MVP Part IV: Optimizing Sleep
Hello!
Today is part 4 of 5 of the Minimum Viable Practice series. The goal of this series is to establish a baseline practice for those who want to get serious about their health and longevity.
Part one can be found here: MVP Part I: Dumb Ways to Die
Part two can be found here: MVP Part II: Optimizing Intake
Part three can be found here: MVP Part III: Optimizing Movement
TL;DR: Sleep ~7-8 hours per night. Wake up/go to bed at the same time every day. Get a good mattress. Sleep alone in a cold, dark, quiet, well-ventilated room. Sleep on your back or side. Exercise. Don’t ingest stimulants, alcohol or large meals before bed.
"Sleep is a reward for some, a punishment for others. For all, it is a sanction.”
-Comte de Lautreamont
You spend a third of your life asleep. 25 years. Yet most of us spend little time thinking about this part of our lives. Historically, we have measured sleep solely by duration. With the advent of wearables and more accurate sleep sensors, this is changing. We are now seeing, largely through the way of self-experimentation, how sleep quality affects our daily lives. New tools offering insights such as the duration of different sleep stages. We have started to evolve the conversation about what constitutes a good night’s sleep.
We still have a long way to go. These tools aren’t very accurate, and just because we can measure something, doesn’t mean we fully understand it. My own approach to sleep is informed from a combination of anecdotal experience and scientific research. With genetic testing in its infancy and areas of sleep research still hazy, I suspect your approach will be similar.
When attempting to optimize sleep, I look at the following:
Duration - How long are my sleeping sessions?
Frequency - How often in a 24-hour period am I sleeping?
Timing - When in a 24-hour period am I sleeping?
Quality - How well am I sleeping during my sleeping sessions?
Polyphasic sleep (frequency) and aligning your circadian rhythm (timing) are important topics for another time. The challenges facing night-shift workers and night owls warrant a dedicated write-up. For our purposes let’s assume you are a monophasic sleeper with a normal sleep schedule. Our focus will be on duration and quality. In order to change these metrics, we'll need to tweak a few variables:
Bedtime/Waketime
Light
Location - e.g. Mattress, futon, etc.
Position
Intake - Food/Supplements
Exercise
Temperature
Sound
Air Quality
These variables are intentionally ordered. I consider bedtime when you get up, light exposure, and sleeping location to be a top priority. Before we dive into these variables, let’s first explore the subject of main concern: How long should I be sleeping?
Sleep Duration
“The amount of sleep required by the average person is about half an hour more.”
- Evan Esar
Average sleep duration and longevity have an interesting relationship. Particularly because one of our goals with increasing our lifespan is to increase the number of meaningful, pain-free hours in our lifetime. Getting more sleep has the potential to be counter to that goal.
For instance, let’s look at the cost of sleeping 9 hours per night versus 8 hours per night. Sleeping one less hour per night would give you 365 more hours per year or 2.08 years of waking hours over 50 years. This means if sleeping 8 hrs vs 9 hrs has no effect on your longevity, you will add the equivalent of 3.13 years to your life**.
So, the question becomes is sleeping nine hours per day healthier than sleeping eight? It looks like no. In fact, it might even be worse for you.*[1][2][3].
Figure 1: The dose-response analysis between nighttime sleep duration and risk of all-cause mortality.
*Red lines are all my own. I was first made aware of this data from reading Alexey Guzey’s analysis of Matthew Walker’s Why We Sleep.
**We divide 2.08 by 0.66 to get “normal days” since in this case, we are asleep for 8 hours
It’s important to keep in mind that the science is far from settled (it never is). A huge contributor to the U-shaped association is likely “that short and long sleep duration might be just markers of poor health status rather than independent predictors”. When taking into account the limitations of observational studies and other studies on sleep duration, I remain skeptical that sleeping 5 hours is as healthy as 8.
Even so, clearly more is not always better. It looks like there's a sweet spot for sleep. Personally, I feel the best at around 7.5 hours of sleep. There's a little wiggle room, but for me, 6 hours is too little and 9 hours is too much. The CDC’s recommendations are a good starting point when determining your own “sweet spot”. The point is don't stress too much about getting in exactly 8 hours every night. Everyone’s different, it will likely take some intentionality and self-experimentation to dial in on what works for you.
Sleep Quality
Anyone who has had a poor night of sleep knows the acute effects of poor sleep quality. Interrupted sleep impairs memory in mice, affects their cardiovascular health, and possibly contributes to Alzheimer’s disease risk. Fortunately, we have a few variables we can change to achieve healthy, sustained sleep.
