Visualize your sleep cycle architecture and understand when REM sleep occurs throughout the night.
Based on 8 hours of sleep, you'll experience approximately 5 complete sleep cycles.
REM (Rapid Eye Movement) sleep is one of the five stages of sleep and is crucial for memory consolidation, emotional processing, and brain restoration. During REM sleep, your brain is almost as active as when you're awake.
A complete sleep cycle lasts approximately 90 minutes and progresses through these stages:
Stage 1 (N1): Light sleep transition (5% of night). Lasts 5-10 minutes.
Stage 2 (N2): True sleep onset (45% of night). Body temperature drops, heart rate slows.
Stage 3 (N3): Deep sleep / Slow-wave sleep (25% of night). Most restorative stage.
REM: Dream sleep (25% of night). Memory consolidation, emotional processing.
REM sleep becomes progressively longer throughout the night, with the longest REM periods occurring in the final hours before waking. This is why cutting sleep short can significantly impact your REM sleep percentage and cognitive recovery.