lordgandy2000
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Writing this as I wanted to stress the importance of some factors which are not widely known but are fundamental to sleep. Sleep research is a very new field in general and of great academic and personal interest to me. Previous sleep guides covered some good tips but I felt were lacking in emphasizing the importance of certain factors.
TLDR: sleep is a largely physiological process highly dependent on core body temperature resulting from light/ dark exposure to the eyes. If you're worrying about Vitamin D3, melatonin, or relaxation techniques without taking care of your light/ dark exposure, you're missing the forest for the trees.
Importance of Sleep (already been emphasized many times by users here)
See: https://looksmax.org/threads/the-importance-of-sleep.133336/
Also: https://looksmax.org/threads/how-to-sleep-correctly-and-why.17477/
4 Main Processes Driving Sleep
- Circadian Rhythm/ Body Clock
- Homeostatic Sleep Pressure
- Ultradian Rhythm
- Psychological Factors
Circadian Rhythm/ Body Clock
- Roughly 24h cycle that regulates all body processes
- Greatest tendency to sleep occurs during a) your circadian night, and b) your circadian siesta (when people nap in the afternoon)
- Sleep is induced when the hypothalamus reduces core body temperature in response to light and darkness
- Most powerful signal to manipulate the circadian rhythm is Light and Darkness as detected by the eyes
- Other signals that can shift the body clock are temperature, food, exercise, melatonin, body posture, and socializing
- This process explains why you sleep/ have bowel movements at mostly the same time everyday
- Also explains jetlag which is a sudden drastic shift in light/ dark exposure
Image: daily variation in core body temperature. Note the drops in temperature during the circadian night beginning at ~11pm, as well as the afternoon dip in temperature during the circadian siesta at ~11am
Homeostatic Sleep Pressure
- Tendency for sleep increases linearly with time awake, akin to pressure accumulating
- Sleep pressure dissipates when you sleep
- Coffee keeps you awake by reducing buildup of sleep pressure
- This process is why you feel tired if you stay up the entire night (excessive sleep pressure has built up), and why you generally don't feel tired when you wake up from a long sleep (you've dissipated most of your sleep pressure)
Ultradian Cycle
- 80 min to 2h mini cycles within your circadian rhythm
- Increased tendency for sleep occurs in the 20-30 mins between each ultradian cycle
- Explains why afternoon naps without alarms are usually in multiples of 80mins-2h (without alarms I either nap 80 min or 2h 40min, no in between)
- Also explains why if you feel sleepy at night and resist the urge to sleep for 20-30 mins, you won't feel tired until the next ultradian cycle
Psychological Factors
- Psychological state is dependent on your circadian rhythm. You feel more active during your circadian day and more relaxed during your circadian night
- Can be influenced acute stimuli or autonomous decisions (i.e. viewing rage-inducing evisceration threads at night)
- You need to take advantage of all 4 of these processes to sleep well
HOW TO SLEEP BETTER (in descending order of importance)
1. Consistency in timing of retinal light exposure, and sleep/ wake times
- Most recommendations for consistency ignore consistency in light/ dark exposure
- Sleep/ wake times is not consciously determined by your choice , but follow your light/ dark exposure as in jetlag
- Expose your eyes to light at the same time in the morning and dim the lights at the same time at night everyday
- Evolutionary purpose of the circadian rhythm is behavioral consistency with 24h periodicity
- Aberrant timing of light exposure is the cause of jetlag & reduced sleep quality
2. Very bright days and very dark evenings and nights
- Modern humans are exposed to very little daytime bright light and more nighttime bright light, the opposite of the natural tendency
- Camping with no artificial lights and only outdoor sunlight completely reset and entrained the circadian rhythm
- Bright days and dark nights increase circadian amplitude (strength), boosting daytime wakefulness and nighttime sleepiness
- It is generally much brighter outdoors than indoors, even on gloomy days (unless you live at extreme latitudes)
- Light Intensity: should be sufficiently bright without causing discomfort, although there is a saturation point beyond which there is no difference in impact
- Light Duration: the longer the duration, the greater the circadian impact. A slightly less bright long exposure can be better than a very bright short exposure
- Light Angle: Daytime light should optimally reach your eyes from all directions, particularly your peripheral vision, as opposed to a single focused light source, as ipRGCs respond best to light in your peripheral vision (located mainly in the parafovea of the macula and nasal retinal region)
- Light Color: Blue light has the greatest circadian impact, 400 lux of blue light is equivalent 10,000 lux of white light. Sunlight is rich in blue light
- Darken your room totally during sleep. Even dim lights in your eyes at night disrupt the circadian rhythm. See also here
- The brighter the daytime light exposure, the lesser the disruptive impacts of nighttime light on sleep. Also here.
