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Do you ever have trouble sleeping?
Not to the level of insomnia, which is a different kettle of fish altogether. I'm talking about those of you (...or us) who believe that they are under-slept, or those who have trouble getting to sleep, or staying asleep throughout the night.
Image: @lizfosslien (Twitter)
Sound like you?
Chances are that this slipper would fit most people. In the Phillips Global Sleep Survey in 2019, 62% of adults worldwide reported that they don't get as much sleep as they'd like, and 67% reported that their sleep is interrupted at least once per night.
So, worldwide we have 2 out of every 3 people reporting some form of sleep disturbance - but why is this a problem?
Well, first and foremost, high-quality sleep is critical! It is the foundation of our physical health, our cognitive health, and our overall performance in general.
Luckily there are some simple and cost-free behavioural changes that we can incorporate into our daily routines that - supported by rigorous & high-quality science - have been shown to significantly improve the control of our circadian rhythms (sleep-wake cycle) and, in turn, our ability to feel sleepy & wakeful at appropriate times.
The levers that influence our sleep-wake cycle include:
Temperature
Light/ Dark
Food
Exercise
Caffeine
Supplements
Digital Tools
To keep it simple & implementable I will primarily focus on Temperature & Light/Darkness exposure.
Today, the focus is Temperature, and how we can best leverage this to increase our wakefulness and sleepiness at time-appropriate moments in our daily cycle.
Let's start with the morning, shall we:
Temperature
The Start of your Day
Now, you might be thinking: I thought this was supposed to be about sleep? And indeed it is, but it is important to first understand that setting your sleep cycle is a whole-day process. What we do in the morning, afternoon & evening primes our body for certain states. It's all part of the big picture.
When you boil it right down, our body temperature - or changes in our body temperature, more aptly put - is the key process that allows us to both fall asleep and wake up.
Let's consider that you're asleep. Maybe your alarm is set for 7:00 a.m. and your internal body clock (which is typically pretty accurate) hazards a guess that the time is now 5:00am. Two hours before your scheduled wake time.
At this point, your body temperature begins to change. In the two hours before we wake up...
our body temperature begins to rise to the tune of 1 -3 degrees celsius.
This triggers our body to wake up, and begins a cascade of internal processes that serve to get the engine started, so to speak.
This increase in temperature and subsequent waking is accompanied by the release of the hormone Cortisol. If you're a bit of a physiology buff you might be familiar with Cortisol. It actually gets a bit of a bad wrap out there due to, in bad cases, the negative effects associated with its chronic presence throughout the day.
But Cortisol is extremely important for us in the morning. When elevated at the right time, being first thing in the morning, cortisol enhances our immune system, our metabolism, our ability to focus and our ability to move.
It basically kick-starts your day.
But this rise in body temperature can, for some folks, take a while, which in turn slows the release of cortisol and, as a consequence, we feel less wakeful in the morning.
So how do we leverage this?
You probably already guessed it - we need to help to raise our body temperature.
Two simple, practical & implementable habits that will significantly help this process are:
1. Morning Exercise
Now this doesn't have to be a full-blown, high intensity workout, although that does bring some nice additional benefits. No, simply moving your body, to the tune of a nice morning walk, several minutes of yoga/ stretching, or a light jog is sufficient to raise your body temperature & kick-start these juicy internal processes.
2. Cold exposure
This one might seem a bit counterintuitive - cooling down my body is the exact opposite of what we want, right?
Not in this instance. In fact, the body has a natural compensatory reaction to extreme temperature exposures.
Expose me to cold - I'm going to heat myself up
Expose me to heat - I'm going to cool myself down
It's pretty good like that.
This cold exposure will trigger a release of our old friends adrenaline & dopamine (all good stuff) and cause an increase in our core body temperature.
The End of your Day
Naturally, to fall asleep we need to reverse the process.
To fall asleep, our bodies must cool down 1 - 3 degrees celsius.
This should begin to occur naturally in the evening if your circadian rhythm has been set appropriately. To help to promote this, temperature exposure is also a great tool.
1. Heat Exposure
exposing yourself to heat (hot bath, shower, sauna) will cause a compensatory drop in temperature & will begin the it's-probably-time-to-sleep-soon processes.
Furthermore on this point, if you are someone who enjoys exercising in the late afternoon or evening this will naturally increase your body temperature. To compensate for this, heat exposure following exercise is a good way to step that body temperature increase to allow the sleep processes to occur time-appropriately.
Key Take Aways:
1. as early as feasible after waking (within the first 3hr is best), try to increase your body temperature by engaging in movement and/or cold exposure. It will prime your body for daytime wakefulness & nighttime sleepiness.
2. In the few hours before you go to bed, assist your body's natural cooling process by exposing yourself to heat (shower, bath, sauna)
In the next instalment I will circle back to light/dark exposure and how this can be leveraged to improve our wakefulness & sleepiness in time-appropriate moments throughout the day.
Slaap lekker
Cover Image: @lizfosslien (twitter)
The primary inspiration for the content in this blog post has been the following podcast by Dr. Andrew Huberman from the Huberman Lab. If you're interested in additional in-depth information then the podcast can be accessed using the link below:
https://open.spotify.com/episode/3TxjF2mZy9S9I9GL5eZ8sq?si=5cfc889428a5420b