Plus, doctors’ number-one pick and their take on the devices.

Add Yahoo as a preferred source to see more of our stories on Google. For years now, we've been told that we have to get enough sleep to maintain our physical and mental health. But in reality, the ...

ATLANTA (AP) — Your watch says you had three hours of deep sleep. Should you believe it? Millions of people rely on phone apps and wearable devices like rings, smartwatches and sensors to monitor how ...