Published August 2021 on YouTube

Dr. Matthew Walker: The Science & Practice of Perfecting Your Sleep | Huberman Lab Podcast #31

1. Introducing Dr. Matt Walker

Dr. Matthew shares insights on how to improve sleep quality and performance through behavioral protocols, light, temperature, supplementation, food, exercise, and sex. He also discusses the importance of naps, compensation for lost sleep, and the consequences of poor sleep.

2. Science and Health

Andrew discusses the importance of science and health, and how Roca, Inside Tracker, and Bel Campo are contributing to these fields. He highlights the science behind Roca's glasses, Inside Tracker's personalized nutrition platform, and Bel Campo's regenerative agriculture.

3. What Is Sleep?

Dr. Matt Walker explains the complex physiological benefits of sleep and how it is the single most effective thing you can do to reset your brain and body health. The changes in brainwave activity during sleep are far more dramatic than those when we're awake, and the active state of sleep is not a passive state.

4. REM Sleep Paradox

REM Sleep Paradox:Matt and Andrew discuss the paradoxical nature of REM sleep, where the brain is highly active but the body is completely paralyzed. They explain how eye and muscle activity can be used to differentiate between REM sleep and wakefulness, and how the brainstem plays a crucial role in this process.
REM Sleep Paradox:Matt and Andrew discuss the paradox of REM sleep, where the brain paralyzes the body to dream safely, but the involuntary muscles keep functioning. They also talk about autonomic storms and how they cause erections and vaginal discharge during sleep, despite the body being paralyzed.

5. Slow Wave Sleep aka 'Deep Sleep'

Sleep Architecture:Matt and Andrew discuss the architecture of sleep, specifically the different stages of non-REM and REM sleep. Matt explains the four stages of non-REM sleep and how deep non-REM sleep is rarely achieved in waking states. They also touch on chronotypes and how different people have different sleep preferences.
Sleep Stages:Matt and Andrew discuss the different stages of non-REM sleep, including the physiological changes that occur such as heart rate and brainwave activity. They also highlight the remarkable coordination of cells in the cortex during this stage.
Sleep Cycles:Matt Walker explains the stages of sleep cycles and how they change throughout the night. Andrew Huberman emphasizes the importance of adequate sleep for optimal performance and safety, particularly for pilots and physicians.

6. Compensating For Lost Sleep

Sleep Cycle Reciprocity:Matt Walker explains that there is some degree of reciprocity between the different sleep states, but mostly if you are forced to skip the slow wave sleep part of the night, you will mostly go into your REM sleep phases and be significantly deficient in your deep sleep.
Sleep Stages:Matt and Andrew discuss the effects of selectively depriving people of either slow wave sleep or REM sleep. They explore the differences between the two stages and how they contribute to the restorative and emotional aspects of sleep. The outcome measure determines whether it is better to get the early or later part of the night's sleep.
Sleep and Evolution:Matt and Andrew discuss the importance of sleep and how it has survived evolution despite its seemingly detrimental effects on survival. They explore the different stages of sleep and their impact on hormones and bodily functions, highlighting the non-negotiable nature of sleep for optimal health.

7. Waking in the Middle Of The Night

Sleep Interruptions:Andrew and Matt discuss the impact of waking up in the middle of the night on sleep quality and overall health. They explain how it is normal to wake up briefly during the night and offer insights on how to improve sleep hygiene.
Normal Sleep Interruptions:Matt explains that waking up in the middle of the night is normal and we don't need to worry about it too much. He emphasizes that sleep efficiency is more important than the total amount of sleep we get. However, if we are awake for more than 25 minutes or wake up frequently throughout the night, we should look into it.

8. Sleep Like an Adult

Matt Walker shares insights on the Uberman Schedule, a sleep schedule where one sleeps in 90-minute bouts throughout the day and night, and why it is detrimental to overall health and productivity. Andrew Huberman agrees and advises listeners to sleep like an adult and get a solid 8 hours of sleep.

9. Viewing Morning SUNLight

Natural Light Benefits:Andrew and Matt discuss the importance of natural light for regulating the circadian rhythm and suggest getting at least 30-40 minutes of exposure to natural daylight early in the day. They also highlight that even on a cloudy day, natural sunlight is far more potent than indoor lighting.
Exercise and Sunlight:Matt and Andrew discuss the benefits of exercising and getting sunlight exposure early in the day for circadian rhythm alignment and sleep efficiency. They also bust myths about exercise timing during sleep and share studies on the positive effects of natural daylight exposure on sleep.