Consistent Bedtime and Waketime
Bedtimes aren’t just for kids anymore. The CDC’s first tip for better sleep: Go to bed at the same time each night and get up at the same time each morning, including on the weekends. Numerous studies find improved mood in children with bedtime routines. One study found that Greater bed- and wake-time variability is associated with less healthy lifestyle behaviors. Greater consistency in sleep timing may contribute to (or be reflective of) healthier lifestyle choices.
If it's not possible to be consistent with bedtime, at least try to get up at the same time every morning, taking a nap during the day if you must. “Catching up” on sleep doesn’t appear to be very effective. "Sleep isn’t like the bank, you can’t accumulate sleep debt during the week and sleep it off on the weekends”. Remaining as consistent as possible with your schedule will be the most beneficial in the long run.
Light
You have likely heard that you should limit the use of TVs, computers, and smartphones before bed. Twitter gets you riled up and the blue light from your feed is messing with your melatonin and circadian rhythm. Keep your devices out of the bedroom. Get an old school alarm clock. Your bedroom should be for sleeping. It’s not an office or a brunch stop (who wants syrup in their sheets?). In addition, limit your use of electronics 2-3 hours before bed. Consider enabling a program to change the color temperature of your screen (I use f.lux for my mac) or using blue light blocking glasses.
When you do actually make it to bed, ensure your room is completely dark (reference). Even dim light can have an impact on sleep quality. Get as obsessive as you want here. I have light-blocking curtains and use electrical tape to cover any other small lights. If you're scared of the dark consider a night light with a red wavelength, which is most conducive to sleep.
Location
Where you sleep is very important. Optimally, it’s alone in a dark room with a supportive mattress. The optimum type of mattress is still up for debate, but medium firmness is best for most people. Think Goldilocks, not too firm and not too soft. Sleeping alone is also a hang-up for most people. If a sleep divorce is not healthy for your relationship, consider alternative strategies. One setup is a king bed with a memory foam divider down the middle. Another is 2 Twin XL mattresses pushed together, allowing the couple to be close but each has their own space.
Position
Intake
Avoid large meals, stimulants, and alcohol before bedtime. Your dinner should be 2-3 hours before you hit the sack to allow for gastric emptying. If you do consume alcohol at dinner, try to limit yourself to one drink. Alcohol may help you fall asleep quicker, but your quality will suffer.
I don’t usually take supplements before bed. When I do it’s usually melatonin and/or magnesium. I take a really low dose of melatonin (usually 0.3 - 1 mg) and it usually knocks me out. I will also use melatonin when I travel to treat jet lag. When I take magnesium I usually take it in powder form (dosage varies). There is evidence that magnesium can improve sleep quality and even treat insomnia.
Exercise
If you read MVP: Part III, you probably don’t need another reason to be moving every day. Here’s one anyway: you’ll sleep better.
Temperature
Your bedroom should be cool. Around 60-65 Fahrenheit. The data isn’t super clear on this topic but anecdotally I find a low-temp environment makes it far easier to enter and sustain sleep. If cooling bills are a concern, consider a bed fan or a cooling pad.
Sound
Keep your bedroom quiet. I consider both sound isolation and sound masking. For isolation, you are likely limited by your current layout and wall construction. Improvements can be made by adding heavy curtains or a soundproofing door pad. For sound masking, I use a white noise machine. The destructive frequency eliminates noisy neighbors or road noise in a busy city. For the worst cases, you can turn up the white noise and add foam earplugs for a blissful night of sleep in even the noisiest environments.
Air Quality
Air quality is often overlooked when optimizing indoor environments. Poor air quality is low on our priority list even though the effect it has on our brain can be substantial. Air pollution and high CO2 levels may cause poor sleep, poor cognition the next day and even increase the risk of sleep apnea.
If possible increase ventilation to the room by using vents or opening a window. It may also be beneficial to set up an air purifier next to your bed to decrease the level of dust and other allergens that may affect your sleep.
Putting it all together
Usually what prevents us from getting the sleep we want is not lack of knowledge or understanding. We know what’s good for us but we continually engage in behaviors we want to avoid. We trade our future for the present and end up falling asleep with a bag of sour skittles and our MacBook Air playing Netflix. Connect your future to the present. Recognize we always get to the future from the present, it’s the only way there.
Ask yourself, what do I want my sleep to look like a year from now? Write out a path to get there. Building habits is hard work, but with a bit of persistence, you’ll be falling asleep faster, sleeping deeper, and waking up refreshed and ready for your day.