Dr. Matthew Walker: The Science & Practice of Perfecting Your Sleep

Sleep is an intense evolutionary adaptive benefit and system. It is the single most effective thing one can do to reset brain and body health. Sleep is not a passive state, and in fact, sleep has an active state where rapid eye movement (REM) sleep occurs. During REM sleep, some parts of the brain are up to 30% more active than when awake. Sleep consists of two main types: non-REM sleep and REM sleep. Non-REM sleep is the calmest sleep, while REM sleep is the most active. Sleep is still a mystery that continues to be studied by neuroscientists and psychologists, but it is clear that getting enough quality sleep is crucial for physical and mental well-being.

During REM sleep, the brain paralyzes the body so that the mind can dream safely, which is necessary for survival. Autonomic storms during REM sleep can lead to erections in men and vaginal lubrication in women. The two voluntary muscle groups that are spurred from the paralysis are extra ocular muscles and inner ear muscle. It is difficult to differentiate between awake and REM sleep with only brainwave recordings, but eye and muscle movements help in distinguishing them. There may be waking states that also resemble slow wave sleep, non REM sleep, but further research is needed to confirm.

Deep non-REM sleep is the most important stage of sleep as it helps in consolidating memories, repairing tissues, and supporting immune function. The body goes through different stages of sleep throughout the night, including non-REM and REM sleep. Non-REM is further divided into four stages, with stages three and four being the deepest stages of sleep. During this stage, the body's cells fire and go silent in perfect coordination, which is a unique physical phenomenon. The body cycles through 90-minute cycles of non-REM and REM sleep throughout the night, with the majority of deep non-REM sleep occurring in the first half of the night. Consistent sleep patterns are important, but the sweet spot for sleep varies from person to person.

Getting sufficient amount of sleep and proper sleep cycles is crucial for optimizing performance, whether it's for doctors, pilots, or anyone. Red-eye flights or staying up too long at the wrong times can lead to decreased performance, physician-induced errors, and even suicidality in some cases. As the night progresses, the 90-minute sleep cycles mostly consist of REM sleep. However, skipping slow-wave sleep can lead to deficiency in deep sleep, regardless of the time sleep starts. Sleep states are interconnected, but mostly, the system needs to start at the beginning of the sleep cycle. Selective deprivation of different stages of sleep can be used for experimental purposes.

Sleep is critical for maintaining physical and mental health. Deprivation of either slow-wave or REM sleep can lead to different types of dysfunctions. Slow-wave sleep is important for musculature restoration and hormone regulation, while REM sleep is important for emotional balance and hormone production. Both forms of sleep are non-negotiable for human survival and have evolved over 3.6 million years. Interrupted sleep can have negative consequences, but it's essential to return to sleep as quickly as possible to minimize damage. It's important to prioritize sleep hygiene to help ensure a restful night's sleep.

It is natural to wake up during the night, especially as we age. Sleep efficiency is important, but quality is just as crucial for optimal functioning during waking hours. Waking up for short periods of time during the night is normal, and we should not worry about it too much. However, if it happens too frequently or for long periods of time, it may be worth looking into. Quality and quantity of sleep are equally important for our well-being, and we cannot have one without the other. Prioritizing good sleep hygiene can help us optimize our waking hours and improve overall health.

Sleep plays an essential role in our health, and getting proper sleep is crucial. The Uber men's schedule of sleeping in short bouts spread throughout the day is not beneficial and can have detrimental effects on performance and physiological measures. It is crucial to sleep in accordance with our natural biological edict, and getting exposure to natural daylight early in the day can affect our circadian rhythms, resulting in better quality and longer duration of life. Even on a cloudy day, natural sunlight is more potent than indoor lighting. Getting adequate sleep and exposure to natural light can benefit us not only physically but also mentally and emotionally.

Getting exposure to natural daylight early in the day can help align our circadian rhythms, improve sleep efficiency, and promote wakefulness. Stacking cues like exercise and light exposure can be an efficient way to do this. Using free apps like light meter can help measure the amount of light energy coming towards us and reveal the intensity of indoor and outdoor light. Delaying caffeine intake by 90 minutes to two hours after waking up can also help align our circadian rhythms and improve sleep quality. Caffeine interacts with adenosine receptors and delaying consumption allows natural wakefulness signals to take hold.