10. Caffeine

Caffeine Mechanisms:Andrew and Matt discuss how caffeine works as a psychoactive stimulant and its principal mode of action on adenosine. Adenosine is a chemical that accumulates in the brain and creates sleep pressure as we stay awake.
Sleep Pressure Mechanisms:Matt explains the concept of sleep pressure and how adenosine builds up in the brain throughout the day, causing us to feel sleepier as the evening approaches. He also discusses the two main receptors for adenosine and how they work to promote sleepiness and shut down wakefulness areas of the brain.
Caffeine's Effect:Matt and Andrew discuss the effects of caffeine on the brain and how it blocks adenosine receptors to prevent sleepiness. Caffeine essentially pulls out the chair from adenosine, preventing it from communicating to the brain that you've been awake for a long time.
Caffeine Crash:Matt and Andrew discuss the effects of caffeine on the adenosine receptor and how it can lead to a caffeine crash. They explain the half-life of caffeine and how it affects individuals differently. The conversation also touches on the dangers of assuming caffeine hasn't affected your sleep.
Caffeine and Sleep:Andrew and Matt discuss the effects of caffeine on sleep and the importance of cutting off caffeine intake at least 8-10 hours before bedtime to ensure deep, restorative sleep. They also touch on the dangers of caffeine dependency and the negative impact it can have on sleep quality.
Sleep Messaging:Matt and Andrew discuss the importance of sleep messaging in the public health sphere, and how to balance being faithful to the science while not scaring people who struggle with sleep. They also touch on the middle ground of achieving ideal circumstances and being gentle with ourselves when we deviate from them.

11. Alcohol

Alcohol and Sleep:Matt explains why alcohol is not a sleep aid and how it affects the brain's activity. Although alcohol can help people fall asleep faster, it does not promote naturalistic sleep.
Alcohol and Sleep:Matt Walker explains how alcohol affects the quality of sleep. Alcohol fragments sleep, reduces REM sleep, and can lead to emotional sensitivity. Even a single glass of wine with dinner can disrupt sleep.

12. Growth Hormone & Testosterone

Matt and Andrew discuss the impact of alcohol on growth hormone release during sleep and how disrupted REM sleep can affect the release of testosterone, which is important for overall well-being and tissue repair.

13. The Importance of REM Sleep

Matt Walker discusses the significance of REM sleep on emotional, hormonal, and cognitive health, as well as its linear relationship with longevity. Andrew Huberman compares the importance of REM sleep to the threshold level of movement needed for physical health.

14. Books vs. Podcasts

Andrew discusses the benefits of the podcast format, including the ability to provide regular updates and corrections. He encourages listeners to tune in for more insights on sleep and its various contours.

15. Lunchtime Alcohol

Andrew and Matt discuss the effects of alcohol on sleep and the importance of timing and dose. While Matt doesn't want to be puritanical, he offers some scientific information to empower people to make informed choices regarding their sleep and alcohol consumption.

16. Marijuana/CBD

Marijuana and Sleep:Matt explains that THC in marijuana can speed up the onset of non-consciousness, but it disrupts the architecture of sleep and blocks REM sleep. People using THC may not remember their dreams, but when they stop using it, they experience a rebound mechanism, leading to intense dreams.
Sleep and Substance Use:Matt and Andrew discuss how alcohol and THC affect sleep, specifically REM sleep. While alcohol can lead to intense periods of REM sleep, it also blocks it initially. THC builds up a debt for REM sleep and can lead to withdrawal dependency and rebound insomnia. Andrew and Matt also touch on the topic of addiction and dependency among regular pot smokers.
CBD and Sleep:Matt and Andrew discuss the effects of CBD on sleep quality and architecture. While there isn't enough data to make a definitive conclusion, low doses of CBD seem to promote wakefulness and higher doses may cause sedation. The purity of CBD supplements is also a concern, as many do not match the levels reported on the labels.
CBD and Sleep:Matt Walker discusses potential mechanisms behind how CBD may benefit sleep, including its thermoregulatory effects, anxiolytic properties, and ability to alter adenosine signaling. Andrew Huberman notes that CBD can be a bridge to discussing things that promote healthy sleep.

