Sorry, your smartwatch isn’t as accurate as you think


Sensors in today’s smartwatches can detect your heartbeat, track how you sleep and even monitor blood oxygen levels. If Apple gets its way, your watch will be able to track your blood sugar (and possibly send reports about it to your doctor).
If you’ve ever wondered, “Just how accurate are these smartwatch readings?” You’re far from alone, so I took a look. Smartwatches and fitness watches have some serious flaws you should know about.