Wearable Validation in Different Populations
How wearable accuracy changes across older adults, people with heart or mobility conditions, children and other groups, and why healthy-adult results cannot be assumed to apply.
Content last updated . This page has not been medically reviewed.
Why the group tested matters
Most consumer devices are tested on healthy young or middle-aged adults. Accuracy can change with age, body size, health condition and how a person moves. The groups below show what has actually been studied. Evidence labels: established, mixed, insufficient evidence.Summary table
| Group | What the sources show | Label |
|---|---|---|
| Adults overall | Lab accuracy for steps and heart rate is generally good but varies by brand and model; calories are poor | established |
| Older adults | Adequate accuracy for steps, heart rate and ECG in a review of 20 studies; not for respiratory rate | mixed |
| Heart patients | Atrial fibrillation detection varied by device; many tracings inconclusive | mixed |
| People using walking aids | Many wearables counted steps only under specific conditions | insufficient evidence |
| Children | Only a small study with Duchenne muscular dystrophy was read | insufficient evidence |
Adults and the overall picture
A review of 158 publications found devices accurate for steps and heart rate in laboratory settings, but no brand accurate for energy expenditure. [1]Older adults
A systematic review of 20 studies in older adults found wearables had adequate accuracy for step counts, moderate-to-vigorous activity, ECG and heart rate, but not for respiratory rate, with very different data methods and proprietary algorithms across studies; the authors call for standards for older adults. [2] A larger analysis found step-count error differed significantly between older adults and adults. [3] Few studies compared age groups for heart rate or calories. [3]People with heart conditions
In 201 patients at a cardiology service, sensitivity for detecting atrial fibrillation ranged from 58% to 85% and specificity from 69% to 79% across five devices, and 17% to 26% of tracings were inconclusive, so manual review was needed in about one-quarter of cases. [4] A normal watch result does not rule out a heart rhythm problem. See Delayed Medical Assessment and False Reassurance.Children
In 15 children with Duchenne muscular dystrophy and 15 typically developing children, a custom-calibrated waist-worn phone accelerometer estimated step counts with a mean error of about 1.5%. [6] Proper evidence not found in the sources read for general consumer wearables in healthy children or adolescents; this page makes no claim about them.Body size and sex
Across validation studies, error was greater in samples with overweight, and greater for heart rate and calories in studies with more women. [3] These are study-level patterns and do not predict an individual.Practical advice
- Do not assume a study in healthy students applies to you; check who was tested.
- Do not use wearable readings to manage a health condition on your own. Discuss them with your clinician: Discussing Wearable Data With a Clinician.
- See also Device vs Clinical Reference: How Validation Works and Fit, Placement and Skin Characteristics in Wearable Accuracy.
Frequently asked questions
Are wearables accurate for older adults?
For steps, heart rate and ECG, a review found adequate accuracy, but not for respiratory rate, and study methods varied widely. [2]
Can a smartwatch detect atrial fibrillation?
Detection varied by device in a clinic study, with many inconclusive tracings. [4] It does not replace medical evaluation.
Do wearables work for people using crutches or walkers?
Often only under specific conditions in a small simulated study. [5]
What about children?
Proper evidence not found for general consumer devices; one research study used a calibrated accelerometer in children with a muscle disease. [6]
Does body size matter?
Study-level error was greater in overweight samples. [3]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Mobility limits and recovery
A case series of 20 healthy volunteers simulating post-surgery walking with crutches, frames and walkers found commercial wearables counted steps accurately only under specific conditions and should be used cautiously after surgery; an accelerometer worn at the ankle did best. [5] Real patients were not tested.
Other conditions and pregnancy
Proper evidence not found in the sources read for pregnancy, cancer, lung disease or other groups. No accuracy claim is made for them.
References
- Fuller D et al. Reliability and Validity of Commercially Available Wearable Devices for Measuring Steps, Energy Expenditure, and Heart Rate: Systematic Review. JMIR Mhealth Uhealth 2020. PubMed abstract. Read 2026-10-22.
- Alharbi M et al. Data management and wearables in older adults: A systematic review. Maturitas 2019. PubMed abstract. Read 2026-10-22.
- Musa SB et al. Wearable Device Validity in Measuring Steps, Energy Expenditure, and Heart Rate Across Age, Gender, and Body Mass Index. J Phys Act Health 2023. PubMed abstract. Read 2026-10-22.
- Mannhart D et al. Clinical Validation of 5 Direct-to-Consumer Wearable Smart Devices to Detect Atrial Fibrillation: BASEL Wearable Study. JACC Clin Electrophysiol 2023. PubMed abstract. Read 2026-10-22.
- Tsamassiotis S et al. Accelerometers can correctly count orthopaedic patients' early post-operative steps while using walking aids. J Exp Orthop 2025. PubMed abstract. Read 2026-10-22.
- Ramli AA et al. Gait Event Detection and Travel Distance Using Waist-Worn Accelerometers across a Range of Speeds. Sensors 2024. PubMed abstract. Read 2026-10-22.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.