3. Sleep during Circadian Night
- Sleep duration and quality (particularly REM sleep)is reduced when sleeping outside the circadian night as you are only relying on homeostatic sleep pressure
- Best way to determine your circadian night is to track your core body temperature, which dips during the circadian night
- Alternatively, the circadian night begins ~12h after the circadian siesta. If you start feeling an urge to nap at 1pm in the afternoon, the circadian night begins at ~1am
4. Dim the lights & avoid blue light starting 2-3h before your sleep time
- Blue light has the most impact on your circadian rhythm, so avoidance of evening blue/ bright lights prevents circadian disruption
- Dim electronic devices to min brightness & use flux app to make the screen colors warmer
- Photic history: brighter daytime light exposure reduces disruptive impacts of nighttime light and vice versa
5. Avoid excessively long afternoon naps close to bedtime
- Dissipates sleep pressure
- How long & how close depends on individual, some accumulate sleep pressure faster than others
- Rule of thumb: determine your circadian night as in point (3), your afternoon nap should not be too long and should end at least 9h before bedtime
6. Avoid procrastination when you feel sleepy at night
- The 20-30 mins between ultradian cycles carries increased tendency for sleep
- So if you feel tired at night, go to sleep and don't procrastinate; the sleepiness may disappear until the next ultradian cycle
7. Avoid the dopaminergic wake maintenance zone
- Every evening before body temperature drops and melatonin secretion begins, a dopamine surge prevents sleep
- Occurs 1-3h before usual bedtime, so avoid sleeping 1-3h earlier from one day to the next unless you have shifted your circadian rhythm with light/ dark therapy
8. Keep your room comfortably cool
- Ideally 60-70F (16-22 Celsius)
- Aids in core body temperature reduction needed to induce and maintain sleep
9. Warm shower 2-3h before bed
- Common misconception: cold showers actually raise your body temperature as they cause vasoconstriction, preventing heat loss
- Warm showers cause vasodilation and help heat loss, helping reduce core body temperature if done 2-3h before bed
10. Avoid eating near bedtime or during your circadian night
- Digesting food raises body temperature , which disrupts the natural dip in core body temperature needed to induce sleep
- The digestive system also releases 400x more melatonin than the pineal gland and is dependent on food intake timing
- However, your brain needs energy to last throughout the night, so don't starve yourself before bed either
11. Exercise during the day & not too near your bedtime
- You are strongest when your core body temperature is highest during the circadian day
- Studies show exercise aids sleep as long as its done more than ~90min before bedtime to give your body time to cool down
12. Avoid coffee, marjuana, and alcohol
- Coffee's impact is very individual, some are very affected while others aren't
- Optimally, don't take caffeine at all. If you have to, drink it in the morning well before bedtime
- Caffeine has a half life of ~5h in humans, so if you drink it at 8am, there's still 12.5% of that amount remaining at 11pm which may disrupt sleep
- Marjuana and alcohol disrupt sleep quality, hormone release, and cause circadian misalignment. Also massive looksmins in general
13. Take instant-release melatonin before the DLMO
- DLMO (dim light melatonin onset) occurs when the lights are dimmed ~2h before your normal bedtime
- Melatonin can consolidate sleep and prevent sleep fragmentation
- Taking exogenous melatonin is less important, your body (particularly your digestive system) produces a lot of melatonin in absence of light
- Light has a much greater impact on sleep than exogenous melatonin and can eliminate melatonin
- While studies have shown melatonin can cause drowsiness upon waking, you can eliminate this by exposure to bright light
14. Relaxation/ Psychological Aids
- Don't read rage-inducing threads before bed
- Ultimately, sleep is a highly physiological process dependent on light inputs and core body temperature
- If your circadian rhythm is properly entrained and your sleep pressure is correct, you will feel tired at the correct time no matter your cognitive state
Note: if you're wondering why I didn't really touch on sleep hygiene, its because its efficacy is questionable. IMO it helps but if and only if you get the importance stuff right first (light/ dark therapy, circadian and homeostatic factors etc.) Similarly, while CBT-i is effective in treating insomnia, it does not address the main cause of sleep issues in the 21st century. I also didn't cover sleep apnea or particular conditions like narcolepsy as they go beyond the scope of a general guide
TLDR: sleep is a largely physiological process highly dependent on core body temperature resulting from light/ dark exposure to the eyes. If you're worrying about Vitamin D3, melatonin, or relaxation techniques without taking care of your light/ dark exposure, you're missing the forest for the trees.
