I spent days trying to understand what the charts and graphs were telling ... eight hours a night would require about 1.6 to two hours of sleep in REM sleep and the same amount in deep sleep.

The number of hours needed changes throughout your life, with babies and kids needing more sleep and people 65 and older able to function on slightly less than seven to nine hours. Here’s what ...

Suddenly the hours that I had filled with ideas ... and work out our average sleep time using a calculator or conversion chart. After the first week, I gave up filling it in, easily overwhelmed ...

I'm captivated by my new personal health tracker, a Christmas gift from my husband. It's fascinating to know my heart rate, respiration, activity, readiness and stress levels at any moment. Yet it's ...