Science Daily:

Researchers at Cleveland Clinic put five popular wrist-worn fitness trackers to the test to find out how accurately they gauge heart rate across several types of exercise and intensity levels.

And:

The devices chosen for testing (Apple Watch, Fitbit Blaze, Garmin Forerunner 235, and TomTom Spark Cardio) were based on their popularity and sales figures. Researchers then recorded volunteers’ heart rates at rest and after light, moderate and vigorous exercise across three types of activities, including the treadmill, stationary bike and elliptical (with and without hand levers). Measurements on the wearable devices were compared to readings from the chest strap and EKG.

And:

While the watch-style heart rate monitors may accurately report heart rate at rest, and most were acceptable on the treadmill, they were fairly inaccurate while bicycling or using the elliptical. Of the wrist-worn heart rate monitors, only the Apple Watch provided accurate heart rate readings when participants switched to the elliptical trainer without arm levers; none gave correct measurements when they used arm levers. The wrist and forearm monitors also became less accurate the more intense the activity levels, with the exception of the Apple Watch.

Interesting about the arm levers. Seems to me, this should be part of Apple’s Apple Watch heart rate testing. But still, a solid result.

[H/T Brandon Cosby]