Sleep Stages Explained: Your Brain's Nightly 4-Part Symphony
Understand N1, N2, N3, and REM sleep stages - what happens in each, why they matter, and how to optimize your natural sleep architecture for better rest.
16 min read
2 articles
Understand N1, N2, N3, and REM sleep stages - what happens in each, why they matter, and how to optimize your natural sleep architecture for better rest.
Sleep trackers use accelerometers, PPG sensors, and algorithms to infer sleep stages. Here's what's actually happening on your wrist and why it's not like medical testing.