There are plenty of gadgets out there that measure your heart rate now – from the one-off pulse readers on phones like the Galaxy S7, to wearables that constantly follow your heartbeats. Their accuracy, however, is not created equal. It seems that measurements vary widely, according to Dr. Gordon Blackburn, a director of cardiac rehab at the Cleveland Clinic.
The team there pitted the Apple Watch against popular competitors like the Fitbit Charge HR, Mio Alpha and Basis Peak (yep, the hot one), and all of those against the gold standard of an electrocardiogram machine, making the 50 or so test subjects walk, run, or simply rest.
It turned out that the Apple Watch was 90% accurate on average, while the other three lingered in the low 80s. The difference, however, stemmed not from the resting heart rate, but from the one measured during physical activity, where the Apple Watch was much more on point. Obviously, it pays off that Apple developed a proprietary system using two light guides that are compared by software to adjust for movements and vasculature changes.