Waking up in the middle of a sleep cycle leaves you groggy. Time your sleep to wake up at the end of a cycle for maximum alertness.
You should go to bed at
10:00 PM
6 Cycles (9h)
11:30 PM
5 Cycles (7.5h)
01:00 AM
4 Cycles (6h)
02:30 AM
3 Cycles (4.5h)
The Science of Sleep Cycles
Sleep is not a uniform state. Throughout the night, your brain cycles through distinct stages: Light Sleep, Deep Sleep, and REM (Rapid Eye Movement) Sleep.
A typical complete sleep cycle lasts about 90 minutes.
Why You Feel Groggy (Sleep Inertia)
If your alarm goes off while you are in Deep Sleep, your brain is forced to jump from Delta waves (slow, restorative) to Beta waves (awake) instantly. This causes "Sleep Inertia"—that heavy, disoriented feeling that coffee barely fixes.
However, if you wake up at the end of a cycle (during Light Sleep), your brain is already near wakefulness. This makes getting out of bed feel natural and easy.
Recommended Sleep Duration
7.5 Hours (5 Cycles): The gold standard for most adults.
9 Hours (6 Cycles): Great for athletes or those recovering from illness.
6 Hours (4 Cycles): The minimum for functionality, but not optimal for long-term health.
Tips for Better Sleep
Consistency is King: Going to bed and waking up at the same time anchors your Circadian Rhythm.
Darkness: Your brain needs darkness to produce Melatonin. Use blackout curtains or a sleep mask.
Cool Temp: The optimal room temperature for sleep is around 65°F (18°C).
