Optimize your nights by understanding the biology of your sleep cycles. Learn to calculate your ideal bedtime.
Understanding Sleep Cycles
Quality sleep is composed of several 90-minute cycles, each passing through different phases: light sleep, deep sleep, and REM sleep.
The Different Sleep Phases
- Light sleep (N1-N2): Transition between wakefulness and sleep, easy awakening.
- Deep sleep (N3): Physical recovery, tissue regeneration, immune strengthening.
- REM sleep: Memory consolidation, emotional regulation, dreaming.
How to Calculate Your Ideal Bedtime
To wake up between cycles and avoid grogginess:
- Determine your wake-up time
- Count back in 90-minute increments (add 15 minutes to fall asleep)
- For a 7AM wake-up: go to bed at 11:45 PM or 10:15 PM
Aim for 5 to 6 complete cycles (7.5 to 9 hours of sleep).