Sleep is a basic need of being a human—you spend about one-third of your life doing it. Quality sleep is as essential to survival as food and water. Without sleep you can’t form or maintain the pathways in your brain that let you learn and create new memories, and it’s harder to concentrate and respond quickly. Sleep is important to a number of brain functions, including how neurons communicate with each other. In fact, your brain and body stay remarkably active while you sleep. Research suggests that sleep plays a housekeeping role that removes toxins in your brain that build up while you are awake.
Everyone needs sleep, but its biological purpose remains a mystery. Sleep affects almost every type of tissue and system in the body – from the brain, heart, and lungs to metabolism, immune function, mood, and disease resistance. Research shows that a chronic lack of sleep, or getting poor quality sleep, increases the risk of disorders including high blood pressure, cardiovascular disease, diabetes, depression, and obesity (Ninds.nih.gov, 2017).
Everyone needs sleep, but its biological purpose remains a mystery. Sleep affects almost every type of tissue and system in the body – from the brain, heart, and lungs to metabolism, immune function, mood, and disease resistance. Research shows that a chronic lack of sleep, or getting poor quality sleep, increases the risk of disorders including high blood pressure, cardiovascular disease, diabetes, depression, and obesity (Ninds.nih.gov, 2017).
Sleep Stages
There are two basic types of sleep: rapid eye movement (REM) sleep and non-REM sleep (which has three different stages). Each is linked to specific brain waves and neuronal activity. You cycle through all stages of non-REM and REM sleep several times during a typical night, with increasingly longer, deeper REM periods occurring toward morning (Ninds.nih.gov, 2017).
Stage 1:
non-REM sleep is the changeover from wakefulness to sleep. During this short period (lasting several minutes) of relatively light sleep, your heartbeat, breathing, and eye movements slow, and your muscles relax with occasional twitches. Your brain waves begin to slow from their daytime wakefulness patterns.
Stage 2:
non-REM sleep is a period of light sleep before you enter deeper sleep. Your heartbeat and breathing slow, and muscles relax even further. Your body temperature drops and eye movements stop. Brain wave activity slows but is marked by brief bursts of electrical activity. You spend more of your repeated sleep cycles in stage 2 sleep than in other sleep stages.
Stage 3:
non-REM sleep is the period of deep sleep that you need to feel refreshed in the morning. It occurs in longer periods during the first half of the night. Your heartbeat and breathing slow to their lowest levels during sleep. Your muscles are relaxed and it may be difficult to awaken you. Brain waves become even slower.
REM sleep:
first occurs about 90 minutes after falling asleep. Your eyes move rapidly from side to side behind closed eyelids. Mixed frequency brain wave activity becomes closer to that seen in wakefulness. Your breathing becomes faster and irregular, and your heart rate and blood pressure increase to near waking levels. Most of your dreaming occurs during REM sleep, although some can also occur in non-REM sleep. Your arm and leg muscles become temporarily paralyzed, which prevents you from acting out your dreams. As you age, you sleep less of your time in REM sleep. Memory consolidation most likely requires both non-REM and REM sleep.
Stage 1:
non-REM sleep is the changeover from wakefulness to sleep. During this short period (lasting several minutes) of relatively light sleep, your heartbeat, breathing, and eye movements slow, and your muscles relax with occasional twitches. Your brain waves begin to slow from their daytime wakefulness patterns.
Stage 2:
non-REM sleep is a period of light sleep before you enter deeper sleep. Your heartbeat and breathing slow, and muscles relax even further. Your body temperature drops and eye movements stop. Brain wave activity slows but is marked by brief bursts of electrical activity. You spend more of your repeated sleep cycles in stage 2 sleep than in other sleep stages.
Stage 3:
non-REM sleep is the period of deep sleep that you need to feel refreshed in the morning. It occurs in longer periods during the first half of the night. Your heartbeat and breathing slow to their lowest levels during sleep. Your muscles are relaxed and it may be difficult to awaken you. Brain waves become even slower.
REM sleep:
first occurs about 90 minutes after falling asleep. Your eyes move rapidly from side to side behind closed eyelids. Mixed frequency brain wave activity becomes closer to that seen in wakefulness. Your breathing becomes faster and irregular, and your heart rate and blood pressure increase to near waking levels. Most of your dreaming occurs during REM sleep, although some can also occur in non-REM sleep. Your arm and leg muscles become temporarily paralyzed, which prevents you from acting out your dreams. As you age, you sleep less of your time in REM sleep. Memory consolidation most likely requires both non-REM and REM sleep.
