1. Agreement between Fitbit and ActiGraph Estimates of Physical Activity in Young Children.
- Author
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Schmidt, Michael D, Rathbun, Stephen L., Chu, Zhixuan, Boudreaux, Benjamin D., Hahn, Lindsay, Novotny, Eric, Johnsen, Kyle, and Ahn, Sun Joo
- Subjects
PHYSICAL fitness mobile apps ,SEDENTARY lifestyles ,STATISTICS ,WEARABLE technology ,ACTIGRAPHY ,PHYSICAL activity ,RESEARCH funding ,EXERCISE intensity ,DESCRIPTIVE statistics ,SCHOOL children ,DATA analysis ,CHILDREN - Abstract
Physical activity (PA) estimates from the Fitbit Flex 2 were compared to those from the ActiGraph GT9X Link in 123 elementary school children. Steps and intensity-specific estimates of PA and 3-month PA change were calculated using two different ActiGraph cut-points (Evenson and Romanzini). Fitbit estimates were 35% higher for steps compared to the ActiGraph. Fitbit and ActiGraph intensity-specific estimates were closest for sedentary and light PA, while estimates of moderate and vigorous PA varied substantially depending upon the ActiGraph cut-points used. Spearman correlations between device estimates were higher for steps (r
s =.70) than for moderate (rs =.54 to.55) or vigorous (rs =.29 to.48) PA. There was low concordance between devices in assessing PA changes over time. Agreement between Fitbit Flex 2 and ActiGraph estimates may depend upon the cut-points used to classify PA intensity. However, there is fair to good agreement between devices in ranking children's steps and MVPA. [ABSTRACT FROM AUTHOR]- Published
- 2023
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