Stay ConnectedThe Matt Walker Podcast is all about sleep, the brain, and the body. Matt is a Professor of Neuroscience at the University of California, Berkeley. He is the author of the book, Why We Sleep and has given a few TED talks. Matt is an awkward British nerd who adores science and the communication of science to the public.
Want to sleep better alongside others doing the same? Come join my Art of Sleep community: skool.com/art-of-sleep
Copyright: © 2025 The Matt Walker Podcast
Want to sleep better alongside others doing the same? Come join my Art of Sleep community: skool.com/art-of-sleep
Today, Matt explores the fascinating realm of nightmares and the cutting-edge treatment known as Image Rehearsal Therapy (IRT). Nightmares, often associated with rapid eye movement sleep (REM sleep), can disrupt sleep quality and emotional well-being. However, IRT offers a unique approach to tackling nightmares by helping individuals envision alternative endings to their recurring dreams. By modifying and rehearsing these alternative scenarios, individuals can update their nightmare memories with more neutral or positive experiences.
Delving into the science behind IRT, Matt showcases its potential to significantly reduce the frequency and severity of nightmares. Furthermore, he shares a groundbreaking study that investigates the use of sound cues during dream sleep to enhance the efficacy of IRT. The study's findings suggest that combining daytime rehearsal with nighttime memory reactivation could lead to even greater psychological improvement and long-lasting therapeutic benefits. As Matt concludes, while the study represents a promising step forward, further research is needed to fully explore the potential of this innovative approach to nightmare treatment.
Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.
The good people at InsideTracker are one of the sponsors of this week's episode, and they are generously offering a special 25% off any one of their programs for anyone who uses the above link during the time window of this episode. InsideTracker is a personalized biometric platform that analyzes your blood and your DNA to better understand what's happening inside of you and offers suggestions regarding things that you can do to better try and adjust some of those numbers, optimize them, and, as a result, optimize you.
Another sponsor this week is the biochemical electrolyte drink company LMNT, and they are very kindly offering eight free sample packs when you purchase any one of their orders at drinklmnt.com/mattwalker. LMNT is an electrolyte sports drink that I can get behind - it's created from the basis of science, and it has no sugar, no coloring, and no artificial ingredients – all qualities that are so important to maintaining your blood biochemical balance. If you want to give LMNT a try, just head on over to drinklmnt.com/mattwalker and get your eight free samples with your first purchase.
As always, if you have thoughts or feedback you’d like to share, please reach out to Matt on Instagram.
Want to sleep better alongside others doing the same? Come join my Art of Sleep community: skool.com/art-of-sleep
In today’s episode, Matt discusses the sleep disorder known as sleep apnea, focusing on its definition, prevalence, and the dangers it poses if left untreated. Sleep apnea is a breathing-related sleep disorder, with obstructive sleep apnea being the most common form. It occurs when the airway partially or fully collapses during sleep, leading to disrupted breathing and oxygen deprivation. Sleep apnea is alarmingly prevalent, affecting an estimated 12-20% of the population worldwide, with a higher risk for males, overweight individuals, smokers, and those leading sedentary lifestyles.
The consequences of untreated sleep apnea can be severe, including an increased risk of developing dementia, cardiovascular disease, diabetes, and even a higher likelihood of falling asleep while driving. Matt emphasizes the importance of diagnosis and offers insights into clinical assessment methods, such as screening questionnaires and sleep recordings, to determine the presence and severity of sleep apnea. Treatment options include Continuous Positive Airway Pressure (CPAP) devices, mandibular advancement devices, and in extreme cases, surgical intervention. In the end, Matt urges listeners to prioritize their sleep health, seek help, get tested, receive appropriate treatment to improve their quality of life, and potentially extend their lifespan along the way.
Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.
The good people at InsideTracker are one of the sponsors of this week's episode, and they are generously offering a special 25% off any one of their programs for anyone who uses the above link during the time window of this episode. InsideTracker is a personalized biometric platform that analyzes your blood and your DNA to better understand what's happening inside of you and offers suggestions regarding things that you can do to better try and adjust some of those numbers, optimize them, and, as a result, optimize you.
