Hey,
hope you are all doing fine😊
Some of you may have noticed my short story on Instagram about how light and the color of light affects our sleep.
In today’s Issue, I want to go deeper into this topic, explaining how our sleep works and why light affects it.
So let’s get into this ✍🏼
PS: I’ve got a little surprise for you at the end!
Sleep & Wake Cycle:
Our body runs on several internal clocks, called the circadian clocks. Typically they run in a 24-hour repeating rhythm, which is called the circadian rhythm. This rhythm affects almost every part of your body. From cells to organs and tissues. Being out-of-sync with your body clock and rhythm can lead to a higher risk for obesity, cardiovascular disease, diabetes, gastrointestinal problems, neurodegenerative disorders, skin issues, and more. These are all things that are preventable if being healthy.
The central circadian clock is located in our brain and it tells us when it is time for sleep. the others are in organs throughout the body.
These internal clocks are in sync with different cures in the environment. Some of them being light and darkness.
Now if you are exposed to artificial light and/or take caffeine this process gets disrupted by giving your body false wakefulness cues. And also by blocking other mechanisms which we will get to later on.
Sleep Cycle:
Most of you know that our sleep cycle has different stages we go through every time we fall asleep. But what exactly are those stages and what are they doing?
First, when you sleep you cycle through two different phases of sleep. Rapid eye movement (REM) sleep and non-REM sleep which is also called deep sleep or slow wave sleep.
Non-REM sleep:
Stage 1: This stage is the transition between wakefulness and sleep.
Stage 2: here you are finally asleep.
Stage 3: This is a deep sleep or slow-wave sleep. Early in the night is when you spend more time in this stage.
REM sleep: This is the sleep phase where your eyes twitch fast and your brain is active. In REM sleep the measured brain activity is the same as when you are waking. This is also the phase where dreaming usually happens. To prevent you from doing weird things while dreaming your muscles become limp.
In non-REM sleep, your blood pressure and heart rate fall. Also, your parasympathetic system controls your body, which means your heart doesn't work as hard as it does when you are awake.
During REM sleep your sympathetic system is active, which increases your heart rate and blood pressure to the usual levels when you are awake and relaxed.
The Urge to Sleep:
Everyone's body has a natural need for sleep that increases when you have been awake for a long time. All this is controlled by homeostasis, which is the process that keeps your body’s systems continuous.
The urge to sleep is associated with a chemical compound known as adenosine. As you stay awake, the adenosine concentration in your brain gradually increases, indicating a transition toward sleep. Adenosine-blocking substances such as caffeine and certain medications can interfere with this natural process.
→ But how much sleep is actually enough?
Short and simple: 7 to 9 hours a night. This is what experts are recommending to adults. Generally, you can say, the younger you are, the more sleep you need. But it varies a lot. Some may be feeling fresh and ready after 5-6 hours, but that doesn't necessarily mean that your body is well-rested
Sleeping too little adds up over time and that leads to a higher risk of various diseases. So make sure to fix your sleeping schedule and get enough sleep every night.
Adenosine, Melatonin & Cortisol:
Adenosine, melatonin, and cortisol are all important in regulating the sleep-wake cycle, but they work in slightly different ways.
Adenosine is a neurotransmitter that accumulates in the brain throughout the day as you stay awake, signaling the need for sleep. Adenosine promotes the feeling of drowsiness and helps to start sleep.
Melatonin is a hormone produced by the pineal gland in the brain that helps to regulate the sleep-wake cycle. Melatonin production is regulated by the body's internal clock, and it is released in response to darkness. Melatonin promotes sleepiness and helps to regulate the timing and quality of sleep.
Cortisol is a hormone produced by the adrenal gland in response to stress. Cortisol levels are highest in the morning and promote wakefulness and alertness. However, when cortisol levels are always elevated due to chronic stress, it can interfere with the production of melatonin, making it more difficult to fall asleep at night. High levels of cortisol can also inhibit the effects of adenosine, making it harder to feel sleepy even as adenosine levels rise.
