The Weekly Thread: the seasonality of sleep, control light exposure for better sleep, and the resurrection of the exercise trampoline.

A research report on a sleep study published in 2023 titled, Seasonality of human sleep: polysomnographic sleep data of a neuropsychiatric sleep clinic” aimed to better understand the effects our seasons have on our sleep, and determine if there was any seasonality to our sleep. 

In 2019, 292 patients participated in a sleep study where they were advised to sleep as they normally would, including timing, but were not allowed to use alarm clocks, so that study participants could sleep to full length for the sake of properly measuring their overall sleep, and time in key sleep cycles, most notably, Short Wave Sleep (Deep) and REM. 

Study participants were also excluded from using psychotropic sleep agents.

Here’s what they found:

✔️ Total Sleep Time was naturally about 60 minutes longer during winter months than summer months.

✔️ REM Sleep latency was around 25 minutes shorter in fall months versus spring months. 

✔️ REM Sleep was naturally about 30 mins longer in winter months than summer months. 

Takeaways

If you notice it gets harder to get out of bed as the days get shorter and colder, especially in those cold winter months; it appears there is something biological and very real to it, more than just maybe not wanting to get out of a warm, cozy bed. 

The key aspect of this study is that participants were not allowed to use sleep drugs or an alarm clock, and were allowed to sleep until full length, or when they got out of bed feeling fully rested. 

This variable allowed participants to get a full night’s sleep, or whatever was needed, and thus, allowed the researchers to measure any potential effects seasonality had on natural sleep cycles. 

It does appear that you do, in fact, need more sleep during those cold winter months to fully recover, as “Total Sleep Time” was about 60 minutes longer in winter months compared to summer months. 

Most notable during these 60 extra minutes, was seemingly a natural need for about 30 extra minutes of REM sleep, which is the sleep cycle where your brain consolidates memories, learns, and detoxifies. 

Conclusions

If possible, try to get more sleep as the months get colder, especially during the winter months. 

Now, for many of us, that’s a lot easier said than done, so the next best thing is to hack your sleep to get higher quality sleep, which means more time spent in those super important Deep and REM sleep cycles in the time you do sleep. 

And on that note…

Control Light Exposure 


Probably the most critical factor in properly setting your Circadian Rhythm both in the morning and evening, is controlling your exposure to both natural and artificial light. 

Which makes it probably the most important factor in hacking a better quality night’s sleep. 

The key is to control your exposure to natural light by getting as much as possible to start the day, and eliminating as much exposure to artificial light as the evening wanes and your body wants to begin its nighttime endogenous hormone pulse. 

Remember, we did not evolve with artificial light. In fact, it’s only very recently in human history that we’ve had artificial light at our fingertips. 

We used to have no choice but to make natural light exposure upon waking, our first light exposure, and then even at night, lighting a candle, or any kind of flame, is also a natural light wave that is recognized by the eye and brain, and does not cause an excess cortisol response at night when that’s the last thing you want. 

Basically, the human body doesn’t know what to do with artificial light, and it stresses the body and brain out, causing an unnecessary cortisol response. 

This is no way to start your day, nor end your night. 

Let’s Start with the AM 

The key to jump starting your body’s natural Circadian Rhythm is to get natural light exposure as immediately as possible upon waking. 

❌ No scrolling through your phone.

❌ Don’t turn on any light switches. If the sun is up, even if it’s cloudy, there’s enough natural light coming in that you don’t need to flip on any light switches. 

Do you routinely wake up before there’s any natural light? Or have to in those winter months with shorter days?

Keep reading, as I’ve got some cool hacks for you. 

Just get your butt outside, rain, snow, sleet, or shine. 

If you can, get your bare feet in the grass too!

✅ Natural light exposure as your first light exposure of the day will trigger a natural cortisol pulse, whereas artificial light exposure as your first light exposure of the day will cause an artificial cortisol response, not in line with a Circadian Rhythm. 

