One thing in common between ALL Animals, including US Humans, is that we all sleep. It is an integral
part of your life from the day you are born up until the day you die. And if something happens
every single day without exception, we can all agree it must be important.
We are aware that getting a good night's sleep on a consistent basis is essential. We’ve been
bombarded with warnings that not sleeping well, at the right times, or long enough is detrimental
to our mental and physical state, as it can impact all sorts of subsystems in our body,
including cardiovascular, metabolic, learning, dementia, depression and so on.
But I’m sure that very few of you are getting those 7-9 hours of quality sleep,
waking up energized and alert, ready to attack the day without losing energy or focus.
And today we will learn some tools and strategies you can use
to fall asleep faster, sleep better and wake up feeling rested.
So, Sleep is this strange period of our lives, when we are unconscious
and in the most part unable to be impacted by outside sensory experiences. It is a tremendously
important period because it resets the ability to be attentive, alert, and emotionally stable
during the day. However sleep is just one side of the coin, and it's closely related to wakefulness.
The actions we take while we are awake determines when we fall asleep, how quickly we fall asleep,
whether or not we stay asleep, and how rested we feel the following morning.
WHY DO WE SLEEP
Well, we all know that the longer you stay awake, the sleepier you get. The reason for this is
a molecule found in your brain and body called Adenosine. It is a chemical compound that builds
up the longer you are awake. So if you slept for a good 8 or 9 hours, the levels of Adenosine in
your body will be low. But as you go about your day Adenosine slowly builds up in your system,
which makes you sleepy, and this partly is the reason why we want to sleep. Although, if you ever
pulled an all-nighter, and you stayed up until the morning you’ve noticed an increase in energy and
alertness, even though adenosine was building up the whole night. That is because there is another
more powerful force that governs our sleep habits, and it’s a so-called Circadian Force.
Inside EVERY animal's brain, including your brain and my brain, there is a biological clock
that tells the body when to sleep, wake, eat, etc. And if you want to get the benefits of
regular sleep and wake up feeling rested, your job is to set this clock to work in your favor.
HOW DOES ONE CYCLE OF THIS CLOCK LOOK LIKE
A typical 24-hour circadian cycle would start early in the morning sometime after sunrise,
the levels of adenosine in your body are low (for reasons now you’re familiar with),
and your nervous system releases a hormone called Cortisol that signals the body to start tensing
your muscles, raise your heart rate and start waking up. You might heard of Cortisol as a
stress hormone, but if it's released early in the morning it is actually healthy - because
it wakes you up and makes you able to move and wanting to move for work, school, exercise, etc.
However this stress hormone also serves another purpose, this pulse of Cortisol in the morning
that wakes you up is what STARTS the circadian clock. After the release of cortisol in the body,
a timer is set, and in about 12-14 hours the body secrets another hormone which in turn
makes you sleepy. This hormone is called Melatonin and its secreted from the pineal gland.
These wakefulness and sleepiness signals are what constitute the circadian rhythm. They
happen in our body every single day. A pulse of cortisol which wakes you up, and 12-14 hours later
a release of melatonin which puts you to sleep. This rhythm is endogenous, which means it happens
regardless of any external input. So if you were in complete darkness like a cave, this
cycle would still happen once every 24 hours, but it will happen somewhat later and later each day.
Whereas under normal conditions EXTERNAL inputs can START the mechanisms at regular times.
And this is the keyword REGULAR TIMES. There are a number of studies which point out,
that we NEED to set these rhythms right in order to prevent negative effects on our cardiovascular
and metabolic health, trouble learning, focusing, anxiety, depression and the list goes on.
SO HOW DO YOU START THIS CLOCK AT THE RIGHT TIME
Different things can affect this rhythm, but one particular sensory event that is a
thousand times more effective than any other is LIGHT and more specifically SUNLIGHT.
So what happens when you wake up? you open your eyes, and light is perceived by your retinas,
there, a so-called retinal ganglion cells, send electrical signals to this central clock
that resides above the roof of your mouth called suprachiasmatic nucleus. And this central clock
has connections to essentially every single cell and organ in your body. So there is a
direct physical connection between the light that enters your eyes and the circadian clock, and
the way you can regulate the clock is by exposing yourself to SUNLIGHT. It is vitally important for
light to be communicated to this central clock in order to time the cortisol and melatonin properly.
Because if we wake up and we are in a dark room, there isn’t enough light to trigger the activation
of these mechanisms. The release of cortisol will be shifted later in the day, followed by the late
release of Melatonin, which can lead to you not being able to fall asleep. We also know that this
shift in cortisol later in the day is a signature of most anxiety and depression disorders. So it
is critically important to get out and get this light properly. Preferably early in the morning,
as close to waking up as possible. Because these retinal ganglion cells, that activate the clock,
respond best when the sun is at a low solar angle or in other words sunrise. But if you cant catch
the sunrise, you should still go out as early as you can, and get this light appropriately.
So how long should you expose yourself to sunlight? Well, if the sky is clear
and you live towards the Equator, 30-60 seconds of sunlight should be sufficient to start this clock.
However, in countries where sunlight is limited, you might need to stay out a little bit longer,
anywhere from 2-10 minutes. And for this exposure, it's crucial for you to be
outside because a study done by a Stanford University professor Jamie Zeitzer states
that viewing the sun through a window, or a car windshield is about 50% percent less effective.
So after you start this clock how do you keep it in check? Well the answer again, is light.
There is a lot of content circulating the internet telling us that Blue light is bad for us, however,
that’s not the case. Blue light can, to some degree, mimic the effect of sunlight, which means
you SHOULD expose yourself to blue light during the day - because it suppresses the release of
melatonin, which as we know was tightly connected with sleepiness. So if you want to be alert and
awake during the day, you should expose yourself, safely, to as much light as possible. However,
during the later period of the day, you need to be careful. Because the LONGER you are awake after
10 12 14 hours, the more sensitive your retinas become, and light in the later stage of the day,
can negatively impact this cycle. So ideally you want MORE light early in the morning and afternoon
and LESS light at the end of the day. But if you HAVE to watch light in the evening and
you cant get around it, you should place the lights lower in your environment.
The cells in your eyes that detect sunlight are placed in the lower portion of your eyes, so they
can detect light sources that come from above - just like the sun. So by placing your artificial
lights at a low angle, using warmer colors, and not using overhead lights, you can avoid improper
activation of these receptors, which is a good thing if you want to be able to fall asleep.
So as you now know you have these internal mechanisms of adenosine and the circadian clock
and they operate 24/7. Your job is to provide them anchor points so your cortisol and melatonin,
and everything else that cascades down the line like metabolism, ability to learn,
sense of alertness, dopamine, serotonin, are timed regularly. It's NOT that important to
be EXACTLY on the minute every single morning, because these systems work, by averaging out
when you see light in your day, but giving them CONSISTENT anchors can really provide
positive benefits and general well being. It can make you fall asleep faster at night,
by letting your body release melatonin at the right times, and also make you
more alert and focused during the day by the healthy release of cortisol in the morning.
So if you want to live optimally, try these changes for a week,
get out and get the sunlight - trigger your circadian clock at the right time.
Use the knowledge you learned from this video to regulate when you wake up and when you fall
asleep, and see how getting a good night's sleep regularly, can affect your life for the better.
I want to thank you guys for watching and feel free to tell me in the comments if you like this
science-based approach more than the other animated videos. Take care and I’ll see you soon.