St Mary’s Study Discovers Heart Rate Watches are Less Accurate than Traditional Monitors

A new study by the School of Health & Applied Science at St Mary’s University, Twickenham has revealed heart rate (HR) watches are not as accurate as an electrocardiogram (ECG) or chest strap HR monitors.

The research (Hough, Glaister and Pledger, 2017), which tested popular HR watches from Apple, Garmin, Mio and Tom Tom, involved participants having their HR monitored while they cycled at increasing intensities for 15 minutes.

The HR readings from the wrist devices were then compared to those from the ECG, a clinical device that accurately records HR and rhythm, and a traditional chest strap HR monitor.

The results showed that the readings from the watches were less accurate compared to those from the ECG and chest strap HR monitors.

The failure of the watches to consistently produce accurate HR readings match with findings on similar wrist-worn devices.

Previous research suggests inconsistencies in HR readings could be down to excessive hand/wrist movement during running, but, as the participants were cycling, no arm movement was involved during this study.

Lecturer and Lead Sport and Exercise Scientist at St Mary’s Paul Hough, said, “Although wrist-worn monitors are more convenient to wear, have user-friendly apps and offer acceptable levels of accuracy for most people, if people want to record their HR as accurately as possible, I would recommend using a chest strap monitor.”

The study entitled The Accuracy of Wrist-worn Heart Rate Monitors across a Range of Exercise Intensities was published in The Journal of Physical Activity Research.