Apple Watch most accurate in measuring heart rate, energy expenditure

Accuracy is pivotal in providing quality care, but many wearables used to monitor cardiovascular health have not been extensively evaluated for accuracy. A study, published in the Journal of Personalized Medicine, tested seven of the most popular wrist-worn devices for accuracy in heart rate monitoring and energy expenditure.

Considering the popularity of wrist-worn wearables, the study aimed to provide a wearable sensor evaluation framework to ensure patients and providers are receiving accurate results.

The study evaluated the Apple Watch, Basis Peak, Fitbit Surge, Microsoft Band, Mio Alpha 2, PulseOn and Samsung Gear S2 for accuracy on heart rate and energy expenditure. Sixty participants performed 80 tests on the devices by wearing them while simultaneously being evaluated with continuous telemetry and indirect calorimetry when sitting, walking, running and cycling.

Results showed devices had the lowest rate of error when participants were cycling and the highest rate when walking. Participants who were male, had a higher body mass index or darker skin tone had the highest rates of device error. None of the devices scored an energy expenditure error below 20 percent. Overall, the Apple Watch reported the lowest error rates in both heart rate and energy expenditure while the Samsung Gear S2 reported the highest error rates.

“Individuals and practitioners should be aware of the strengths and limitations of consumer devices that measure heart rate and estimate energy expenditure,” concluded Anna Shcherbina of the Division of Cardiovascular Medicine at the Department of Medicine at Stanford University, first author on the study, and colleagues. “We encourage transparency from device companies and consistent release of validation data to facilitate the integration of such data into clinical care. We provide a forum for the community to share such data freely to help achieve this end.”