Optical heart rate monitors provide an accurate alternative to uncomfortable chest strap

In a recent study undertaken by independent research consultancy Progressive Sports Technologies Ltd, based in the Sports Technology Institute, Loughborough University, UK, optical heart rate monitors have gone some way to dispelling the myth that they are not an accurate way of measuring heart rate during exercise.

When testing an electrocardiogram (ECG) against a chest strap and two GPS running watches with built-in optical heart rate sensors, the consultancy found that Epson’s SF-810 device proved comparable to the high quality chest strap heart rate monitor.

Optical heart rate sensors are the latest technology to be integrated into sports watches, measuring heart rate through a system of LEDs and an electro-optical cell, detecting pulsing blood flow under the skin.

The three different heart rate monitors were tested during a 30-minute treadmill exercise (phase one) comprising of supine, standing, low-intensity walking, medium-intensity walking, and high-intensity walking. Following this, the test participants completed an additional 10-minute exercise of low-intensity running and high-intensity running (phase two).

During the first phase of low-intensity exercise the chest strap and optical sensors were tested against an ECG, which is considered one of the most accurate and practical ways of monitoring heart activity. During high intensity exercise, the two optical sensors where tested against a high quality chest strap system.

The results showed that Epson’s optical heart rate monitor was accurate in its measurement, over both courses of exercise. Average heart rate data indicated that the Epson was also more accurate than another leading GPS sports watch and within 0.3% accurate of the chest strap’s data in phase one and 0.7% in the running phase two.

Dr. Bryan Roberts from Progressive Sports Technologies Ltd commented: “There have been concerns about the accuracy of these new optical devices worn on the wrist, but this study suggests these concerns are unfounded. Chest strap heart rate monitors have been the global standard for measuring heart rate during exercise. Looking at average heart rate data over the two exercise periods, we found that Epson’s watch was within 0.3-0.7% accuracy of a leading chest strap monitor.”

Although not known as a sports brand, Epson is one of the world’s leading sensor manufacturers and has been producing heart rate monitors in Japan for a number of years. It has close links to sport, having invented the first electronic timer for the Tokyo Olympic Games in 1964, and most recently its sponsorship of both Manchester United and the MERCEDES AMG PETRONAS Formula One team.

Simon Hanly, product manager at Epson UK, added: “We have invested in this technology for a number of years and it’s pleasing to see that our products have been proven to offer great accuracy.

“Keeping an eye on your heart rate or running according to heart rate zones can help in applying the right effort to prevent burning out before you’ve reached your target and can also be a valuable metric during interval sessions. Logging your heart rate together with other data allows you to assess the training effect, your fitness level, progress and state of recovery.

“Chest straps are the most common monitoring device, but they are uncomfortable and a nuisance to wear. This research means that runners can forget about wearing one and trust the data captured from Epson’s highly advance optical sensor integrated in the watch they’re wearing.”

To find out more about Epson’s range of Runsense and Pulsense devices, please visit www.epson.co.uk/wearables.