences
|March 24, 2020
Summary
The length of accelerometer monitoring for physical activity (PA) reliability depends on data analysis. Shorter monitoring periods may suffice, but analysis methods significantly impact results and required duration.
Area of Science:
- Pediatrics
- Sports Science
- Biomedical Engineering
Background:
- Objective measurement of physical activity (PA) using accelerometers is crucial in pediatric research.
- The reliability of accelerometer data is essential for accurate PA assessment.
- Previous studies suggest varying monitoring durations are needed, but the influence of data resolution is unclear.
Purpose of the Study:
- To compare the reliability of accelerometer-determined PA using different data resolutions.
- To determine the optimal monitoring period length for reliable PA assessment in children.
- To evaluate how different analytical approaches affect the estimation of PA reliability.
Main Methods:
- 221 Norwegian children (2-6 years) wore accelerometers (ActiGraph GT3X+) for 2-3 periods of 14 days.
- Reliability was assessed using intra-class correlation (ICC) for 1-14 days of monitoring.
- Data resolution (hour-by-hour, day-by-day, week-by-week, period-by-period) and Spearman-Brown formula were used for estimation.
Main Results:
- Measured reliability plateaued after 5-6 days of monitoring.
- Estimated monitoring duration to achieve ICC=0.80 varied significantly by data resolution (3.9-87.7 days).
- Reliability could not be accurately estimated from a single data resolution.
Conclusions:
- The analytical approach and data resolution critically influence the perceived reliability of accelerometer-measured PA.
- Current methods for determining monitoring duration may overestimate or underestimate the required period.
- Reconsideration of PA data analysis and interpretation is necessary for accurate reproducibility.
