12 Simple Rules to Optimize Your Sleep
12 Simple Rules to Optimize Your Sleep
Science-backed practices to improve physical and cognitive performance and boost your health.
The 12 Sleep Commandments
Rule 1: Finish eating 3 hours before bed.
Rule 2: Do not exercise within 2 hours of bed.
Rule 3: Set the thermostat to 18-20℃ (65-68℉).
Rule 4: Take a hot shower (or sauna) before bed.
Rule 5: Design a nighttime routine that involves one of these practices: relaxing body movements, meditation, and journaling.
Rule 6: Switch off most of the lights in your house and avoid blue light 90 minutes before bed.
Rule 7: Remove all clocks from your bedroom. This includes electronic devices – charge them in a different room.
Rule 8: Go to bed and wake up at the same time each day.
Rule 9: Calculate your sleep efficiency to align your sleep opportunity with desired sleep duration (7-9 hours per night).
Rule 10: Don’t lie in bed awake for long. Get out of bed, sit in dim light, and read a book. Return to bed when you’re sleepy.
Rule 11: View sunlight outdoors within 30-60 minutes of rising and again in the evening prior to sunset.
Rule 12: Halt caffeine consumption 8-14 hours before your bedtime.
The Goal
The target outcome of implementing these rules is to reduce the number of times we wake up through the night (continuity) and to ensure we have enough deep sleep (depth). These are two important factors that would otherwise seem out of our control. It’s equally critical to pay attention to the number of hours we sleep each night (duration) and the time we go to bed and wake up each day (regularity).
Knocking these four levers into place—continuity, depth, duration, and regularity—will improve your cognitive and physical performance, decrease your risk of developing many diseases, boost your mood, bolster your immune system, and much more.
Sleep, along with exercise and nutrition, is the most powerful tool we have to live a longer and healthier life. Time to supercharge it.
The Rules
Rule 1: Finish eating 3 hours before bed.
Two reasons. Eating near bedtime can make you susceptible to acid reflux and other digestive problems once you lie down. Food can also have a thermic effect which means it may raise your core body temperature. This is an issue since to initiate and then stay asleep, your core body temperature needs to drop by 2-3℉.
If you must eat within three hours of your bedtime, stay away from simple carbs (fruits, milk products, cereal, processed foods) as they tend to be more rapidly translated into energy and ultimately heat.
Evolutionary Lens: Sleep Quality and Appetite
When someone is sleep deprived, their brain receives a signal that resembles starvation. This releases certain hormones that alter your appetite profile, drive you to want to eat more, and feel less satisfied after you eat.
Humans are the only species that will intentionally sleep deprive themselves. In the wild, sleep deprivation only happens if an animal is under the conditions of starvation. This evolutionary mechanism helps them stay awake in order to hunt or forage for food to sustain themselves.
But in our modern society of abundance this fake starvation signal, driven by inadequate sleep, harms us by signaling to our body that we’re undergoing starvation. This spikes a hormone called ghrelin (which makes you want to eat more) and suppresses a hormone called leptin (which makes you feel full).
Rule 2: Do not exercise within 2 hours of bed.
Exercise increases your core body temperature during and after which works against the 2-3℉ drop we need to initiate sleep. It also causes a profile of hormones (epinephrine, norepinephrine, adrenaline, and cortisol) to change which if released within two hours of bedtime hamper our ability to sleep.
Exercising outside of that two-hour pre-bed window is a fantastic tool for improving sleep, among the multitude of other benefits of exercise. Inversely, good sleep will improve your exercise.
High-quality sleep improves your motivation to do anything, making you prone to want to exercise. While exercising, your peak strength in compound lifts increases, your respiration improves, your likelihood of injury decreases, and the time it takes you to reach physical exhaustion goes up.
Rule 3: Set the thermostat to 18-20℃ (65-68℉).
If this feels too cold, it’s probably your extremities that need warming up. Heat your feet and hands by wearing socks, on your hands too if needed, or putting a hot water bottle by your feet.
Heating your feet and hands increases their blood flow and temperature while drawing both away from your core. This decrease in core body temperature is essential to initiating sleep. The cool thermostat temperature will keep you fast asleep for the rest of the night.
Schedule your thermostat to automatically rise to the normal temperature of your home in the last 15 minutes of sleep. This will make waking up much easier and reduce grogginess.
Rule 4: Take a hot shower (or sauna) before bed.
A hot shower or sauna ushers blood to the surface of your skin which causes heat to be dumped from the core of your body. The subsequent plummet in your core body temperature, once you get out, helps induce sleep.
Rule 5: Design a nighttime routine that involves one of these practices: relaxing body movements, meditation, and journaling.
Body Relaxation Movements
Stick to light stretching and movements, nothing should be strenuous or cause you to exert effort.