Caffeine works as a psychoactive stimulant, primarily by blocking the effects of adenosine, a chemical that builds up in our brain as we stay awake. This adenosine creates a sleep pressure, making us feel sleepier. By blocking adenosine, caffeine increases dopamine, which has an alerting effect. However, the timing and dose of caffeine matter, as too much can have negative effects, and ingesting it too late in the day can disrupt sleep. The process of sleepiness is not a mechanical pressure, but a chemical one. Caffeine disrupts this process by blocking the chemicals that promote sleepiness, thereby making us feel more alert. It's important to balance caffeine intake with sleep needs to avoid negative consequences.

Caffeine tricks our brain into feeling less tired by blocking adenosine receptors, which would normally make us feel sleepy. However, this doesn't deactivate the receptors, so when caffeine wears off, all the adenosine that has built up during that time floods the brain, causing the caffeine crash. This crash can disrupt the depth and architecture of our sleep, meaning even if we get 8-10 hours of sleep, it may not be as restorative as we think. The half-life of caffeine differs for each person and is determined by their liver's enzymatic speed in breaking it down. Some people may be more sensitive to caffeine than others due to gene variants that influence enzymatic speed.

Cutting off caffeine intake around 8-10 hours before bedtime is recommended to avoid shallow deep sleep and dependency cycle. This can drop the deep sleep by 30%, leaving you feeling unrestored and reaching for more coffee the next morning. Additionally, alcohol can bring you down but has deleterious impacts on sleep as well. Sleep is vital for all aspects of health and for performance. The messaging provided on the importance of sleep has positively impacted various communities. While having guidelines for caffeine intake is helpful, it's essential not to scare people who already struggle with sleep. It's crucial to communicate the science while being mindful of people's difficulties and not make matters worse.

Alcohol is not a sleep aid but a sedative that fragments sleep and blocks REM sleep. It may knock you out quicker but won't necessarily help you fall asleep naturally faster. It's important to prioritize the quality of sleep along with the quantity of sleep. Fragmented sleep induced by alcohol is usually not good quality sleep, even if you feel great the next day. It's critical to maintain a moderate amount of alcohol intake to avoid disrupting sleep patterns. While middle-ground adjustments are hard to achieve, drinking age-appropriate and avoiding alcohol before bedtime can help ensure healthy sleep patterns.

Getting enough sleep, especially REM sleep, is crucial for emotional and mental health, hormonal balance, and longevity. Even a single glass of wine with dinner can disrupt REM sleep and decrease growth hormone release, which is essential for metabolism and tissue repair. Insufficient REM sleep is associated with emotional instability and a range of psychiatric disorders. In fact, the amount of REM sleep one gets is the strongest predictor of their lifespan. Therefore, it is important to prioritize getting enough quality sleep, not just for productivity or energy levels, but for overall health and wellbeing.

Getting enough REM sleep is important for longevity and predicting lifespan. Exercise and movement are also crucial for overall mental and physical health. The return on investment for getting enough sleep and exercise is astronomical and can raise the health of all aspects of life. While alcohol's effect on sleep is not yet fully understood, timing and dose are essential factors in mitigating its negative effects. The podcast format allows for regular updates and corrections as new data emerges. Good sleep and exercise habits are crucial for public health, and individuals should prioritize both to improve their overall well-being.

Marijuana disrupts the depth of sleep and architecture of sleep, and both THC and CBD are considered sedatives. THC seems to speed up the time of falling asleep but through different mechanisms block REM sleep. REM sleep is crucial for brain function and memory consolidation. Alcohol has the same mechanism as THC, blocking REM sleep. Brain's clever homeostatic mechanism tries to get back all the REM sleep that it's lost in the middle of the night and builds up pressure for REM sleep. You might not get back all the REM sleep, but the brain will start to devour more because it's been starved of REM sleep for so long. It is important to maintain a balance and make informed choices for a relaxed and enjoyable life.

Regular use of THC for sleep can lead to dependency and tolerance, causing a need for more to achieve the same sleep benefit. Discontinuing THC use results in severe rebound insomnia and anxiety withdrawal. CBD, on the other hand, does not have the same detrimental effects as THC. Low dose CBD can promote wakefulness, while higher doses can cause sedation. Its potential benefits for sleep are attributed to its thermo-regulatory and anxiety-reducing effects. However, there is still a lack of data to make conclusive statements about the effectiveness of CBD for sleep. It is important to also consider the purity and accuracy of CBD supplements before attributing any effects to CBD itself.