Also sponsoring this week are those fine people at Athletic Greens, and they are generously offering 3 benefits for anyone who uses the above link for their first order: 1) a discount on your order; 2) a one-year free supply of vitamin D; 3) five free travel packs. Athletic Greens is a nutrition drink that combines a full complement of antioxidants, minerals, and biotics, together with essential vitamins. Matt’s been using it for several years now because he’s serious about his health, and because he did his research on the science and ingredients in Athletic Greens and thinks its scientific data can be taken as ground truth.
As always, if you have thoughts or feedback you’d like to share, please reach out to Matt on Instagram.
Want to sleep better alongside others doing the same? Come join my Art of Sleep community: skool.com/art-of-sleep
This week, Matt introduces a new segment called "Hot Off the Press," where he covers the latest and most exciting studies in sleep science. And the topic of discussion for this first installment is a great one: excessive slumber - exploring the questions of whether one is getting enough sleep and if there is such a thing as too much sleep. Listen in today to find out if too much sleep can be harmful in the same way that too little sleep is, whether or not there may be an upper limit to the benefits of sleep, or if further research is necessary to provide a conclusive answer to either of these crucial questions.
Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.
The good people at InsideTracker are one of the sponsors of this week's episode, and they are generously offering a special 25% off any one of their programs for anyone who uses the above link during the time window of this episode. InsideTracker is a personalized biometric platform that analyzes your blood and your DNA to better understand what's happening inside of you and offers suggestions regarding things that you can do to better try and adjust some of those numbers, optimize them, and, as a result, optimize you.
Another sponsor this week is the biochemical electrolyte drink company LMNT, and they are very kindly offering eight free sample packs when you purchase any one of their orders at drinklmnt.com/mattwalker. LMNT is an electrolyte sports drink that I can get behind - it's created from the basis of science, and it has no sugar, no coloring, and no artificial ingredients – all qualities that are so important to maintaining your blood biochemical balance. If you want to give LMNT a try, just head on over to drinklmnt.com/mattwalker and get your eight free samples with your first purchase.
As always, if you have thoughts or feedback you’d like to share, please reach out to Matt on Instagram.
Want to sleep better alongside others doing the same? Come join my Art of Sleep community: skool.com/art-of-sleep
Matt returns with Dr. Craig Kanapari to discuss sleep in teens and how biological and hormonal changes occur at a young age, usually around 11-13. The most clear determinant of sleep duration in a teen is wake time, and enforcing a wake time inappropriate to the teen's natural sleep period can lead to insomnia-like symptoms and create conflict. The single greatest threat to a teen's sleep schedule is early high school start times. California recently signed a law to address this, and other states are beginning to follow suit.
They also discuss teenage sleep deprivation and the issues it leads to. They also explore the concept of social jet lag as well as how teens often have their own devices and are allowed to keep their phones in their rooms. The conversation continues with the effects of chronic sleep deprivation on teenagers, including on academic performance and psychological effects such as depression and anxiety, as well as the health and safety implications, such as increased risk of car accidents.
Lastly, they recount the relationship between kids and ADHD, sleep deprivation, and medication. Specifically how teens not getting enough sleep can masquerade as ADHD, how stimulants used to treat ADHD can affect nighttime sleep, and the issue of hypersomnia. It suggests that parents look out for their children's sleep duration and snoring, and if their child is struggling, not to forget about sleep as it is important for their health and wellbeing.
Want to sleep better alongside others doing the same? Come join my Art of Sleep community: skool.com/art-of-sleep
Today Matt’s discussion with Dr. Craig Canapari continues, delving into the major changes in sleep that a child will go through from the ages of one to ten. This includes how regularity and appropriate sleep opportunities are important for getting good sleep, and potential medical issues that can arise from not getting enough sleep, such as snoring and restless leg disorder. They also discuss when during child development it can be wise to reduce napping and switch to monophasic (single nighttime) sleep bouts, and expectations around the transition from a crib to a bed, which often happens around ages 2-4 years.
Added to this is a conversation about how to deal with struggles with getting your child down for the night. One effective method is changing the *timing* of bedtime, often trying to make it a little earlier, which can result in more sleep for your child. Dr. Canapari also brings attention to the clear and significant sleep disparities that exist across socioeconomic lines in both adults and children. They emphasize the importance of paying attention to the red flags of behavioral issues, falling asleep easily, and hyperactivity which can indicate insufficient sleep.
