Why Do I Wake Up Exactly 4 Hours After Falling Asleep Every Night?
That 3-4 hour wake-up isn't broken sleep—it's your brain transitioning between sleep stages. Here's why it happens and what actually helps.
8 min read
3 articles
That 3-4 hour wake-up isn't broken sleep—it's your brain transitioning between sleep stages. Here's why it happens and what actually helps.
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.