The Somnia blog

Deep sleep, measured.

What the research actually says about deep sleep, the everyday habits that move it, and how far to trust the wearable on your wrist or finger.

Apple Watch Sleep Accuracy: What Validation Studies Show | Somnia Deep Sleep
apple watch sleep accuracy

Apple Watch Sleep Accuracy: What Validation Studies Show

How accurate is Apple Watch sleep tracking? Three lab studies against polysomnography show it gets total sleep close but misses about half of deep sleep.

Oct 30, 2026
Alcohol and Deep Sleep: What the Studies Measured | Somnia Deep Sleep
alcohol and deep sleep

Alcohol and Deep Sleep: What the Studies Measured

Alcohol can boost deep sleep early in the night, then fragment the rest. Here's what lab studies, a meta-analysis and wearable data actually found.

Oct 29, 2026