natural born night owl, wake up exhausted, can't sleep

The Surprising Cost of Being a Night Owl

Most of what we hear about getting enough sleep relates to how LONG you sleep, but a significant factor in getting the rest you need is WHEN you sleep.

The first time I heard the saying “an hour before midnight is worth two hours after” I didn’t know what to make of it. But it turns out there’s good science behind it.

The Importance of Deep Sleep

Sleep researchers have identified two types of sleep that we have each night: REM sleep (Rapid Eye Movement associated with dreaming) and non-REM. There are three stages of non-REM sleep.

We don’t need to go into a lot of detail. What’s important to understand is that out of the three stages of non-REM sleep, it is only in Deep Sleep, that our body rebuilds, restores and repairs itself.

So even if you get eight hours of sleep, if something interferes with your stage 3 Deep Sleep then you won’t be able to rejuvenate and heal.

What Could Interfere with Deep Sleep?

When you fall asleep, you go through a cycle of approximately  90-minutes of non-REM sleep followed by REM sleep. So you cycle through Stage 1, Stage 2, Deep Sleep, then REM sleep every hour and a half.

But the ratio of non-REM to REM sleep changes across the night. In the early part of the night (11pm – 3am), the majority of those cycles are composed of Deep Sleep (stages 3) and very little REM sleep. The early part of the night does NOT refer to the first four hours after you go to bed but specifically the hours up to about 3am. Our bodies are hard-wired to get Deep Sleep between during that time.

In the second half of the night (3am – 7am) this balance changes, so that the 90-minute cycles are comprised of more REM sleep (the stage associated with dreaming) as well as a lighter form of non-REM sleep (stage 2).

So if you’re not going to bed till 2am, or you’re tossing and turning till 3am, you will be running at a deficit – even if you sleep 8 hours.

Timing is everything.

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Dr. Marina Rose uses Chiropractic care and Functional Nutrition to help people in and around San Jose, CA to get the good quality sleep they need to rest, rebuild and repair.


  • Nancy Monson

    Reply Reply May 19, 2015

    GREAT article Dr. Rose!

    I wondered about this too as in Ayurveda, they say to be asleep by 10pm to get the most restorative sleep. This explains why!

    Thank you!

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