Your health’s non-negotiable — Dr. Pylin Coaching

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Have you ever woken up feeling extremely groggy or feeling like death for no apparent reason?

(It’s not like you went to an all-night rave the night before…or did you? 😅)

This might be due to your chronotype.

What is a chronotype?

Let’s first define some terms and build up to what a chronotype is.

All humans have internally built-in, genetically dictated biological clocks (made up of specific molecules) that dictate the timing of our circadian rhythm, both how long the rhythms are and their timing.

"Circadian rhythms are physical, mental, and behavioural changes that follow a daily cycle.” In Latin, the root “circa” means “around/approximately” and “diem” means “day”. These rhythms are mostly known as related to the sleep/wake cycle, but it also encompasses things like hormone production, body temperature, cell regeneration, brain wave activity, etc.

There has been debates about how long our internal clocks are, but a rigorous study by Czeisler and team at Harvard has found that "the range for normal, healthy adults of all ages to be...24 hours and 11 minutes ± 16 minutes.” They found that no matter what the people in the study did during the day, or when they went to bed or woke up, their “body temperature and hormones rose and fell on an average of 24 hours and 11 minutes” cycle.

However, despite us all having biological clocks/circadian rhythm that is roughly 24hr+ in its cycle, turns out that not all of our internal clocks are aligned perfectly to the sunrise/sunset times or our work/school schedules, and can impact when you sleep or wake-up (and relatedly, when you are alert vs groggy).

Which brings us to chronotypes. Our chronotype is our “innate tendency to sleep at a particular time during a 24-hour period.” Chronotype is made up of the root “chron” from the Greek word “Khronos” means “time”.

There are 3 main chronotypes

Morning type or “Larks”

These are the people who, say, naturally go to bed around 9pm and wake up around 5am. (We are not counting parents of infants or anyone else who are chronically sleep deprived and PTFO by 8pm). 30% of the population are morning types.

One way to determine if you are this type is to determine your mid-point of sleep. For Larks, their mid-point of sleep occurs before 3:30am.

Evening type or “Owls”

These are those who naturally go to bed around 1am or later, and wake up at 9am or later. 30% of the population are evening types. Their mid-point of sleep is 5:30am or later.

What sucks for the evening types is that, a lot of them think that they have insomnia; they can’t seem to fall asleep around a time they set for themselves like say, 10pm. But this is actually because their genetic makeup doesn’t allow them to!

The middle or "Third Birds”

This term is coined by Daniel Pink in his book "When, the Scientific Secrets of Perfect Timing” (great book by the way, I highly recommend!), this is basically the rest of us who are not extreme morning types (larks) or extreme evening types (owls). This is the majority of us at 40%. I’m one of them!

Mid-point of sleep: between 3:30am-5:30am

(Image from here. Note: I don’t yet feel comfortable endorsing the “personality types” of the Larks vs Owls. So just go with the timing vs “personality” for now 😉) — *(Image from* *here. Note: I don’t yet feel comfortable endorsing the “personality types” of the Larks vs Owls. So just go with the timing vs “personality” for now 😉)*

You can find what type you are using some online assessments for what your Chronotype is at the bottom of this newsletter (below the Today’s Action section. I had to describe one of them in detail, so I didn’t want to put it in the body here for skimmers).

Now for the not so great news:

each of us are hard-wired or genetically predisposed to a certain chronotype.

Basically, you can try all you want to become a certain type, but science is showing that there is literally a gene that determines your type, and you can’t change much, maybe 30 mins max.

The negative implication of this is that, with the way our general society is structured, it seems to favour morning types and the third birds, which makes the evening types really suffer.

Why? Because the quantity of your sleep is NOT the same as the quality of your sleep.

Let’s say you’re an evening type that would naturally get sleepy around 2am and wake up around 10am. But the next day there is a special meeting that requires you to wake up at 8am instead. So you only lost 2 hours or 25% of your sleep (assuming 8hr), right?

Well unfortunately, your brain doesn’t work this way. Your brain goes through 90 minute cycles of deep vs REM sleep, which serves different but both necessary health-maintaining purposes.