Importance of Sleep (already been emphasized many times by users here)
See: https://looksmax.org/threads/the-importance-of-sleep.133336/
Also: https://looksmax.org/threads/how-to-sleep-correctly-and-why.17477/
4 Main Processes Driving Sleep
- Circadian Rhythm/ Body Clock
- Homeostatic Sleep Pressure
- Ultradian Rhythm
- Psychological Factors
Circadian Rhythm/ Body Clock
- Roughly 24h cycle that regulates all body processes
- Greatest tendency to sleep occurs during a) your circadian night, and b) your circadian siesta (when people nap in the afternoon)
- Sleep is induced when the hypothalamus reduces core body temperature in response to light and darkness
- Most powerful signal to manipulate the circadian rhythm is Light and Darkness as detected by the eyes
- Other signals that can shift the body clock are temperature, food, exercise, melatonin, body posture, and socializing
- This process explains why you sleep/ have bowel movements at mostly the same time everyday
- Also explains jetlag which is a sudden drastic shift in light/ dark exposure
Image: daily variation in core body temperature. Note the drops in temperature during the circadian night beginning at ~11pm, as well as the afternoon dip in temperature during the circadian siesta at ~11am
Homeostatic Sleep Pressure
- Tendency for sleep increases linearly with time awake, akin to pressure accumulating
- Sleep pressure dissipates when you sleep
- Coffee keeps you awake by reducing buildup of sleep pressure
- This process is why you feel tired if you stay up the entire night (excessive sleep pressure has built up), and why you generally don't feel tired when you wake up from a long sleep (you've dissipated most of your sleep pressure)
Ultradian Cycle
- 80 min to 2h mini cycles within your circadian rhythm
- Increased tendency for sleep occurs in the 20-30 mins between each ultradian cycle
- Explains why afternoon naps without alarms are usually in multiples of 80mins-2h (without alarms I either nap 80 min or 2h 40min, no in between)
- Also explains why if you feel sleepy at night and resist the urge to sleep for 20-30 mins, you won't feel tired until the next ultradian cycle
Psychological Factors
- Psychological state is dependent on your circadian rhythm. You feel more active during your circadian day and more relaxed during your circadian night
- Can be influenced acute stimuli or autonomous decisions (i.e. viewing rage-inducing evisceration threads at night)
- You need to take advantage of all 4 of these processes to sleep well
HOW TO SLEEP BETTER (in descending order of importance)
- Consistency in timing of light exposure, and sleep/ wake times
- Bright days + dark nights
- Sleep during your circadian night
- Dim lights & avoid blue light starting 2-3h before bedtime
- Avoid excessively long afternoon naps close to bedtime
- Avoid procrastination when you feel sleepy at night
- Avoid the dopaminergic wake maintenance zone
- Keep your room comfortably cool
- Warm shower ~2h before bed
- Avoid eating near bedtime or during your circadian night
- Exercise during the day & not too near your bedtime
- Avoid coffee, marjuana, and alcohol
- Take instant-release melatonin before DLMO
- Relaxation/ Psychological Aids
1. Consistency in timing of retinal light exposure, and sleep/ wake times
- Most recommendations for consistency ignore consistency in light/ dark exposure
- Sleep/ wake times is not consciously determined by your choice , but follow your light/ dark exposure as in jetlag
- Expose your eyes to light at the same time in the morning and dim the lights at the same time at night everyday
- Evolutionary purpose of the circadian rhythm is behavioral consistency with 24h periodicity
- Aberrant timing of light exposure is the cause of jetlag & reduced sleep quality
2. Very bright days and very dark evenings and nights
- Modern humans are exposed to very little daytime bright light and more nighttime bright light, the opposite of the natural tendency
- Camping with no artificial lights and only outdoor sunlight completely reset and entrained the circadian rhythm
- Bright days and dark nights increase circadian amplitude (strength), boosting daytime wakefulness and nighttime sleepiness
- It is generally much brighter outdoors than indoors, even on gloomy days (unless you live at extreme latitudes)
- Light Intensity: should be sufficiently bright without causing discomfort, although there is a saturation point beyond which there is no difference in impact
- Light Duration: the longer the duration, the greater the circadian impact. A slightly less bright long exposure can be better than a very bright short exposure
- Light Angle: Daytime light should optimally reach your eyes from all directions, particularly your peripheral vision, as opposed to a single focused light source, as ipRGCs respond best to light in your peripheral vision (located mainly in the parafovea of the macula and nasal retinal region)
- Light Color: Blue light has the greatest circadian impact, 400 lux of blue light is equivalent 10,000 lux of white light. Sunlight is rich in blue light
- Darken your room totally during sleep. Even dim lights in your eyes at night disrupt the circadian rhythm. See also here
- The brighter the daytime light exposure, the lesser the disruptive impacts of nighttime light on sleep. Also here.