Meditation
Meditation is a fantastic tool for inducing sleep, especially for those who have difficulty shutting off their mind in bed. Here are a few ideas for picking a meditation that suits you. Ideally, use a self-guided meditation so you can store your phone in a separate room.
Journaling
An hour before bed, write down on paper all of the concerns or worries that are burdening you. Finish by writing three things you’re grateful for. The first part of this practice is extremely helpful to reduce racing thoughts and anxiety. Cementing your concerns on paper defines them and ceases the endless rumination that would otherwise occur.
Ending on a strong note with gratitude changes your frame of mind from a negative mood (worry) to a positive mood (gratefulness). Going to bed in a positive mood has been shown to reduce the amount of time it takes to fall asleep and increase sleep quality.
It’s also wise to stay away from anxiety and stress-inducing activities (social media, email) within an hour of your bedtime. These things cause you to contemplate negative thoughts and release the stress hormone cortisol which promotes wakefulness.
Rule 6: Switch off most of the lights in your house and avoid blue light 90 minutes before bed.
“[Light] is probably one of the most underappreciated factors that is contributing to poor sleep.” – Matthew Walker, Ph.D.
Limit light exposure and stay away from blue light (phones, tablets, LED bulbs…) 60-90 minutes before bed. In the natural world, dusk would signal to our brain to release melatonin in preparation for a healthy sleep cycle.
The modern world has given us easy access to never-ending light exposure. Light tricks your brain into thinking it’s daytime which counteracts your body’s natural rhythm and pre-sleep processes.
Rule 7: Remove all clocks from your bedroom. This includes electronic devices – charge them in a different room.
Having trouble falling asleep while watching the clock tick into the night may elicit an anxious response (“It’s 1 AM and I’m still awake!”) which will only excrete cortisol and further hinder you from falling asleep. Unplug the clocks.
Charging your phone in another room is the most effective way to prevent doom scrolling in bed. Even if it doesn’t feel like using your phone in bed is harming your ability to fall asleep, it’s lowering the quality of your sleep.
Rule 8: Go to bed and wake up at the same time each day.
Your body is designed for a regular cycle of sleep and wakefulness. Figure out your sleep chronotype, which will sit somewhere on the scale of early bird to night owl, by taking this sleep chronotype test.
Once you determine your optimal sleep schedule, stick with it the best you can including weekends. Your sleep chronotype is genetic and deviating from it will sacrifice sleep quality.
Rule 9: Calculate your sleep efficiency to align your sleep opportunity with desired sleep duration (7-9 hours per night).
Sleep Duration
This is the total amount of time you sleep each night. Aim for 7-9 hours per night. Remember, this is time asleep, NOT time spent in bed.
Sleep Efficiency
This measure compares how long you sleep to the time you spend in bed.
Sleep Efficiency = Time asleep ÷ Time spent in bed
If you sleep 7 hours out of 8 hours spend in bed, your sleep efficiency is about 88%. You can use this figure to calculate the sleep opportunity required to hit your desired sleep duration.
Sleep Opportunity
This is how long you should be in bed with an opportunity to sleep. If you want to hit a total sleep duration of 8 hours and have an efficiency of 88%, you must spend about 9 hours in bed (8 hours ÷ 88%).
Aim for a bare minimum of 8 hours of sleep opportunity per night.
Rule 10: Don’t lie in bed awake for long. Get out of bed, sit in dim light, and read a book. Return to bed when you’re sleepy.
Our brains are extremely associative. If you spend long periods of time awake in bed, your brain will start to think it’s a place to be awake, not asleep. To prevent or break that association, get out of bed, sit in dim light, and read a book or meditate until you feel sleepy enough to return to bed.
Rule 11: View sunlight outdoors within 30-60 minutes of rising and again in the evening prior to sunset.
If you’re awake before the sun is up, turn on artificial lights inside and go outside once the sun rises. Viewing (sun)light signals to your brain that it’s time to be awake.
If it’s bright and cloudless, 10 minutes of morning and afternoon sun is enough. On cloudy days aim for 20 minutes or 30 minutes if it’s very overcast. Don’t wear sunglasses during this practice, but as a general rule of thumb, the light is too bright if you have an urge to close your eyes or look away. Eyeglasses and contact lenses are okay.
If you live somewhere with very little light, consider purchasing an artificial daylight simulator source.
Rule 12: Halt caffeine consumption 8-14 hours before your bedtime.
For most people, caffeine has a half-life of about 6 hours and a quarter-life of 12 hours. This means that after 6 hours, 50% of the caffeine is still in your brain and after 12 hours 25% is still there. In practice, this means a quarter of the caffeine from a cup of java at noon is still in your system at midnight.
Of course, everyone has a different sensitivity to caffeine. But this refers to the wakeful impact of caffeine, NOT how it impacts your quality of sleep. This means that even if you’re not noticeably impacted by consuming caffeine, it can still harm your sleep quality.