The nuance comes in that the first half of the night you have a higher proportion of deep to REM sleep (more deep sleep, less REM sleep), and the 2nd half of the night you have a higher proportion of REM to deep sleep (more REM sleep, less deep sleep).

So because of this and because you woke up earlier, you may actually lose ~80% of REM sleep! (compared to 25% of the “2 hours lost”).

What sucks is, when you lose REM sleep, it majorly impacts your emotional health. People who don’t get enough REM sleep tend to have depression and anxiety. (Note that REM sleep also has physical health benefits, and we know now that there shouldn't be any distinction between physical, emotional, and mental health anyway).

And generally, when people do not sleep/wake according to their chronotype, it has other impacts on their cardio/metabolic output, blood glucose levels, propensity for obesity, amongst other health effects. Heck, it even makes your telomeres shorter, which has implication for early aging.

So if possible, it is highly advised to try to sleep/wake and live/work according to your chronotype for your health and well-being

(For a poignant but also cute story of lovers with different chronotypes, check out this Modern Love Essay/Podcast, The Night Girl Finds a Day Boy or listen to it as a podcast.)

But there are zeitgebers

Zeit…what? It’s a German term meaning “time giver” but also used to label external/environmental cues that can slightly impact our internal clocks. Two main things are light and temperature.

Light

Think about our evolutionary ancestors for a moment. We humans evolved to be active while outside in the sun, and to rest when it gets dark. So we have systems built in us that are very sensitive to light and light exposure, and thus optimal light exposure plays a role in your sleep-wake cycle. And note that human ancestors evolved in Africa around the tropics, and the tropics usually have a very consistent sunrises at 6am and sets at 6pm sunlight cycle.

“When people are exposed to sunlight or very bright artificial light in the morning, their nocturnal melatonin production occurs sooner, and they enter into sleep more easily at night,” writes M. Nathaniel Mead, educator and writer on health. Melatonin is one of the hormones that makes us sleepy as it rises at night. It has a delayed production whereby you have to get light in the morning for melatonin to be released at night, but if you are exposed to bright light at night, it stops production (finicky, I know).

So what you can do is to get light in your eyes in the morning, ideally before noon, meaning you just have to walk around outside (without sunglasses). The longer the sunlight exposure the better, although 2-10 mins is minimum, and not through a window (because it's 50x weaker). Even when it's cloudy that's usually sufficient.

If you can't do this, then you can get those light therapy lamps that emits at least 10,000 lux of light and spend 30 mins in front of it.

Getting light in your eyes around the time you wake up is important for all chronotypes.

This is especially even more important right now for those in the extreme Northern hemisphere, as the sun is rising later and setting earlier (and opposite for the extreme Southern hemisphere).

(Separate but related issue is, due to the light changes and potential light exposure change, it can have impact on your mood due to hormone levels, which may lead to SAD or Seasonal Affect Disorder.)

(Source: https://blog.noisli.com/fight-winter-blues/) — *(Source:* *https://blog.noisli.com/fight-winter-blues/*)

Now on to the opposite, negative effects of light.

The more you expose yourself to light from sunset to bedtime, the more you’re pushing yourself to a later sleepiness time.

When you look at your phone or watch Netflix before bed, that also exposes you to a high level of lux and can mess up your circadian rhythm. Remember earlier regarding bright light stopping melatonin? That’s why you’re not getting sleepy with lots of light exposure in the evening/right before bed.

So the recommendation is stop phone screen scrolling at least 1 hour before bed, dim all your lights, or turn on your phone night light function, download Flux for your laptop, and get blue light glasses/blockers! (Ideally the light dimming would occur in the evenings, not just the one hour before bed).

Another thing to note that, it's not actually the colour of the light per se that's the problem, it's the brightness of the light. "As night approaches, retinal sensitivity goes up, which means it doesn't take much light at night to reset and disrupt the internal circadian clocks of our brain and body," writes Dr. Andrew Huberman, professor of neuroscience at Stanford. So he doesn't necessarily recommend blue light blockers, but "if you like [them] and feel they help you, go for it."

