Agreement between Fitbit and ActiGraph Estimates of Physical Activity in Young Children.
- Resource Type
- Article
- Authors
- Schmidt, Michael D; Rathbun, Stephen L.; Chu, Zhixuan; Boudreaux, Benjamin D.; Hahn, Lindsay; Novotny, Eric; Johnsen, Kyle; Ahn, Sun Joo
- Source
- Measurement in Physical Education & Exercise Science. Apr-Jun2023, Vol. 27 Issue 2, p171-180. 10p. 4 Charts.
- Subject
- *PHYSICAL fitness mobile apps
*SEDENTARY lifestyles
*STATISTICS
*WEARABLE technology
*ACTIGRAPHY
*PHYSICAL activity
*RESEARCH funding
*EXERCISE intensity
*DESCRIPTIVE statistics
*SCHOOL children
*DATA analysis
*CHILDREN
- Language
- ISSN
- 1091-367X
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 (rs =.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]