17. Melatonin

Melatonin and Sleep:Matt and Andrew discuss the role of melatonin in our sleep cycle, including how it's naturally produced in the body and how supplements compare to our endogenous levels. They also touch on the pineal gland as the source of melatonin.
Biological Clocks:Andrew and Matt discuss the pineal gland and its release of melatonin, which helps regulate our biological clocks. They explain how external factors such as daylight and temperature can reset our clocks to 24 hours, preventing us from drifting forward in time.
Melatonin and Sleep:Matt and Andrew discuss the role of melatonin in regulating sleep and whether or not melatonin supplements are effective for improving sleep. While melatonin helps with the timing of sleep, it doesn't necessarily aid in the generation of sleep itself. Studies suggest that melatonin supplementation is not particularly helpful for healthy adults and only increases total sleep time by an average of 3.9 minutes and sleep efficiency by 2.2%.
Melatonin's Sleep Benefits:Matt and Andrew discuss the effectiveness of melatonin as a sleep aid. While there is little evidence to support its benefits, it may help lower core body temperature and induce a sleepy state for some individuals.
Melatonin Benefits:Matt and Andrew discuss the benefits of melatonin supplementation, including its potential to help older adults with insomnia. They also touch on the importance of dropping core body temperature for better sleep and the dosages of melatonin supplements.
Melatonin Overdose:Matt and Andrew discuss the dangers of taking supra physiological doses of melatonin, which are often found in supplements. They explain that the optimal doses for sleep benefits are much lower than what is typically marketed and warn of potential negative effects on the body.
Hormone Supplementation:Andrew and Matt discuss the risks and benefits of hormone supplementation, specifically melatonin. They caution against taking high levels of hormones that can have detrimental effects on health, and emphasize the importance of understanding dosages and timing when taking supplements.

18. Magnesium

Andrew and Matt discuss the benefits of magnesium supplementation for sleep and the need for more studies to isolate the effects of specific forms of magnesium, such as magnesium bi glycinate and magnesium three and eight, which may have a higher capacity to cross the blood brain barrier and have a central nervous system effect. While magnesium deficiency can lead to sleep problems, the data on magnesium supplementation for healthy sleepers is not compelling.

19. Sleep Supplements

Sleep Supplements:Matt Walker discusses the effectiveness of valerian root as a sleep aid, citing studies that show little to no benefit. He also mentions the benefits of tart cherry and kiwi fruit, which can be taken as supplements or eaten as whole fruits.
Sleep and Tart Cherry:Matt Walker shares his research on the effects of tart cherry juice on sleep, revealing that it can increase sleep by up to 84 minutes and decrease daytime napping.
Tart Cherry Sleep Aid:Matt and Andrew discuss the potential benefits of tart cherry as a sleep aid and the misconceptions surrounding natural versus pharmaceutical remedies. While the data is still preliminary, Andrew finds it intriguing enough to experiment with himself, and mentions other supplements like Apigenin that have shown promising results.
Sleep Supplements:Andrew and Matt discuss the effectiveness of chamomile and apigenin as sleep supplements. Matt shares his approach to experimenting with supplements and emphasizes the importance of subjective and objective metrics. They also highlight the significance of considering behavioral tools and nutrition before turning to supplementation.
Sleep Optimization:Matt and Andrew discuss the benefits of cognitive behavioral therapy for insomnia over sleeping pills and the potential sleep benefits of kiwi fruit. They emphasize the importance of optimizing sleep through non-drug approaches and avoiding venturing into the use of supplements.
Sleep Benefits:Matt and Andrew discuss the sleep benefits of kiwi fruit and tart cherry, and how they can be attributed to the GABA system. They also touch on the potential role of tryptophan and serotonin in improving sleep.

20. Tryptophan & Serotonin

Andrew and Matt discuss the potential dangers of supplementing with serotonin and its precursor tryptophan for sleep. They explain the importance of the natural architecture of sleep and how serotonin needs to be modulated in specific ways during different stages of sleep. Artificially increasing serotonin levels at night could lead to the fragmentation of REM sleep.