Additionally, you want to sleep in as total darkness as possible. So if there’s still light coming from outside your window, or from all the electronics plugged in your bedroom, they can also disrupt your proper hormone production and affect sleep quality and overall health. Get black-out curtains and minimize or eliminate the number of electronic blinking, visible light in your room as much as possible.

But don’t despair if your sleep cycle has been off or you can’t get outside to get enough sunlight; we can help our biological clocks get back on track with timed exposure to bright light as mentioned above.

(Source: https://poorlydrawnstore.com/products/dont-forget-print) — *(Source:* *https://poorlydrawnstore.com/products/dont-forget-print*)

Temperature

Your core body temperature usually drops 0.56-1.12 degrees Celsius (or 1-2 degrees Fahrenheit) as you sleep.

When your core body temperature is lower, not only do you end up going to sleep earlier, the amount of deep sleep also increases, no matter your chronotype.

What can you do to encourage this?

Take a hot shower (bath, or sauna) before sleep. Ok, this may be confusing because we just said your temperature should lower. The key point for you to know is there is a difference between your CORE vs your PERIPHERAL body temperatures. When you take a hot shower, blood goes to the surface of your skin and places like your hands and feet, and they actually dissipate heat, which makes your CORE body temperature PLUMMET.
Don’t exercise too close to your bedtime because your core body temperature goes up. If you do rigorous exercise, make sure it is at least 2-3 hours before your bedtime.
Make sure your ambient temperature is optimized for sleep. See the ideal sleep temperatures below
Use sleep pads that help regulate your (vs your sleep partner’s) temperature

Ideal ambient sleep temperatures are listed below:

(From the company Casper's blog, which incidentally has been my bed of choice for the past 5 years and counting). — *(From the company Casper's* *blog, which incidentally has been my bed of choice for the past 5 years and counting).*

Final tips

Other tips and insights from Dr. Matt Walker, Sleep Researcher, the Director of the Center for Human Sleep Science, and Professor of Neuroscience and Psychology at UC Berkeley:

Caffeine is in your system for longer than you think.

Turns out the quarter-life of caffeine is 12 hours (how long it takes for caffeine to break down to 1/4 its original strength). “So if you drink a coffee at noon, at midnight a quarter of that caffeine is still in your brain.” It can also take 24-36 hours for it to completely leave your system. He recommend avoiding caffeine after 1pm. #cryinginsideasatealover

Sleeping pills and alcohol don’t actually help you sleep.

They don’t actually put you into “true” sleep states; it just makes you unconscious (“[knocks] out your cortex.”) Basically, you are sedated and not asleep, and thus not reaping the benefits of true sleep (where your brain and other systems get repaired).

You may need to get a divorce…a sleep divorce with your partner.

Because “sleep trumps everything”, Dr. Walker recommends insomniacs to sleep in separate beds from their partners.

The not so secret, “secret” to sleep is regularity.

“If there one piece of advice I would give anyone, it is regularity. If it is the weekend or weekday, even if you’ve had a bad night of sleep, wake up at the same time.”
Not gonna lie, my dad, Dr. Somkiet Chuapetcharasopon, has been dictating this all my life and now as I’m getting older, I am seeing his wisdom. Thanks Dad!

This last one isn't directly from Dr. Walker, but he's mentioned it in some form:

Let's create a more chronotype inclusive work/life environment and No more sleep shaming.

As we just learned, chronotypes are genetically determined, and pretty much impossible to change. So let's stop judging people who sleep in later and go to bed later, and allow for work hours that are inclusive for different chronotypes.

Today's Actions

Comprehensive checklist to optimize your sleep:

Are you getting light of at least 1,000 lux exposure for at least 30 minutes in the morning, without sunglasses? (either with bright sunlight or light therapy lamp) - If not, what will you do differently?

Do you stop consuming caffeine by 1pm? - If not, try this and see if you sleep better.

And if you "crash", try a power nap (no more than 30 mins), try tea instead of coffee, watch what you're eating for lunch, or go take a walk when you know you are likely to feel the crash.

Are you dimming your ambient lighting in the evenings? - If not, start dimming your home light right after dinner.

