Why You Need to Catch Your Sleep Window and What to Do When You Miss It

The next time you're considering staying up late to get more work done or to watch a new film that's just been added to Netflix, you might want to take a moment to think about the things you need to do and the decisions you'll have to make the next day. Decide if you could do it all after having a few beers in the morning.

There are several studies comparing sleep impairment to drunkenness, and one, in particular, found that going 17 to 19 hours without sleep (a typical day for most of us) was the equivalent or worse than having a blood/alcohol concentration of 0.05 percent in your system.


After four days on 5 hours of sleep per night, you're almost the equivalent of being too drunk to drive. Try 6 hours of sleep per night for 14 days, and you're concentration and alertness levels are as low as if you had stayed up an entire night.


So, how do we get a better quality of sleep?

We live in a very cyclic world. We have four seasons, stars have annual patterns, some birds migrate on a yearly basis, and of course, circadian rhythms are essential for most living things, even bacteria.


Humans are no different. Our bodies produce a daily dose of cortisol in the morning to wake us up and at night our melatonin levels rise to put us asleep. We also have ultradian rhythms—rhythms shorter than 24 hours where we experience oscillations in alertness, concentration and physical performance throughout the day.


Unfortunately, nowadays we're either moving so fast or medicating these rhythms with caffeine to the point where we are no longer aware of them. However, if you can act in sync with these rhythms, falling asleep and getting up in the morning can be as smooth and seamless as a rower hitting a good stroke.


What we should strive for, and what our bodies would like us to do, is to fall asleep just a few hours after the sun goes down. This differs depending on where in the world you are but for most people, it's around 10 pm.


Sleep pressure and sleep window

As you're awake throughout the day chemicals build up in your brain and you develop what is known as a 'sleep pressure.' Then, during the night, physiological processes such as melatonin secretion work to set up a 'sleep window.'


If the build-up of sleep pressure and the sleep window are in alignment, you drift off to sleep without a hitch. However, if they are out of sync due to an over intake of caffeine, having a wonky sleep schedule or because you are stimulating yourself with your phone before bed, then you'll miss your chance of falling asleep. After the sleep window closes, usually around 11 pm your body is programmed to give you a second wind of energy, in the form of cortisol, which can keep you awake until as late as 2 am.


Now, if you have the flexibility in your schedule to go to sleep at 2 and wake up at nine that might not sound like such a big deal. But the anticarcinogen and antioxidant melatonin plus the Human Growth Hormone, the 'youth hormone', are secreted in their most potent dosage between 10 pm and 2 am. And the reason we can sleep but still wake up feeling tired is that we missed out on our dose of these hormones.


Resetting your biological clock

An easy way to set yourself up to fall asleep at this time is by resetting your biological clock by getting some sun in the morning between the hours of 6 am and 8 am. Research from the Journal of Clinical Innovations in Neuroscience has found that exposure to sunlight in the morning significantly decreased cortisol levels later in the day. By getting some sunlight when you wake up, you set your cortisol and melatonin to be at optimal levels for getting a good night's sleep, and for falling asleep at the right time.


But there's a caveat here; your body is very good at latching on to whatever rhythm it can, so if for whatever reason your schedule doesn't allow you to go to bed by 10 pm, try and at least came the same bedtime each night. We're a lot more like Pavlov's dogs than we like to think and your body will anchor whatever physiological processes it can to certain times of the day, to your environment and even to objects.


This is why it's imperative to keep the phone and the laptop out of bed. If you like watching TV or playing games at night that's fine, but you don't want your brain saying, “Oh, we're in bed. It must be time to play flappy bird.”


It's all in the mind

If you can train your mind to understand that 10 pm is the time for sleep and that your bed is the place for sleep and only sleep, it will do the work for you. Then, if you can establish a pre-sleep routine that always happens in the same sequence, take a bath, make some herbal tea, read a book (or whatever), that will then create more anchors associated with sleep and it will be even easier to pass out quickly after your head hits the pillow.


Your brain is very good at automating processes like this. Taking advantage of this automatic processing and establishing simple and positive associations like 'bed' is only for 'sleep' is called Cognitive Behaviour Therapy (CBTI) and it's used as a method for treating insomnia. In fact, CBTI can be so successful in the treatment of sleep disorders that in the short run it has an impact equal to treatment with medication, but in the long term is the clear winner.

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