"I only got 7 hours. I'm going to be a zombie today."
We have been brainwashed by the number 8. We treat it like a magical threshold: 7 hours and 59 minutes is failure, 8 hours is success.
This obsession has a name: Orthosomnia (the perfectionistic pursuit of ideal sleep). And ironically, it is causing insomnia.
Here is the truth: 8 hours is an average, not a prescription. And Quality is far more important than Quantity.
The "Time in Bed" Trap
Imagine you go to bed at 10 PM and wake up at 7 AM. "I slept for 9 hours!" you say.
But did you?
- It took you 30 minutes to fall asleep.
- You woke up for 10 minutes at 2 AM to use the bathroom.
- You stared at the ceiling for 20 minutes at 5 AM.
Your Time in Bed was 9 hours. Your Total Sleep Time was 8 hours. Your Sleep Efficiency was 88%.
Sleep Efficiency = (Total Sleep Time / Time in Bed) x 100
If you spend 10 hours in bed but only sleep for 6, your efficiency is 60%. That is "junk sleep." It is fragmented, shallow, and unrefreshing.
Why Shorter Can Be Better
In Cognitive Behavioral Therapy for Insomnia (CBT-I), we often use Sleep Restriction. We force patients to spend less time in bed (e.g., 6 hours).
Why? To increase Sleep Pressure. By compressing the sleep window, the brain learns to sleep efficiently. No more tossing and turning. You hit the pillow and pass out. 6 hours of solid, deep, consolidated sleep is infinitely better than 8 hours of broken, light sleep.
Listen to Your Cycles, Not the Clock
Remember, sleep comes in 90-minute cycles.
- 5 cycles x 90 mins = 7.5 hours
- 6 cycles x 90 mins = 9 hours
If you aim for 8 hours, you are likely waking up right in the middle of a deep sleep cycle (causing "Sleep Inertia" or grogginess). Waking up after 7.5 hours often feels better than waking up after 8.
Signs You Are Getting Enough (Regardless of the Number)
Ignore the clock. Look at your body.
- Do you fall asleep within 15-20 minutes?
- Do you wake up without an alarm (or easily with one)?
- Do you have steady energy in the afternoon without needing caffeine?
If the answer is yes, your number might be 7 hours. Or 9 hours. Margaret Thatcher slept 4 hours. Albert Einstein slept 10.
Conclusion
Stop stressing about the number 8. Stress raises cortisol, and cortisol kills sleep.
Focus on Sleep Efficiency. Don't stay in bed if you aren't sleeping. Make your sleep dense, rich, and continuous. That is the true metric of a good night's rest.