Tips for Better Sleep
If your sleep could use some improvements, here's the chronological list of tips, starting with when you wake up and continuing until bedtime.
1. Open Your Shades
Exposure to bright light first thing in the morning stops production of the sleep-inducing hormone melatonin and signals to your body that it's time to wake up. Outdoor sunlight is best, so you might even want to take a quick walk outside.
2. Make Your Bed
This is a psychological trick aimed at making your bedroom less cluttered — and therefore easier to relax in — come bedtime. You can also quickly put away any junk cluttering your nightstand and dresser.
3. Exercise
Exercise leads to better sleep at night. Many people schedule their full workouts for morning, which makes it easier to also exercise while fasting (an added benefit). If you don't have time for a full workout, at least do some quick stretching or bodyweight exercises.
4. Take a Walk Outdoors After Lunch
Not only will this increase in physical activity help you sleep later, but taking your walk outdoors gives you more exposure to bright sunlight. Light intensity is measured in lux units, and on any given day, the outdoor lux units will be around 100,000 at noon. Indoors, the typical average is somewhere between 100 to 2,000 lux units — about two orders of magnitude less. The brightness of the light matters, because your pineal gland produces melatonin roughly in approximation to the contrast of bright sun exposure in the day and complete darkness at night.
If you are in relative darkness all day long, it can't appreciate the difference and will not optimize your melatonin production. This, in turn, can have some rather significant ramifications for your health and sleep.
5. Cut Off Your Caffeine
If you're a coffee drinker, take your last caffeinated sip in the early afternoon (this applies to caffeinated soda, too). The caffeine can linger in your body for hours, blocking a brain chemical called adenosine that would otherwise help you to fall asleep.
6. Consider a Nap
We are biologically programmed to nap during the daytime, typically in the middle of the afternoon. The key is to avoid napping for too long, as this may disrupt your circadian rhythms, which would hurt your sleep instead of help it. The ideal nap time for adults appears to be around 20 minutes (any longer and you'll enter the deeper stages of sleep and may feel groggy when you wake up).
1. Open Your Shades
Exposure to bright light first thing in the morning stops production of the sleep-inducing hormone melatonin and signals to your body that it's time to wake up. Outdoor sunlight is best, so you might even want to take a quick walk outside.
2. Make Your Bed
This is a psychological trick aimed at making your bedroom less cluttered — and therefore easier to relax in — come bedtime. You can also quickly put away any junk cluttering your nightstand and dresser.
3. Exercise
Exercise leads to better sleep at night. Many people schedule their full workouts for morning, which makes it easier to also exercise while fasting (an added benefit). If you don't have time for a full workout, at least do some quick stretching or bodyweight exercises.
4. Take a Walk Outdoors After Lunch
Not only will this increase in physical activity help you sleep later, but taking your walk outdoors gives you more exposure to bright sunlight. Light intensity is measured in lux units, and on any given day, the outdoor lux units will be around 100,000 at noon. Indoors, the typical average is somewhere between 100 to 2,000 lux units — about two orders of magnitude less. The brightness of the light matters, because your pineal gland produces melatonin roughly in approximation to the contrast of bright sun exposure in the day and complete darkness at night.
If you are in relative darkness all day long, it can't appreciate the difference and will not optimize your melatonin production. This, in turn, can have some rather significant ramifications for your health and sleep.
5. Cut Off Your Caffeine
If you're a coffee drinker, take your last caffeinated sip in the early afternoon (this applies to caffeinated soda, too). The caffeine can linger in your body for hours, blocking a brain chemical called adenosine that would otherwise help you to fall asleep.
6. Consider a Nap
We are biologically programmed to nap during the daytime, typically in the middle of the afternoon. The key is to avoid napping for too long, as this may disrupt your circadian rhythms, which would hurt your sleep instead of help it. The ideal nap time for adults appears to be around 20 minutes (any longer and you'll enter the deeper stages of sleep and may feel groggy when you wake up).
