The Way You Think About Sleep Is Wrong

Optimize sleep quality, not quantity. Here’s how.

Thomas Smith
Published in
8 min readOct 4, 2021


Photo: Matheus Vinicius/Unsplash

When most people think about sleep, they treat it like a simple subtraction problem. “I went to bed at 10 p.m. and woke up at 6 a.m.,” the normal thinking goes, “Eight hours passed between my bedtime and wake time, so that means I got eight hours of sleep! I’m solid!”

Unfortunately, this isn’t how sleep actually works. And if you’re thinking about sleep in this way, it might be why you’re “sleeping” for the recommended seven to eight hours per night and still waking up exhausted each morning.

Why? Treating sleep like a subtraction problem focuses only on sleep quantity. It totally ignores sleep quality. If you spent eight hours in bed but you got up twice to use the bathroom, spent an hour tossing and turning, and spent zero time in restorative sleep stages, you didn’t really get eight hours of good sleep. It was probably more like four to five.

In contrast, if I spent six hours in bed but my sleep quality was excellent, I logged way more valuable sleep than you. I’ll have spent less time on sleep — and will appear to have underslept, relative to official recommendations which often look only at sleep quantity. Yet I’ll wake up feeling more refreshed and restored.

Sleep efficiency is the percentage of time you spend actually sleeping at night, versus lying awake in bed, getting up to have a snack or use the restroom, etc.

The higher your sleep efficiency, the less time you have to spend in bed each night in order to feel rested the next day. Sleep efficiency of 85% of higher is considered good.

Ready to enhance your sleep efficiency? Here’s how to stop obsessing about sleep quantity and start thinking about sleep quality.

Sleep when you’re sleepy

This might sound obvious. But as with the “obvious" advice “eat only when you’re hungry,” it’s something many of us struggle with.

Suppose that you’re concerned about getting too little sleep. You might try to get to bed earlier — before you actually feel tired — because you feel like you should be sleeping more, and you think having an earlier bedtime automatically means you’ll get more…