3. Sleep during Circadian Night
- Sleep duration and quality (particularly REM sleep)is reduced when sleeping outside the circadian night as you are only relying on homeostatic sleep pressure
- Best way to determine your circadian night is to track your core body temperature, which dips during the circadian night
- Alternatively, the circadian night begins ~12h after the circadian siesta. If you start feeling an urge to nap at 1pm in the afternoon, the circadian night begins at ~1am
4. Dim the lights & avoid blue light starting 2-3h before your sleep time
- Blue light has the most impact on your circadian rhythm, so avoidance of evening blue/ bright lights prevents circadian disruption
- Dim electronic devices to min brightness & use flux app to make the screen colors warmer
- Photic history: brighter daytime light exposure reduces disruptive impacts of nighttime light and vice versa
5. Avoid excessively long afternoon naps close to bedtime
- Dissipates sleep pressure
- How long & how close depends on individual, some accumulate sleep pressure faster than others
- Rule of thumb: determine your circadian night as in point (3), your afternoon nap should not be too long and should end at least 9h before bedtime
6. Avoid procrastination when you feel sleepy at night
- The 20-30 mins between ultradian cycles carries increased tendency for sleep
- So if you feel tired at night, go to sleep and don't procrastinate; the sleepiness may disappear until the next ultradian cycle
7. Avoid the dopaminergic wake maintenance zone
- Every evening before body temperature drops and melatonin secretion begins, a dopamine surge prevents sleep
- Occurs 1-3h before usual bedtime, so avoid sleeping 1-3h earlier from one day to the next unless you have shifted your circadian rhythm with light/ dark therapy
8. Keep your room comfortably cool
- Ideally 60-70F (16-22 Celsius)
- Aids in core body temperature reduction needed to induce and maintain sleep
9. Warm shower 2-3h before bed
- Common misconception: cold showers actually raise your body temperature as they cause vasoconstriction, preventing heat loss
- Warm showers cause vasodilation and help heat loss, helping reduce core body temperature if done 2-3h before bed
10. Avoid eating near bedtime or during your circadian night
- Digesting food raises body temperature , which disrupts the natural dip in core body temperature needed to induce sleep
- The digestive system also releases 400x more melatonin than the pineal gland and is dependent on food intake timing
- However, your brain needs energy to last throughout the night, so don't starve yourself before bed either
11. Exercise during the day & not too near your bedtime
- You are strongest when your core body temperature is highest during the circadian day
- Studies show exercise aids sleep as long as its done more than ~90min before bedtime to give your body time to cool down
12. Avoid coffee, marjuana, and alcohol
- Coffee's impact is very individual, some are very affected while others aren't
- Optimally, don't take caffeine at all. If you have to, drink it in the morning well before bedtime
- Caffeine has a half life of ~5h in humans, so if you drink it at 8am, there's still 12.5% of that amount remaining at 11pm which may disrupt sleep
- Marjuana and alcohol disrupt sleep quality, hormone release, and cause circadian misalignment. Also massive looksmins in general
13. Take instant-release melatonin before the DLMO
- DLMO (dim light melatonin onset) occurs when the lights are dimmed ~2h before your normal bedtime
- Melatonin can consolidate sleep and prevent sleep fragmentation
- Taking exogenous melatonin is less important, your body (particularly your digestive system) produces a lot of melatonin in absence of light
- Light has a much greater impact on sleep than exogenous melatonin and can eliminate melatonin
- While studies have shown melatonin can cause drowsiness upon waking, you can eliminate this by exposure to bright light
14. Relaxation/ Psychological Aids
- Don't read rage-inducing threads before bed
- Ultimately, sleep is a highly physiological process dependent on light inputs and core body temperature
- If your circadian rhythm is properly entrained and your sleep pressure is correct, you will feel tired at the correct time no matter your cognitive state
Note: if you're wondering why I didn't really touch on sleep hygiene, its because its efficacy is questionable. IMO it helps but if and only if you get the importance stuff right first (light/ dark therapy, circadian and homeostatic factors etc.) Similarly, while CBT-i is effective in treating insomnia, it does not address the main cause of sleep issues in the 21st century. I also didn't cover sleep apnea or particular conditions like narcolepsy as they go beyond the scope of a general guide
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