7. Exercise in the Early Evening (If You Haven't Already)
The importance of exercise for sleep cannot be overstated, so if you didn't fit in your workout in the morning, be sure to do so later. There is some debate over how close is too close to bedtime to exercise. For some people, exercising too close to bedtime may keep you awake, but for others even late-night exercise seems to help (not hinder) sleep. One poll found that 83 percent of people said they slept better when they exercised (even late at night) than when they did not, so even if it's late, you may still want to exercise (National Sleep Foundation, 2013).
8. Take 15 Minutes to Unwind
If you're stressed, it's harder to fall asleep and stay asleep. Taking 15 minutes (at least) each day to relax may help your sleep significantly. You may try listening to music, journaling, meditation, or stretching. Do whatever works best for you.
The importance of exercise for sleep cannot be overstated, so if you didn't fit in your workout in the morning, be sure to do so later. There is some debate over how close is too close to bedtime to exercise. For some people, exercising too close to bedtime may keep you awake, but for others even late-night exercise seems to help (not hinder) sleep. One poll found that 83 percent of people said they slept better when they exercised (even late at night) than when they did not, so even if it's late, you may still want to exercise (National Sleep Foundation, 2013).
8. Take 15 Minutes to Unwind
If you're stressed, it's harder to fall asleep and stay asleep. Taking 15 minutes (at least) each day to relax may help your sleep significantly. You may try listening to music, journaling, meditation, or stretching. Do whatever works best for you.
9. Eat a Light Dinner and Stop Eating Three Hours Before Bed
If you eat a heavy meal too close to bedtime, your body will have to devote energy to digesting your food when it should be recharging during sleep. It is recommended that you stop eating three hours before bed and don't have your first meal until 13 to 18 hours later.
10. At Sundown, Dim Your Lights or Use Night Shift
In the evening (around 8 p.m.), you'll want to dim your lights and turn off electronic devices. Normally, your brain starts secreting melatonin between 9 p.m. and 10 p.m., and these devices emit blue light that may stifle that process. After sundown, shift to a low-wattage bulb with yellow, orange or red light if you need illumination.
A salt lamp illuminated by a 5-watt bulb is an ideal solution that will not interfere with your melatonin production. If using a computer or smartphone, install blue light-blocking software like f.lux, which automatically alters the color temperature of your screen as the day goes on, pulling out the blue wavelengths as it gets late. Another easy solution is to simply use amber-colored glasses that eliminate virtually all blue light. This way you don't have to worry about installing programs on all your devices or buying special light bulbs for evening use. Once you have your glasses on, it doesn't matter what light sources you have on in your house.
11. Turn Down the Volume
In the evening hours, you'll also want to keep noise to a minimum. Noise louder than a normal conversation may stimulate your nervous system and keep you awake. You may want to use a fan or other form of white noise to drown out noise disturbances while you sleep. The exception is listening to soft, soothing music, such as classical, which may actually help you to sleep (Jespersen, Koenig, Jennum & Vuust, 2015).
12. Take a Warm Bath About 1.5 Hours Before Bed
Thermoregulation — your body's heat distribution system — is strongly linked to sleep cycles. When you sleep, your body's internal temperature drops to its lowest level, generally about four hours after you fall asleep. Scientists believe a cooler bedroom may therefore be most conducive to sleep, since it mimics your body's natural temperature drop. This is also why taking a warm bath 90 to 120 minutes before bedtime may help you sleep; it increases your core body temperature, and when it abruptly drops when you get out of the bath, it signals your body that you are ready for sleep.
13. Adjust Your Bedroom Temperature
While there's no set consensus as to what temperature will help you sleep the best, in most cases any temperature above 75 degrees Fahrenheit and below 54 degrees F will interfere with your sleep. Some experts suggest 65 degrees F is ideal for sleep.
14. Sip a Cup of Chamomile Tea
Chamomile has sedative effects that may help with sleep, which is why chamomile tea is often sipped before bed. One study found that people with insomnia who took a chamomile supplement had improvements in daytime functioning and potential benefits on sleep measures as well (Zick, Wright, Sen & Arnedt, 2011). Try sipping a cup prior to bedtime to see if it helps you sleep.
15. Get Ready for Bed
A nightly ritual of washing your face, brushing your teeth and getting into your pajamas signals to your mind and body that it's time for bed. Try to stick with the same hygiene ritual, at the same time, each night.