21. Naps & Non-Sleep-Deep-Rest (NSDR)

Benefits of Napping:Matt Walker discusses the benefits of napping, including improved cardiovascular health, cortisol levels, learning and memory, and emotional regulation. Naps can be anywhere from 20 to 90 minutes, with a full cycle of non-REM and REM sleep being ideal.
The Power of Naps:Matt explains the benefits of napping and how even short naps can have potent effects on learning. However, he also warns about the dark side of naps and how they can disrupt our natural sleep cycle.
Napping Guidelines:Matt and Andrew discuss the potential dangers of napping and provide guidelines for those who want to nap. They advise against napping for people with insomnia and suggest limiting the nap time to 20-25 minutes to avoid going into the deepest stages of sleep. Matt also emphasizes that sleep is a right of human beings and no one should feel guilty about getting the sleep they need.

22. Sleep and Mortality

Too Much Sleep:Matt explains that hypersomnia, a condition where people have a high sleep need or sleep during the day, is often mistaken for sleeping too much. However, studies show that sleeping less than 7 hours predicts all cause mortality, but sleeping more than 9 hours can also lead to a shorter life.
Sleep and Mortality:Matt and Andrew discuss the relationship between sleep and mortality. They explore the idea that poor sleep quality may be the cause of longer sleep times, which have been associated with higher mortality rates. They also consider the possibility that there may be such a thing as too much sleep, just as there is with food, water, and oxygen.

23. Sleep and Sex

Sleep and Sex:Matt Walker and Andrew Huberman discuss the science behind the relationship between sex, orgasm, and sleep. They explore the sedative effects of prolactin and oxytocin, and how they contribute to better sleep quality. The data shows that sex resulting in orgasm can improve both subjective and objective sleep quality.
Sleep and Masturbation:Matt and Andrew discuss the benefits of masturbation on sleep and its hormonal effects. They also touch on the importance of open conversations about the topic.
Sleep and Sex:Matt and Andrew discuss how sleep affects sex and vice versa. Sleep disruption can lead to a decrease in reproductive hormones, menstrual cycle disruption, and a decrease in interest in sexual intimacy. Additionally, restless nights can lead to more brutal fights in relationships and a lower likelihood of resolving conflicts.
Sex and Testosterone:Andrew and Matt discuss the effects of sexual behavior on testosterone levels, including the impact of ejaculation and the importance of a healthy relationship. They highlight the role of the hypothalamus in regulating sleep and sex, emphasizing the profound effects of these behaviors on our biology.

24. Sleep Tips and Habits

Unconventional Sleep Tips:Matt Walker shares an unconventional tip for those who had a bad night of sleep - do nothing. Don't nap, sleep in, or consume extra caffeine to compensate. This will help you stick to your normal sleep schedule and avoid insomnia.
Sleep Recovery Tips:Matt Walker shares tips on how to recover from a bad night's sleep, including not sleeping in later, avoiding naps, and sticking to your normal bedtime, even after a bad night. He emphasizes the importance of staying in harmony with your natural sleep window and chronotype for best quality sleep.
Unconventional Sleep Tips:Matt and Andrew discuss unconventional tips for better sleep, including the importance of having a wind down routine and avoiding counting sheep. Sleep is a physiological process that requires gradual descent, and finding what works for you can make all the difference.
Better Sleep Habits:Matt and Andrew discuss the importance of getting a good night's sleep and share tips on how to achieve it. They talk about the benefits of taking a mental walk, writing down concerns in a worry journal, and the disproportionate difficulty and anxiety that comes with nighttime rumination. They also mention that keeping a worry journal can decrease the time it takes to fall asleep by 50%.
Unconventional Sleep Tips:Matt and Andrew discuss unconventional sleep tips such as removing all clock faces from the bedroom and not placing stock in worries and concerns. They also delve into the regulation of the autonomic nervous system and its impact on sleep.

25. Sleep Science Insights

Sleep Takeaways:Andrew and Matt discuss the positive and negative regulators of sleep. Matt shares valuable takeaways on the importance of sleep and how it affects our health. They also talk about the benefits of sharing scientific information with the public and being a sleep ambassador.
Sleep Science:Matt Walker discusses his work in sleep science and shares resources for those interested in learning more, including his website and his book Why We Sleep. He also hints at the possibility of starting a short-form podcast on the topic. Andrew Huberman expresses his admiration for Walker's work and encourages him to continue sharing his insights through various platforms.

26. Supplement Industry

Andrew discusses the issues with the supplement industry and how partnering with Thorn supplements can ensure the purity and accuracy of ingredients listed on the bottle. Listeners can get 20% off supplements at