Matt and Craig discuss the increasing use of melatonin as a sleep aid in children over the past decade and address safety concerns, highlighting that it can be an appropriate intervention if used with caution and in conjunction with a behavioral plan. Finally, Dr. Canapari reminds us that snoring in a child should not be ignored. It can be a sign of obstructive sleep apnea, which can be holding your child back.
Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.
The good people at InsideTracker are one of the sponsors of this week's episode, and they are generously offering a special 25% off any one of their programs for anyone who uses the above link during the time window of this episode. InsideTracker is a personalized biometric platform that analyzes your blood and your DNA to better understand what's happening inside of you and offers suggestions regarding things that you can do to better try and adjust some of those numbers, optimize them, and, as a result, optimize you.
Another sponsor this week is the biochemical electrolyte drink company LMNT, and they are very kindly offering eight free sample packs when you purchase any one of their orders at drinklmnt.com/mattwalker. LMNT is an electrolyte sports drink that I can get behind - it's created from the basis of science, and it has no sugar, no coloring, and no artificial ingredients – all qualities that are so important to maintaining your blood biochemical balance. If you want to give LMNT a try, just head on over to drinklmnt.com/mattwalker and get your eight free samples with your first purchase.
As always, if you have thoughts or feedback you’d like to share, please reach out to Matt on Instagram.
Links for Dr. Canapari:
Book: https://a.co/d/07SDrVn
Twitter: https://twitter.com/DrCanapari
Web: sleek.bio/canapari
TikTok: https://vm.tiktok.com/ZMemf3exT/
Instagram: https://www.instagram.com/drcanapari/
Want to sleep better alongside others doing the same? Come join my Art of Sleep community: skool.com/art-of-sleep
Today Matt’s discussion with Dr. Craig Canapari continues, as they delve into the science behind sleep training. Together they cover what it is and when it may be an appropriate technique. Dr. Craig Canipari provides an overview of the different methods of sleep training - ranging from simple bedtime routines, to extinction (also known as cry it out) - as well as some of the historical context behind the technique, and also the controversies and alternatives. It is such a personal choice, and different people feel comfortable with different methods. Dr. Canipari also discusses time restricted eating for your infant, and the importance of considering the long-term effects of sleep deprivation on parents.
Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.
The good people at InsideTracker are one of the sponsors of this week's episode, and they are generously offering a special 25% off any one of their programs for anyone who uses the above link during the time window of this episode. InsideTracker is a personalized biometric platform that analyzes your blood and your DNA to better understand what's happening inside of you and offers suggestions regarding things that you can do to better try and adjust some of those numbers, optimize them, and, as a result, optimize you.
Also sponsoring this week are those fine people at Athletic Greens, and they are generously offering 3 benefits for anyone who uses the above link for their first order: 1) a discount on your order; 2) a one-year free supply of vitamin D; 3) five free travel packs. Athletic Greens is a nutrition drink that combines a full complement of antioxidants, minerals, and biotics, together with essential vitamins. Matt’s been using it for several years now because he’s serious about his health, and because he did his research on the science and ingredients in Athletic Greens and thinks its scientific data can be taken as ground truth.
As always, if you have thoughts or feedback you’d like to share, please reach out to Matt on Instagram.
Links for Dr. Canapari:
Book: https://a.co/d/07SDrVn
Twitter: https://twitter.com/DrCanapari
Web: sleek.bio/canapari
TikTok: https://vm.tiktok.com/ZMemf3exT/
Instagram: https://www.instagram.com/drcanapari/
FB: https://www.facebook.com/CraigCanapariMd/
Want to sleep better alongside others doing the same? Come join my Art of Sleep community: skool.com/art-of-sleep
Today Matt begins a new series all about sleep in infants, in kids, in teenagers, and in parents. He is joined by Dr. Craig Canapari one of the world leaders in pediatric sleep medicine. Dr. Canapari has also written a fantastic book on sleep for babies, kids and parents called, It's Never Too Late to Sleep Train. Enjoy the first episode in a new series, with some show highlights below!
Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.
The good people at InsideTracker are one of the sponsors of this week's episode, and they are generously offering a special 25% off any one of their programs for anyone who uses the above link during the time window of this episode. InsideTracker is a personalized biometric platform that analyzes your blood and your DNA to better understand what's happening inside of you and offers suggestions regarding things that you can do to better try and adjust some of those numbers, optimize them, and, as a result, optimize you.