16. Sleep in Complete Darkness
Once you're ready to climb into bed, make sure your bedroom is pitch black. The slightest bit of light in your bedroom can disrupt your body's clock and your pineal gland's melatonin production. You may want to cover your windows with drapes or blackout shades to achieve this and, if this isn't possible, wear an eye mask.
If you eat a heavy meal too close to bedtime, your body will have to devote energy to digesting your food when it should be recharging during sleep. It is recommended that you stop eating three hours before bed and don't have your first meal until 13 to 18 hours later.
10. At Sundown, Dim Your Lights or Use Night Shift
In the evening (around 8 p.m.), you'll want to dim your lights and turn off electronic devices. Normally, your brain starts secreting melatonin between 9 p.m. and 10 p.m., and these devices emit blue light that may stifle that process. After sundown, shift to a low-wattage bulb with yellow, orange or red light if you need illumination.
A salt lamp illuminated by a 5-watt bulb is an ideal solution that will not interfere with your melatonin production. If using a computer or smartphone, install blue light-blocking software like f.lux, which automatically alters the color temperature of your screen as the day goes on, pulling out the blue wavelengths as it gets late. Another easy solution is to simply use amber-colored glasses that eliminate virtually all blue light. This way you don't have to worry about installing programs on all your devices or buying special light bulbs for evening use. Once you have your glasses on, it doesn't matter what light sources you have on in your house.
11. Turn Down the Volume
In the evening hours, you'll also want to keep noise to a minimum. Noise louder than a normal conversation may stimulate your nervous system and keep you awake. You may want to use a fan or other form of white noise to drown out noise disturbances while you sleep. The exception is listening to soft, soothing music, such as classical, which may actually help you to sleep (Jespersen, Koenig, Jennum & Vuust, 2015).
12. Take a Warm Bath About 1.5 Hours Before Bed
Thermoregulation — your body's heat distribution system — is strongly linked to sleep cycles. When you sleep, your body's internal temperature drops to its lowest level, generally about four hours after you fall asleep. Scientists believe a cooler bedroom may therefore be most conducive to sleep, since it mimics your body's natural temperature drop. This is also why taking a warm bath 90 to 120 minutes before bedtime may help you sleep; it increases your core body temperature, and when it abruptly drops when you get out of the bath, it signals your body that you are ready for sleep.
13. Adjust Your Bedroom Temperature
While there's no set consensus as to what temperature will help you sleep the best, in most cases any temperature above 75 degrees Fahrenheit and below 54 degrees F will interfere with your sleep. Some experts suggest 65 degrees F is ideal for sleep.
14. Sip a Cup of Chamomile Tea
Chamomile has sedative effects that may help with sleep, which is why chamomile tea is often sipped before bed. One study found that people with insomnia who took a chamomile supplement had improvements in daytime functioning and potential benefits on sleep measures as well (Zick, Wright, Sen & Arnedt, 2011). Try sipping a cup prior to bedtime to see if it helps you sleep.
15. Get Ready for Bed
A nightly ritual of washing your face, brushing your teeth and getting into your pajamas signals to your mind and body that it's time for bed. Try to stick with the same hygiene ritual, at the same time, each night.
16. Sleep in Complete Darkness
Once you're ready to climb into bed, make sure your bedroom is pitch black. The slightest bit of light in your bedroom can disrupt your body's clock and your pineal gland's melatonin production. You may want to cover your windows with drapes or blackout shades to achieve this and, if this isn't possible, wear an eye mask.
