'Cause when I see someone wearing an Apple Watch, and they post it after their workout-

'Cause when I see someone wearing an Apple Watch, and they post it after their workout- Really? You burned 1,500 calories in an hour? Exactly how inaccurate are these devices? Well, luckily for us, Stanford Medicine already did a study on the seven most popular devices that check your heart rate and track your calories, and this is what they've come up with. Out of the seven most popular wristbands, that study actually shows they're really great at measuring heart rate. Six out of the seven wristbands came within 5% of someone's actual heart rate. However, when it comes to measuring calories burned, not so much. In fact, every single device bombed the test. One device was off by a whopping 93%. People are using these devices to make real health decisions in their life. But right now, these wristbands aren't being held to strict medical guidelines. If you're using any of these fitness trackers, I would trust it for your heart rate. But when it comes to counting calories, I would take that information with a grain of salt. If you want to learn more about digging deeper on other subjects, subscribe.