Do you use Flux on your laptop or phone? Or do you have your laptop and phone set up to automatically turn on the night screen mode features? (less blue light, darker screens) - If not, do this now. Or at least manually dim the brightness of everything you’re using to the darkest it can be.

Do you stop looking at your laptop or phone screen at least 1 hour before your bed time? - If not, what can you do to make this happen?

If you are not doing the 2 points above, do you own blue light blockers/glasses? - If not, you can try it out, but this is optional. But if you do use it, use it in the evening, not all day during the day. A brand recommended by some experts: https://www.swanwicksleep.com/

Are you doing rigorous exercises within 2-3 hours of your bed time? If so, don’t.

Are you taking a hot shower, bath, or sauna before bed? If not, try it out!

Do you regularly go to bed and wake up at the same time everyday? If not, try a few weekends of having the exact same sleep schedule as your weekday during the weekends (unless you were sleep deprived during the week, at least aim for the same bed time on the weekend), and see how you feel the following Monday.

Are you using alcohol or sleeping pills to help you fall asleep? If so, stop. Unless you have a legit medical condition and your doctor has prescribed sleeping pills. But always ask your doctor about the trade off. Just because they're your [whatever] doctor doesn't mean they know the latest research on sleep or the full impact of how the sleeping pill may have other side effects on you.

Do you have black-out curtains or really good eye masks? If not, get them.

Do you have electronic blinking, visible light in your room? If yes, eliminate them or try to get rid of as many as possible (even if you are “asleep” your body can still sense light)

Is your sleeping partner waking you up at night? It seems like a societal taboo to sleep separately, but sleep has SUCH IMPORTANT functions for our health, well-being, and how we treat this partner (our children, friends, colleagues, etc.) during our waking hours that it may be worth it to have good night sleep separately.

Do one of the chronotype assessments below to figure out what type you are.

You can also try to wake up without an alarm clock, and go to bed when you are sleepy (after you do all the points above!) to see what your actual, natural sleep/wake cycle is. Note that this may be hard to do during the work periods, so you may want to experiment during a vacation because you may need a few days to figure out your cycle.

Chronotype Assessments

1) Horne-Ostberg Morning-Eveningness Questionnaire (MEQ)

Easy to use, straight forward online assessment to figure out your chronotype. I recommend you use this one.

2) Munich Chronotype Questionnaire (MCTQ)

This questionnaire fills the gap in the limitations of the MEQ by measuring actual sleep time on weekdays (specific time for work or school) vs free days (sleeping/waking whenever you want). The MCTQ has been found to be more accurate than the MEQ in predicting one’s chronotype.
Paper version only in English and German, for Adults, Children, and Shift-Workers
However, I don’t recommend using this for a layperson, because there are complicated scoring formulas (it’s basic math, but there’s a lot going on) - but if you REALLY need to know and will do the math, you can get the instructions here “MCTQ variables")
“The MCTQ uses MSFsc as a chronotype indicator, with higher MSFsc reflecting stronger eveningness tendency.” "MSFsc is a strong predictor of chronotype." I literally had to a bunch of googling to figure out wtf MSF vs MSFsc meant.
- MSF = mid-sleep on free days
- MSFsc = mid-sleep on free days corrected for sleep debt on weekdays
In simpler terms from Jordan Harbinger’s show notes interview with Daniel Pink (regarding his book "When, the Scientific Secretes of Perfect Timing”, great book as mentoined earlier):

3) The Power of When Chronotype Quiz

This is another popular one that I don't fully recommend.
The reason I like it: don’t you love knowing what type of animal you are? (Lion, Dolphin, Bear, and Wolf…I’m a Bear).
The reason I hate it: he’s confounding chronotype with personality types, and although I haven’t looked thoroughly into research on this, this screams “pseudoscience” to me. So I recommend against it.)

What are you committed to doing to help your sleep and health? Share it with me and your sleep partner!

Until next time, Transcenders!

~Pylin

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P.P.S. I’d love to hear from you! Let me know if you love a topic, don’t like a topic, want to hear about a certain topic. I’m all about learning from others and connecting! Email link below or pylin@drpylin.com