Alternative Sleep Cycles
Monophasic Sleep
Monophasic is the most common sleep schedule in the world. Monophasic sleep consists of sleeping once per day, usually for between 7 and 9 hours per night. Monophasic is not the best way to sleep contrary to popular belief, but instead it is a byproduct of the long work hours of the industrial revolution that has remained a cultural norm even as work hours have shortened. |
Biphasic Sleep
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Triphasic Sleep
Triphasic is an efficient and simple schedule. There is little adaptation involved in a change from monophasic sleep to this schedule, and 3 to 5 hours extra are gained each day. The reason for its ease of adaption is that, similar to biphasic sleep, it aligns with the Circadian rhythm, with a nap after dusk, a nap before dawn, and a nap in the afternoon. A triphasic sleeper typically sleeps between 4 and 5 hours a day. |
Everyman Sleep
The everyman schedule is the most successful reduced-sleep schedule to date, it is constantly increasing in popularity, and people have achieved it without compromising their current health. While monophasic, biphasic, and triphasic schedules are all circadian centric schedules, everyman schedules rely on both circadian and ultradian rhythms. This makes everyman schedules have a significantly more difficult adaptation period than all of the previous schedules, as the consistency of times between sleeps matters much more. That being said, everyman is still significantly easier than any of the nap-only schedules. Everyman schedules include everyman 2 which is a with core sleep between 4.5 and 6 hours and two 20 minute naps; everyman 3, with a core between 3 and 4 hours and three 20 minute naps; and everyman 4 with a core between 1.5 and 2.5 hours, with four 20 minute naps. |
Dual Core Sleep
Dual core (DC) sleep is a derivative of the other schedules but with a core sleep around dusk, a core around dawn, and a number of naps in the afternoon. DC schedules can have the benefits of both segmented sleep and siestas and so is theoretically very healthy. DC1 is two cores totaling about 5 hours sleep, and one nap in the middle of the day. DC2 is two cores totaling about 4 hours sleep, and two naps throughout the day. DC3 is two cores totaling about 3h sleep, and three naps throughout the day. |
Uberman Sleep
Uberman is the most failed of polyphasic schedules. This is largely due to a misunderstanding of the difficulties associated with its adaptation period. Uberman is the most well known nap only schedule, and is an extension of the everyman schedules, to the point of getting rid of the core sleep entirely. While uberman is extremely difficult, it can have great benefits by increasing the amount of time in a person’s day drastically. An uberman will have 6 or 8 x20 minute naps a day, with total sleep time ranging from 2-3 hours a day. |
Dymaxion Sleep
Dymaxion is another popularly attempted schedule, although its difficulty is even greater than uberman, to the point of being nearly impossible. It’s predicted only the genetically mutated DEC2 gene ‘very short sleepers’ can be successful following such a schedule, which would includes far less than 1% of the world population. The dymaxion schedule was coined by Buckminster Fuller, and involves sleeping 4 times a day for 30 minutes. Even though the dymaxion schedule does not increase available awake time any more than uberman, it is prized for the increased convenience to the person’s social and work life. |
References
Jespersen, K., Koenig, J., Jennum, P. and Vuust, P. (2015). Music for insomnia in adults. Cochrane Database of Systematic Reviews. https://doi.org/10.1002/14651858.CD010459.pub2
National Sleep Foundation. (2013). Sleep in America Poll: Exercise and Sleep. [online] Available at: https://sleepfoundation.org/sites/default/files/RPT336%20Summary%20of%20Findings%2002%2020%202013.pdf [Accessed 19 Oct. 2017].
Ninds.nih.gov. (2017). Brain Basics: Understanding Sleep | National Institute of Neurological Disorders and Stroke. [online] Available at: https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Understanding-Sleep#dreaming [Accessed 19 Oct. 2017].
Polyphasic Society. (2017). Alternative Sleep Schedule Overviews. [online] Available at: https://www.polyphasicsociety.com/polyphasic-sleep/overviews/ [Accessed 19 Oct. 2017].
Zick, S., Wright, B., Sen, A. and Arnedt, J. (2011). Preliminary examination of the efficacy and safety of a standardized chamomile extract for chronic primary insomnia: A randomized placebo-controlled pilot study. BMC Complementary and Alternative Medicine, 11(1). https://doi.org/10.1186/1472-6882-11-78
National Sleep Foundation. (2013). Sleep in America Poll: Exercise and Sleep. [online] Available at: https://sleepfoundation.org/sites/default/files/RPT336%20Summary%20of%20Findings%2002%2020%202013.pdf [Accessed 19 Oct. 2017].
Ninds.nih.gov. (2017). Brain Basics: Understanding Sleep | National Institute of Neurological Disorders and Stroke. [online] Available at: https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Understanding-Sleep#dreaming [Accessed 19 Oct. 2017].
Polyphasic Society. (2017). Alternative Sleep Schedule Overviews. [online] Available at: https://www.polyphasicsociety.com/polyphasic-sleep/overviews/ [Accessed 19 Oct. 2017].
Zick, S., Wright, B., Sen, A. and Arnedt, J. (2011). Preliminary examination of the efficacy and safety of a standardized chamomile extract for chronic primary insomnia: A randomized placebo-controlled pilot study. BMC Complementary and Alternative Medicine, 11(1). https://doi.org/10.1186/1472-6882-11-78