ArticleJMIR formative research2022
Heart Rate Measurement Accuracy of Fitbit Charge 4 and Samsung Galaxy Watch Active2: Device Evaluation Study.
Article in JMIR formative research, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 33 papers.
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Who cites it
33 citing papers in PubMed.
- The Representation of Different Populations in Studies Assessing the Validity of Consumer Wearable Photoplethysmography-Based Measurements: Scoping Review.JMIR mHealth and uHealth · 2026Article
- Physiological Demands and Contributors to Variance of Core Temperature in 162 Recreational Runners during Distance Running in a Warm-Humid Environment.Medicine and science in sports and exercise · 2026Article
- Thyroid function tests and resting heart rate in Graves' disease: a prospective longitudinal study.Endocrine connections · 2026Article
- Comparative Validity of Smartwatch-Derived Heart Rate and Energy Expenditure During Endurance and Resistance Exercise.Sensors (Basel, Switzerland) · 2026Article
- Personalized Machine Learning Intervention to Improve Sleep Quality Using Wearable Technology in Healthy Middle-Aged Adults From Mexico City: Protocol for a Pilot Randomized Controlled Trial.JMIR research protocols · 2026Article
- Digital phenotyping for assessment and prediction of interoception, chronic stress, and self-regulation in adults: a scoping review.Frontiers in digital health · 2026Review
- Validation of heart rate measured by the consumer-level wearable device Fitbit: a cross-sectional observational study.Journal of physical therapy science · 2025Article
- Article
- Adherence to digital pregnancy care - lessons learned from the SMART start feasibility study.NPJ digital medicine · 2025Article
- A continuous real-world dataset comprising wearable-based heart rate variability alongside sleep diaries.Scientific data · 2025Article
- From Stagnation to Strategy: Challenges in Advancing Long COVID Research.Journal of evaluation in clinical practice · 2025Review
- Selective emotion regulation in creative art production: Psychophysiological reactivity during painting reduces anxiety.iScience · 2025Article
- Selecting Wearable Devices to Measure Cardiovascular Functions in Community-Dwelling Adults: Application of a Practical Guide for Device Selection.Mayo Clinic proceedings. Digital health · 2025Review
- Biostrap Kairos Wristband Versus Electrocardiography for Resting Heart Rate Variability Assessment.Sensors (Basel, Switzerland) · 2025Article
- Wrist-Worn and Arm-Worn Wearables for Monitoring Heart Rate During Sedentary and Light-to-Vigorous Physical Activities: Device Validation Study.JMIR cardio · 2025Article
- Effects of a Session of Exergames and Traditional Games on Inhibitory Control in Children With Autism Spectrum Disorder: Randomized Controlled Crossover Trial.JMIR serious games · 2025Article
- Digital applications for diet monitoring, planning, and precision nutrition for citizens and professionals: a state of the art.Nutrition reviews · 2025Review
- Machine Learning Models to Identify Individuals With Imminent Suicide Risk Using a Wearable Device: A Pilot Study.Psychiatry investigation · 2025Article
- Reliability and Accuracy of the Fitbit Charge 4 Photoplethysmography Heart Rate Sensor in Ecological Conditions: Validation Study.JMIR mHealth and uHealth · 2025Article
- Validity of a Consumer-Based Wearable to Measure Clinical Parameters in Patients With Chronic Obstructive Pulmonary Disease and Healthy Controls: Observational Study.JMIR mHealth and uHealth · 2024Observational
Corrections and comments
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Authors and funding
10 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundFitness trackers and smart watches are frequently used to collect data in longitudinal medical studies. They allow continuous recording in real-life settings, potentially revealing previously uncaptured variabilities of biophysiological parameters and diseases. Adequate device accuracy is a prerequisite for meaningful research.
objectiveThis study aims to assess the heart rate recording accuracy in two previously unvalidated devices: Fitbit Charge 4 and Samsung Galaxy Watch Active2.
methodsParticipants performed a study protocol comprising 5 resting and sedentary, 2 low-intensity, and 3 high-intensity exercise phases, lasting an average of 19 minutes 27 seconds. Participants wore two wearables simultaneously during all activities: Fitbit Charge 4 and Samsung Galaxy Watch Active2. Reference heart rate data were recorded using a medically certified Holter electrocardiogram. The data of the reference and evaluated devices were synchronized and compared at 1-second intervals. The mean, mean absolute error, mean absolute percentage error, Lin concordance correlation coefficient, Pearson correlation coefficient, and Bland-Altman plots were analyzed.
resultsA total of 23 healthy adults (mean age 24.2, SD 4.6 years) participated in our study. Overall, and across all activities, the Fitbit Charge 4 slightly underestimated the heart rate, whereas the Samsung Galaxy Watch Active2 overestimated it (-1.66 beats per minute [bpm]/3.84 bpm). The Fitbit Charge 4 achieved a lower mean absolute error during resting and sedentary activities (seated rest: 7.8 vs 9.4; typing: 8.1 vs 11.6; laying down [left]: 7.2 vs 9.4; laying down [back]: 6.0 vs 8.6; and walking slowly: 6.8 vs 7.7 bpm), whereas the Samsung Galaxy Watch Active2 performed better during and after low- and high-intensity activities (standing up: 12.3 vs 9.0; walking fast: 6.1 vs 5.8; stairs: 8.8 vs 6.9; squats: 15.7 vs 6.1; resting: 9.6 vs 5.6 bpm).
conclusionsDevice accuracy varied with activity. Overall, both devices achieved a mean absolute percentage error of just <10%. Thus, they were considered to produce valid results based on the limits established by previous work in the field. Neither device reached sufficient accuracy during seated rest or keyboard typing. Thus, both devices may be eligible for use in respective studies; however, researchers should consider their individual study requirements.
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