Wearable heart rate monitors have become increasingly popular. There are several options available ranging in prices. So which one is most accurate in measuring heart rate during aerobic activity?
About the Study
A recent research study compared five of the optical-based heart rate monitors to determine the precision of each monitor. The Apple Watch, Fitbit Blaze, Garmin Forerunner 235, TomTom Spark Cardio, and Scosche Rhythm+ were tested while participants completed 4 different vigorous exercises in random order: treadmill, stationary bicycle, elliptical trainer with arm levers, and elliptical trainer without levers. An electrocardiograph (ECG) was used to determine accurate heart rates during exercise. Additionally, a Polar H7 chest strap was measured along with each of the optical-based heart rate monitor.
The most accurate device was the Polar H7 chest strap with 0.99 correlation to the results of the ECG. The most accurate optical-based heart rate monitor was the Apple Watch averaging 0.88 correlation. The TomTom (0.74), Garmin (0.67), Scosche Rhythm+ (0.61), and Fitbit (0.56) all averaged below the acceptable accuracy of 0.80. All of the optical-based monitors varied in accuracy depending on the exercise modes with the most accuracy on the treadmill.
If you are measuring your fitness levels using a heart rate monitor, it is best to stick to a chest strap monitor like the Polar H7. The chest straps can be uncomfortable or inconvenient. If this is a concern, consider the Apple Watch. The Apple Watch has the most accuracy and can be easily worn all day without discomfort. Optical-based heart rate monitors are relatively new to the market. As manufacturers improve the technology, these wearable heart rate monitors will become more accurate and be much more worth the money. Until then, stick with the chest strap for the most accurate consumer heart rate monitor.