Today's podcast is also supported by biochemical electrolyte drink company LMNT, and they are very kindly offering eight free sample packs when you purchase any one of their orders at drinklmnt.com/mattwalker. LMNT is an electrolyte sports drink that I can get behind - it's created from the basis of science, and it has no sugar, no coloring, and no artificial ingredients – all qualities that are so important to maintaining your blood biochemical balance. If you want to give LMNT a try, just head on over to drinklmnt.com/mattwalker and get your eight free samples with your first purchase.
And, as always, if you have thoughts or feedback you’d like to share, please reach out to Matt on Instagram.
Links for Dr. Canapari:
Book: https://a.co/d/07SDrVn
Twitter: https://twitter.com/DrCanapari
Web: sleek.bio/canapari
TikTok: https://vm.tiktok.com/ZMemf3exT/
Instagram: https://www.instagram.com/drcanapari/
FB: https://www.facebook.com/CraigCanapariMd/
Want to sleep better alongside others doing the same? Come join my Art of Sleep community: skool.com/art-of-sleep
On today’s episode, Matt goes beyond the if and the what type of exercise to discuss the when. Which is to say, does the timing of exercise matter when it comes to sleep improvements? Based on his experience working on insomnia, Matt would previously have recommended avoiding mid-to-late evening exercise as the resulting rise in core temperature could harm your chances for good sleep. However, it’s since been discovered that the evidence is quite the contrary, mostly allowing us to abandon the myth of evening exercise as the archenemy of good sleep.
But how late is late? How close to bedtime can exercise be done before things actually break? Studies have shown that exercise 3.5 hours before bed boosts sleep by fifteen minutes and significantly reduces the amount of time spent awake at night, while individuals who did weightlifting or resistance training two hours before bed fell asleep in half the time it would normally take and experienced an almost 20% boost in deep non-REM sleep in the first few hours of the night. Getting even closer to bed, an all-men study showed that neither cardio nor weight/resistance training ninety minutes before bed did any damage to sleep (though there was no marked sleep improvement either). But at sixty minutes, there was an impact—a reduction in the total amount and overall efficiency of sleep. Therefore, it seems that exercise before bed will more than likely result in very enviable sleep benefits, so long as it’s done more than an hour before bed (and ideally ninety minutes before).
In addition, it’s been discovered that exercising across different times of day can make a difference to the amount of at least three specific sleep features: REM sleep, light non-REM sleep, and time spent tossing and turning awake at night. First, exercising in the middle part of the day (i.e. three to eight hours before bed) is associated with moderately less REM sleep. Second, morning or evening exercise provides the nice benefit of spending less time in less-restorative, light non-REM sleep. And third, working out in the evening (at least three hours before bedtime) leads to more efficient sleep and less tossing and turning.
Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.
The good people at InsideTracker are one of the sponsors of this week's episode, and they are generously offering a special 25% off any one of their programs for anyone who uses the above link during the time window of this episode. InsideTracker is a personalized biometric platform that analyzes your blood and your DNA to better understand what's happening inside of you and offers suggestions regarding things that you can do to better try and adjust some of those numbers, optimize them, and, as a result, optimize you.
Also sponsoring this week are those fine people at Athletic Greens, and they are generously offering 3 benefits for anyone who uses the above link for their first order: 1) a discount on your order; 2) a one-year free supply of vitamin D; 3) five free travel packs. Athletic Greens is a nutrition drink that combines a full complement of antioxidants, minerals, and biotics, together with essential vitamins. Matt’s been using it for several years now because he’s serious about his health, and because he did his research on the science and ingredients in Athletic Greens and thinks its scientific data can be taken as ground truth.
As always, if you have thoughts or feedback you’d like to share, please reach out to Matt on Instagram.
Want to sleep better alongside others doing the same? Come join my Art of Sleep community: skool.com/art-of-sleep
Today, Matt focuses on how the type, intensity, and duration of exercise affect its impact on sleep. A study of middle-aged adults split its active group into three subgroups: moderate-intensity aerobic exercise, high-intensity aerobic exercise, and moderate-to-intense weight/resistance training. The groups performing aerobic exercise got more beneficial sleep effects, while surprisingly, the greatest improvement was in the moderate rather than the high-intensity group. These findings replicate those from the National Sleep Survey, indicating a Goldilocks syndrome in finding just the right level of exercise to benefit sleep.
