A sleep specialist says wearing one will not give you an in-depth look at your sleep habits, but it will tell you one thing.

Everything you need to know about photoplethysmography (PPG), the technology behind heart rate measurements in fitness watches and smart rings. When you purchase through links on our site, we may earn ...

Wearable sleep tech, like smart watches or rings that take real-time health metrics, have made it super easy for the average snoozer to track their sleep from one night to the next. But is all that ...