✅ Drink a glass of water, and if you can, get outside and go for a walk, or do something to get the body moving. Ideally you want natural light exposure immediately upon waking, and at least 30 minutes of natural light before noon. If you can get that minimum of 30 minutes in right away to start the day, even better. 

Eliminating artificial light in the PM

As discussed above, in the evening, your Circadian Rhythm controls a pulse of nighttime hormones that put your body in a natural restful state that prepares you for a quality night of restorative sleep. 

This is usually around 10 pm. 

If you have too much cortisol in your bloodstream still from the day, due to an improperly set morning Circadian Rhythm, and/or excessive stress, your body cannot transition into this nighttime pulse of hormones nearly as well. 

To do this, you want as little cortisol in the bloodstream as you approach that 10 pm hour. Which also means, you definitely don’t want to be doing anything that can cause a cortisol response such as exposing your eyes to artificial light. 

Now, we don’t live in a perfect world, and sometimes we may have work we need to do, or there may be a necessary reason to have your face staring at a screen. What I think is most important is to be cognizant of the effects artificial light has on your sleep quality, and to mitigate it as much, or as early as possible.

Red Light When No Light 

I told you I had some tips and hacks that can help you have more control over artificial light exposure when there’s no natural light. 

If you wake up before the sun rises, whether it’s every now and then, or quite consistently, having your house armed with some lights that have amber incandescent bulbs in them can provide you with enough light to move around and get stuff done without turning on the bright lights, and will also emit a lightwaive that more closely mimics the light of a sunrise, which helps your body more effectively transition from pitch dark to the natural light of the day. 



Using these lights at night is also effective, as it also mimics the light of a sunset, or fire. But, you may also have family who isn’t as accommodating, so you can also throw on a pair of blue light blocking glasses to block artificial, cortisol inducing, blue light waves.


If you get a pair of blue light blockers, I do recommend springing for a quality pair (as with most things), as many of the cheaper brands may use cheap lenses from China that aren’t as effective. 

I personally use Ra Optics, They also sell daytime glasses with lenses that block many of the harmful artificial light we typically get exposed to throughout the day. 

The first thing I do upon waking in the AM after I drink a glass of hydrogen enriched spring water is go outside regardless of conditions or temperature, and jump on a small trampoline.


No joke. 

The actual act of jumping on a trampoline is called “Rebounding”, and its benefits have even been researched by NASA!

So how does this benefit me?

This may sound a little too literal, but “rebounding” jumpstarts your body in a way no other form of movement does, due to the acceleration (jumping up) and deceleration (landing on and the trampoline absorbing your downward movement) of the movement.

These benefits can include:

  • Boosts lymphatic system drainage. (Your lymphatic system is your body’s internal detoxification pathway.)
  • Improved immune system function 
  • Helps you burn more calories 
  • Improves recovery from other exercise
  • Improves oxygen circulation throughout the body


Rebounding is great for you anytime of day, and can be done multiple times per day to keep your metabolism and energy levels high, however, I find it’s best when done right away in the AM upon waking to really get all those systems moving and functioning properly. 

I do about 3 minutes every morning as indicated above. Ideally get outside and do it, as the natural light exposure and change in temperature (whether it’s hot or cold) from the ambient temperature of your house, further helps jumpstart the body, thus compounding the benefits of rebounding.

PRO TIP: If you can, on days with sun, watch the sun as it rises while you rebound. As discussed above, the immediate exposure of natural sunlight for your eyes kickstarts a lot of positive hormonal and endogenous chemical processes in the body that give us more natural energy, boosts metabolism, and helps you sleep better at night by effectively setting your Circadian Rhythm. 

So how do you get started “rebounding”?

  1. Buy a small exercise trampoline just like the ones that were popularized in the 80s (guess they were actually on to something)
  2. Jump on it. 


That’s it. You’re officially “rebounding” in two easy steps. 

I recently got this trampoline from ONETWOFIT on Amazon, and it’s absolutely perfect for use as a “rebounder”. Highly recommend!