On an Apple Watch, "core sleep" is another name for light sleep, which scientists also call stages N1-N2. It is not a type of ...

Smoking cessation was associated with significant objective changes in N1 sleep, REM sleep, and SWS among those who maintained abstinence.

REM stages and one REM stage. Ideally, you repeatedly cycle through each stage. Learn how long each stage lasts.

Is sleep tracking actually useful in daily life, or is it just data overload distracting you from what matters? After ...

Oxygen re-saturation during sleep is significantly affected by sleep stage and by cardiovascular and pulmonary comorbidities.

Researchers put forward a comprehensive model outlining the conditions that may give rise to the vivid mental phenomena that ...

The Forerunner 265 is the Rolls-Royce of trackers, with its lengthy list of health and wellness features (relaxation ...

New research shows that reduced time in slow wave and REM sleep is associated with smaller brain volumes in regions ...

Need another reason to prioritize your sleep? Not spending enough time in the two deep stages of sleep may hasten the ...

While anecdotal evidence indicates that sexual activity may improve subsequent sleep, data on objective sleep ... difference in rapid eye movement (REM) sleep between sleeping alone after solo ...

While we dream during REM sleep, the brain is busy processing ... readiness and stress levels at any moment. Yet it's the sleep data that has me mesmerized — and a bit worried.