CBD can modulate the sensitivity of the brain to adenosine, creating a stronger pressure for sleep. THC, CBD, caffeine, and alcohol should be used in moderation at the appropriate times to ensure healthy sleep. Melatonin is a hormone of darkness that is inhibited by light, and is naturally produced by the pineal gland in response to decreasing light levels. Melatonin receptors in the brain are responsible for regulating our central 24-hour clock. The brain clock is regulated by external factors such as daylight and food to prevent us from drifting forward in time and disrupting our sleep.

Melatonin communicates to the brain and body when it's time to sleep and when it's time to awake by releasing chemical signals of 24 hour nurse of light and day. Melatonin helps with the timing of the onset of sleep but not with the generation of sleep itself. Evidence shows that in healthy adults who are not of older age, melatonin is not particularly helpful as a sleep aid. However, for people undergoing insufficient sleep, melatonin could have a sleep benefit because it drops core body temperature. Temperature is not just a reflection of brain state and wakefulness, but also a lever that is quite powerful.

Melatonin supplementation can help induce a sleepy state but it's not a guarantee for sound sleep. A drop in core body temperature by about 1 degree Celsius is needed for us to fall asleep and stay asleep. Melatonin supplements available in the market range anywhere from 1-20 milligrams but a normal night's release of melatonin would be far lower. The optimal dose for sleep benefits is between 0.1 and 0.3 milligrams, which is 10-20 times lower than what is normally available. Higher than normal doses of melatonin can have detrimental effects and it's concerning as it affects the reproductive axis. Melatonin supplementation is prescribed to older adults with insomnia, as they tend to have a flatter curve of melatonin release throughout the night.

Supplements, especially melatonin and magnesium, need to be taken with caution as the dosage and quality of the supplement can vary greatly. While magnesium deficiency can lead to sleep problems, supplementing with it does not guarantee better sleep, especially for healthy individuals. Melatonin can range from 83% less to 478% more than what is labelled, making it important to consider the timing and dosage. It is also important to choose a reputable brand. Additionally, those who are concerned about hormone intake should avoid medications that are known to be androgen suppressive at high levels. Overall, one's health and specific needs should be considered before taking any supplement.

Valerian root may not actually improve sleep based on studies, but individuals may still experience a placebo effect. However, tart cherry juice has been shown in independent studies to potentially increase sleep by up to 84 minutes and decrease the amount of time spent awake at night by over an hour. More refined studies could isolate the real effects and determine if the benefits translate when ingesting tart cherries in different forms, such as capsules. As scientists, being open-minded is crucial to exploring the potential benefits of supplements, and individuals should be responsible for their own health when taking these supplements.

Tart cherry may be an intriguing potential sleep aid and may increase sleep by around 84 minutes. Supplements like apigenin, a derivative of chamomile, may also help improve sleep. However, it's important to note that not all natural supplements are safe, and not all pharmaceuticals are effective. The best approach is to keep an open mind, experiment with positive and negative measures, and balance subjective and objective sleep metrics to assess the effects of any supplement. The absence of evidence is not evidence of absence, so it's worth trying out potential sleep aids if they seem promising, but also important to carefully monitor their effects.

When it comes to optimizing sleep, there are many low-hanging fruit options that don't require supplements or drugs. Cognitive behavioral therapy for insomnia can be as effective as sleeping pills and have long-term benefits. Kiwifruits have been found to decrease the speed of time it takes to fall asleep, stay asleep for longer, and spend less time awake throughout the night. The skin of the kiwifruit may contain some of the good stuff that induces sleep. Mechanistically, Kiwi fruit's sleep benefits may be mediated by the brain's natural inhibitory neurotransmitter system called GABA system. Before supplementing, it's essential to consider one's behavior, light viewing habits, etc. and use supplements as the last resort.

Serotonin plays a crucial role in the sleep-wake cycle and needs to be modulated in specific ways during different stages of sleep. Artificially increasing serotonin levels at night can lead to the fragmentation of REM sleep. Similarly, supplementing with tryptophan or serotonin may not be a good idea for everyone. The data on their impact on sleep is all over the map, with some reporting improved sleep and others experiencing lingering after-effects. Instead of focusing on supplements and chemicals, it may be more beneficial to adopt pro-sleep behaviors like taking naps, doing relaxation exercises, yoga, or hypnosis to improve sleep quality.

