The validity of consumer-level, activity monitors in healthy adults worn in free-living conditions: a cross-sectional study
Open accessAbstract
BACKGROUND: Technological advances have seen a burgeoning industry for accelerometer-based wearable activity monitors targeted at the consumer market. The purpose of this study was to determine the convergent validity of a selection of consumer-level accelerometer-based activity monitors. METHODS: 21 healthy adults wore seven consumer-level activity monitors (Fitbit One, Fitbit Zip, Jawbone UP, Misfit Shine, Nike Fuelband, Striiv Smart Pedometer and Withings Pulse) and two research-grade accelerometers/multi-sensor devices (BodyMedia SenseWear, and ActiGraph GT3X+) for 48-hours. Participants went about their daily life in free-living conditions during data collection. The validity of the consumer-level activity monitors relative to the research devices for step count, moderate to vigorous physical activity (MVPA), sleep and total daily energy expenditure (TDEE) was quantified using Bland-Altman analysis, median absolute difference and Pearson's correlation. RESULTS: All consumer-level activity monitors correlated strongly (r > 0.8) with research-grade devices for step count and sleep time, but only moderately-to-strongly for TDEE (r = 0.74-0.81) and MVPA (r = 0.52-0.91). Median absolute differences were generally modest for sleep and steps (<10% of research device mean values for the majority of devices) moderate for TDEE (<30% of research device mean values), and large for MVPA (26-298%). Across the constructs examined, the Fitbit One, Fitbit Zip and Withings Pulse performed most strongly. CONCLUSIONS: In free-living conditions, the consumer-level activity monitors showed strong validity for the measurement of steps and sleep duration, and moderate valid for measurement of TDEE and MVPA. Validity for each construct ranged widely between devices, with the Fitbit One, Fitbit Zip and Withings Pulse being the strongest performers.
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Fitbit One, Zip and Charge HR, Jawbone Up, LumoBack, and Withings Pulse have all demonstrated excellent test-retest reliability for step count (ICC >.90).
“Fitbit One, Zip and Charge HR, Jawbone Up, LumoBack, and Withings Pulse have all demonstrated excellent test-retest reliability for step count (Intraclass Correlation Coefficient [ICC] >.90) [78-80]”
From Consumer-based wearable activity trackers increase physical activity participation: systematic review and meta-analysis (2019) · cites this paper as [78]
Table 2 (Results; page unavailable) reports step-count ICCs above .90 for Fitbit One and Zip, Jawbone UP, and Withings Pulse. Those ICCs compare the monitors with reference devices; they are not test-retest reliability results. The Methods list neither Fitbit Charge HR nor LumoBack among the devices tested. (LLM, conf=0.88)
Experimental — accuracy not yet measuredNine studies (22 comparisons) examined energy expenditure in free-living settings compared with doubly labeled water and accelerometry.
“Nine studies (22 comparisons) examined energy expenditure in free-living settings compared with the criterion measures of doubly labeled water [104] and accelerometry [29,49,79,101,131,172,174,175].”
From Reliability and Validity of Commercially Available Wearable Devices for Measuring Steps, Energy Expenditure, and Heart Rate: Systematic Review (2020) · cites this paper as [131]
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- Authors
- Ferguson, T., Rowlands, A. V., Olds, T., & Maher, C.
- Affiliations
- University of South Australia (AU)
- Corresponding author
- Maher, Carol
- Venue
- International Journal of Behavioral Nutrition and Physical Activity
- Published
- 2015-03-27
- Volume
- 12
- Issue
- 1
- Pages
- 42-42
- ISSN
- 1479-5868 (ISSN-L)
- PMC
- PMC4416251
- OpenAlex
- W2097760682
- Cited by
- 468
- References
- 28
- Citations by year
- 2026: 17 · 2025: 10 · 2024: 16 · 2023: 17 · 2022: 28 · 2021: 37 · 2020: 55 · 2019: 74 · 2018: 68 · 2017: 80 · 2016: 56 · 2015: 10
- FWCI
- 52.55
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Locations
- International Journal of Behavioral Nutrition and Physical Activity (publishedVersion, cc-by)
- Europe PMC (PubMed Central) (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- UniSA Research Outputs Repository (University of South Australia) (submittedVersion, other-oa)
- Figshare (submittedVersion, cc-by)
- Leicester Research Archive (University of Leicester) (submittedVersion, cc-by)
- Topics
- Health Sciences › Medicine › Physiology › Physical Activity and Health
- Physical Sciences › Computer Science › Computer Vision and Pattern Recognition › Context-Aware Activity Recognition Systems
- Health Sciences › Health Professions › General Health Professions › Mobile Health and mHealth Applications
- Keywords
- wearable accelerometers, convergent validity, step count, moderate-to-vigorous physical activity, sleep duration, total energy expenditure, Fitbit, free-living conditions
- MeSH terms
- Adult, Cross-Sectional Studies, Energy Metabolism, Female, Humans, Male, Middle Aged, Motor Activity, Sleep, Reproducibility of Results, Exercise, Monitoring, Ambulatory, Young Adult, Actigraphy, Accelerometry
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