Sleep is one of those fundamental parts of our lives that we generally don’t give enough
thought to and care for. Getting higher quality sleep can leave us feeling recharged and rejuvenated,
ready to tackle our day with a built up reserve of energy. But perhaps understanding how sleep
works can help us learn what we might need to do to utilize it to our advantage.
There are two basic concepts that form the basis for our sleepiness at night and our
alertness during the day. The first is sleep pressure. From the time we wake up in the
morning, our brain builds up a chemical known as adenosine. Over the course of the day,
adenosine accumulates and builds our sleep pressure, thus making us feel sleepy towards
the end of the day. When we sleep, our brain removes all of that adenosine and results
in our feeling alert and refreshed when we wake up.
The second concept is the Circadian rhythm or our 24 hour sleep cycle. It’s often plotted
out as a wave in a graph. As it rises, our body is driven to be awake and active. As
it drops, we begin to lose energy and want to sleep. The Circadian Rhythm is controlled
by a center in our brain known as the Suprachiasmatic Nucleus which communicates signals to our
brain and body that cause us to either feel awake or sleep. It does this through the use
of a chemical called Melatonin which spreads through our body as our circadian rhythm swings
downwards. One of the triggers for the Suprachiasmatic Nucleus to release melatonin throughout our
body is darkness that we absorb through our eyes, which is good sleep is often aided by
dimly lit environments and the setting of the sun.
If you think about the times that you feel sleepy at work or in an indoor setting, aside
from the fact that your work might be boring you, it’s quite possible that your eyes
are not receiving a strong enough source of light from the outside that can help put a
stop on the release of melatonin in your system during the day.
Now, having talked about the circadian rhythm, how much sleep do we actually need? Well several
scientific organizations recommend an average of 7-9 hours for most adults and there’s
a lot of variability within that range with some people needing less and some needing
more. What is much more interesting is that we are often divided into being either a morning
person or a night person. This is known as your chronotype and much to your surprise,
is not actually something you can choose to be. It’s actually entirely genetic. Perhaps
if you’re a morning person and like to get a bunch of stuff done early, it’s quite
likely that one or both of your parents may have been morning people since this is strongly
genetically inherited. So your chronotype is what determines where the peaks of your
circadian rhythm lie and where you feel the most energized and productive. And so the
next time you feel like you aren’t finding your surges of energy early in the day, it
might be worth examining whether your current sleep schedule is coinciding with your genetically
inherited biological chronotype.
There are different stages of sleep that serve different purposes for our cognitive sharpness
and ability to learn and process. These two stages are Non REM or Non-Rapid Eye Movement
Sleep and REM or Rapid Eye Movement Sleep. These two types of sleep often occur throughout
our sleep and sort of compete for space in our brain at any given time.
During the various stages of Non REM Sleep, we are transitioning from a state of being
awake to being asleep, with our body temperature and heart rate fluctuating. Once we enter
REM sleep, we may begin dreaming and fall into a deeper slumber.
It’s been learnt that during deeper stages of Non REM Sleeps, we essentially store and
solidify information that we have gathered during the day so that it can be recalled
over a longer period of time.
REM sleep is very different from Non-REM sleep, with our brain activity and brain wave activity
cycling much faster compared to Non-REM sleep. What it does is it associates our newly learnt
information and associates it with our knowledge reserves that we already have stored in our
brains. Essentially integration and association with existing memories. So what this means
is, it can often help us become much more creative when it comes to solving problems
that we previously viewed as difficult or unsolvable because of the addition of that
new information. Studies have shown that through our dreaming, our brain tests out connections
between the new information and relate them to our memory banks.
So what steps can you take to improve the quality of your sleep?
One of the best tips for improving the quality of your sleep is regularity. No matter whether
it’s the weekday or the weekend. This is due to our 24 Hour Circadian Rhythm which
is our body clock [Image in How to Sleep Better] and it expects regularity and thrives under
that. This regularity gives our brains signals to optimize itself for higher quality sleep
that yield all the benefits that I’ve mentioned earlier.
Another way is to incorporate some kind of wind down routine. Many people like to take
a bath before bed, some others like to meditate, some like to read a book. These practices
serve as a wind down routine that gets you in the groove to shut down for the day. One
of the things I like to do is write down all of my concerns or to-do items because it helps
me externalize all my concerns onto a paper instead of bottling them in and stressing
myself out internally. Kind of serving as a means of catharsis.
The temperature in your room also matters so try to keep it cool. It’s always easier
to sleep in a room that is cooler because your brain and body needs to drop its temperature
for you to fall asleep and to stay asleep.
Dimming the lights in your room around the evening time sends signals to your brain of
darkness in order to release melatonin and help prepare you for falling asleep. This
is why you often hear experts recommending you not to use your phone before bed. It’s
essentially because of the light that the screen is emitting, so at any point, if you
feel like you need to be using a screen before bedtime, dim down your screen and limit the
amount of light that enters your eyes.
Finally, I’m generally not much of a caffeine drinker but caffeine has been shown to impact
the quality of your sleep as well. This is because it has a half life of about 5-6 hours,
which means that 50% of the caffeine that you have is still circulating in your system
5-6 hours after you have it, and 25% of it can be lingering 10-12 hours after having
it. The issue with this is that even though you might be able to fall asleep and stay
asleep, caffeine can prevent you from reaching deeper Non-Rem sleep, which can result in
you waking up the next day not feeling as refreshed and restored, not to mention all
the benefits the deep sleep has on our cognitive function that I mentioned earlier. Each of
us does have a different sensitivity to caffeine but this is simply information that is helpful
to know in order to make better choices with regard to the timing of your caffeine intake
in order to improve the quality of your sleep.
Everything in this video has been discussed by Matthew Walker in his book Why We Sleep
and his Masterclass. If you’d like to know about sleep science and how you can use sleep
to your advantage, I’ve left a link to his book in the description down below. As always,
drop a like on this video if you found it helpful. Also subscribe and hit that notification
bell so you don’t miss any of my weekly uploads. Catch you next time. Bye.