Napping can have great benefits like improved cardiovascular health, learning, memory, and emotional regulation. Naps should be limited to 20-90 minutes, with a 90 minute window being ideal to obtain both non-REM and REM sleep. Sleep inertia, a window of grogginess, should be expected after napping, and experts suggest waiting for some time before engaging in any tasks. However, napping can also be dangerous; it can make sleep problems like insomnia worse. People who struggle with sleep at night are advised to stay away from naps, and if they must nap, they should limit it to 20-25 minutes and avoid napping late in the afternoon.

Sleep is a human right, and no one should feel guilty about napping or getting the sleep they need. However, it is important to avoid oversleeping as it can lead to hypersomnia and shorter life expectancy. Finding the sweet spot of 7-9 hours of sleep is crucial for longevity. While some people may need naps to enhance productivity, others may feel worse if they wake up from deep sleep. It's essential to understand individual differences while discussing sleep patterns. Therefore, society needs to remove the stigma surrounding sleep and consider it as an essential aspect of human health. Outliving our competition is also a good reason to prioritize quality sleep.

Sleep is not the enemy, but poor quality sleep can be, leading people to oversleep in an effort to compensate. Sleep is the Swiss army knife of health and often the body's way of responding to mortality risk. While it's possible to oversleep like overeating or over-hydrating, most people are not in danger of getting too much sleep. The key is to aim for 7-9 hours of high-quality sleep, and individuals should focus on sleep quality as well as quantity. Sex and orgasm before sleep can be beneficial due to a post-orgasmic increase in prolactin, a naturally occurring sedative, and oxytocin, which can dissipate the fight or flight branch of the nervous system leading to better sleep.

Getting quality sleep is crucial for overall health, and sexual activity can play a role in improving sleep. Both subjective and objective data suggests that sex resulting in orgasm can improve sleep quality. Masturbation can also be a useful tool for sleep improvement. However, it's important to have age, context, and species-appropriate discussions around sexual behavior. Hormones like estrogen and testosterone play a crucial role in sexual development and experience, and sleep disruption can lead to hormonal imbalance and menstrual cycle disruption. Women who get an extra hour of sleep have a 14% increase in interest in becoming sexually intimate with their partner. Overall, sleep and sexual behavior can influence each other, and both are important for a healthy and happy life.

Restful sleep is crucial for a healthy relationship, as poor sleep can lead to more frequent and brutal fights and lower chances of resolving conflicts due to decreased empathy. Sexual behavior between two consenting individuals, when done in a healthy and appropriate context, can increase sex steroid hormones to healthy ranges. Sleep and sex are controlled by the same areas in the hypothalamus, underscoring the importance of both for overall biological health. While there are many known sleep tips such as keeping the room cool and avoiding alcohol, CBD, and marijuana, there may be unconventional or lesser-known methods worth exploring to improve sleep quality.

After a bad night of sleep, avoid waking up later, sleeping in, napping, or consuming extra caffeine to make up for it. Stick to your natural bedtime and don't rush into bed. Gradually wind down with a consistent bedtime routine that works for you. Avoid counting sheep to fall asleep and take yourself on a relaxing mental walk instead. These unconventional tips, along with sleep hygiene habits like regularity, temperature, and darkness, can help improve the quality of your sleep and prevent insomnia. Lack of sleep can negatively impact our health, so it's important to prioritize and optimize our sleep routine.

Writing down worries and concerns in a journal before bed can decrease the time it takes to fall asleep by 50%. Difficulty and anxiety at night in the dark is not the same as in the light of day because those thoughts come with a magnitude of rumination and catastrophization disproportionate to those when awake. Removing all clock faces from the bedroom can be helpful on tough nights because knowing the time does not help in any way and only makes matters worse. These tips are unconventional, but they have been found helpful according to studies by sleep experts.

Sleep is an important aspect of our lives and understanding its positive and negative regulators can lead to a better path. It is commendable that scientists like Matt Walker share their knowledge in public and offer tremendous advice and considerations. Being a sleep ambassador is a privilege and we need more people like him to champion the importance of sleep. We can benefit in myriad ways if we take the advice and apply it in our lives. It is important to acknowledge the efforts of scientists and clinicians who work hard to provide the best for people and communicate their knowledge effectively. We can learn more about the work of Matt Walker and his colleagues through his Twitter account.