Overall, adenosine, melatonin, and cortisol all play important roles in regulating the sleep-wake cycle, but they have different mechanisms and functions. Adenosine helps to initiate sleep, melatonin helps to regulate the timing and quality of sleep, and cortisol helps to promote wakefulness and alertness in the morning. The interplay between these hormones is complex and essential for maintaining healthy sleep patterns.
The graphic above illustrates the build-up of adenosine and melatonin in our bodies. Adenosine builds up throughout the day, leading to a feeling of sleepiness. On the other hand, melatonin is released in response to darkness and helps regulate the quality and duration of our sleep.
Effects of Light:
As we now know, melatonin is a hormone that helps to regulate the sleep-wake cycle and is produced by the pineal gland.
However, exposure to artificial light at night, especially blue light from phones and laptops, can interfere with the body's natural release of melatonin. This is because blue light can suppress the production of melatonin and make it harder to fall asleep at night.
This blue light can interfere with the body's internal clock, which relies on the natural 24-hour cycle of light and darkness to regulate the release of these hormones. When the body is exposed to bright light, especially blue light, in the evening, it can disrupt the natural release of melatonin and make it harder to feel sleepy and fall asleep.
To minimize the impact of artificial light on melatonin production, it's important to limit exposure to blue light at night, especially in the hours leading up to bedtime. This can help to maintain healthy sleep patterns and promote restful sleep.
If you are unable to limit exposure to blue light due to work or other reasons, you might wanna invest in a pair of blue light blockers and light bulbs that you can switch to red in the evening. Why red? Red light doesn’t suppress the body's melatonin production. Blue light does!
Why is a Routine Important?
We already know that having a consistent and healthy routine is insanely important to maintain a strong performance during the day. But why exactly should you have a consistent sleeping routine?
What we now already know is that the neurotransmitter Adenosine builds up during the day and as it builds up it makes us more and more sleepy. Now if we create a consistent routine Adenosine will regularly peak at the same time and make us feel sleepy and ready for bed. Which is great. And then after we had enough sleep our Adenosine levels will be low enough to wake up naturally while also feeling well-rested.
Healthy Sleep Routine Outline:
Set your alarm for the same time every day. (Don’t break this routine on weekends. Wake up at the same time every day.)
Stop using your phone 1 hour before bed. (At least avoid using social media close before bedtime. Give your brain some rest.)
Expose yourself to direct sunlight first thing in the morning. (Signals our circadian clock that it’s daytime.)
Switch phone and laptop for kindle or a paper book. (Avoid any blue light that you can. Wearing blue light-blocking glasses also helps.)
Keep your room cold. (Our bodies need a drop in temperature of 1-3°C to fall asleep and stay asleep effectively. 16-19°C seems to be the best temperature for most people.)
I hope you liked this short dive into the factors for good sleep and which mechanisms in the body are working. I also hope that you learned something new!
Try out these 5 tips and let me know if you noticed any improvements 😊
But I've also got some exciting news for you. I'm giving away three pairs of blue light-blocking glasses to three lucky subscribers of my email newsletter.
These glasses are amazing for protecting your eyes from the harmful effects of blue light and also your melatonin production. Plus, they look pretty cool too!
To enter the giveaway, just subscribe to my email newsletter by the 31st of March 2023. Easy, right?
Not only will you have a chance to win the glasses, but you'll also get access to exclusive content, special offers, and updates on my latest projects and initiatives.
Thanks for being a part of this amazing community. I really appreciate your support
Cheers,
Maximilian
🔗 The Link Lounge
A collection of links to stuff I think is worth sharing.
www.nhlbi.nih.gov/health/sleep - how sleep works!
Gumroad - some of my digital products
Visions Of Wellness - some more of my digital products
Twitter - writing about no-code. content creation and productivity
www.buymeacoffee.com/warum - you can fund my coffee addiction here :)