Regarding types of exercise, studies show that cycling produces the most robust improvements in deep non-REM sleep. Meanwhile, more mind-body-based exercises provide equal if not greater benefits in sleep quality than traditional forms of physical activity.
Another factor to consider is duration of exercise. Some studies have discovered that more minutes of acute exercise in a single bout produce larger benefits in several sleep metrics, including deep non-REM sleep, the speed of falling asleep, and the amount of sleep overall. However, it’s also been found that progressively longer bouts of exercise can be associated with a moderate reduction in the amount of REM sleep, though Matt states that it’s such a modest reduction as not to be concerning.
The final element is the intensity of exercise. Early studies found indications that more intense exercise gave a greater improvement in sleep quality, though the difference in improvement was minimal. Later, more comprehensive studies have reinforced this, indicating that it is not necessary to go to the extremes of physical exertion to get most of the sleep benefits exercise provides.
Currently, the reason why exercise promotes better sleep is unknown, but Matt offers several tenable possibilities, including that exercise promotes the release of immune factors and growth hormone. He also suggests a more “out there” explanation in the form of a chemical called brain-derived neurotrophic factor (BDNF), the release of which is facilitated by exercise, and which is known to increase deep non-REM sleep.
Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.
Today's podcast is supported by InsideTracker, and they are generously offering a special 25% off any one of their programs for anyone who uses the above link. InsideTracker is a personalized biometric platform that analyzes your blood and your DNA to better understand what's happening inside of you and also offers suggestions regarding things that you can do to better try and adjust some of those numbers, optimize them, and, as a result, optimize you.
Another sponsor this week is the biochemical electrolyte drink company LMNT, and they are very kindly offering eight free sample packs when you purchase any one of their orders at drinklmnt.com/mattwalker. LMNT is an electrolyte sports drink that I can get behind - it's created from the basis of science, and it has no sugar, no coloring, and no artificial ingredients – all qualities that are so important to maintaining your blood biochemical balance. If you want to give LMNT a try, just head on over to drinklmnt.com/mattwalker and get your eight free samples with your first purchase.
And, as always, if you have thoughts or feedback you’d like to share, please reach out to Matt on Instagram.
Want to sleep better alongside others doing the same? Come join my Art of Sleep community: skool.com/art-of-sleep
This week, Matt goes deeper into the relationship between sleep and exercise. More specifically, does daytime exercise change the stages and types of sleep? Deep sleep is critical for various functions, so anything that can increase it is desirable. Older adults have an inherently difficult time generating deep non-REM sleep; however, a study showed that the amount can shoot up by 40% following a day with modest exercise. Moreover, it indicated that participants’ cognitive functioning was significantly sharper following that night of exercise-enhanced deep sleep.
Exercise in healthy young adults also stimulates a lush increase in deep non-REM slow brainwave activity, up to 50% in the first part of the night. However, that exercise must be more vigorous to see a consistent, substantive, increase in deep non-REM sleep.
However, there is a footnote to this good news: most of these studies saw a modest but reliable decrease in the amount of REM sleep the night following exercise. This isn’t a surprise for sleep scientists like Matt, who were already aware of some reciprocity between these two types of sleep, which seem to push and pull at each other’s levels. Why this reduction in REM sleep happens with a dose of acute, one-shot exercise and what the consequences are remains unexplored. Matt’s hypothesis is that it occurs because, in many of these studies, the total amount of time in bed is fixed. He suspects that if individuals were left to sleep as much as they wanted, they would sleep a little longer and thereby get the same amount or even more REM sleep.
Ultimately, the question becomes this: is regular exercise effective for maintaining and improving good sleep, or does its potency gradually wear off ? Thankfully, the answer is that regular, consistent exercise does benefit sleep, and the improvements it provides don’t get fade over time. Indeed, a meta-analysis approach teaches us that regular exercise has four persistent benefits, 1) improving sleep efficiency, 2) an increase in the amount of sleep achieved, 3) an increase in the speed of falling asleep, and 4) improvement in the quality of sleep experienced.
Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.
The good people at InsideTracker are one of the sponsors of this week's episode, and they are generously offering a special 25% off any one of their programs for anyone who uses the above link during the time window of this episode. InsideTracker is a personalized biometric platform that analyzes your blood and your DNA to better understand what's happening inside of you and offers suggestions regarding things that you can do to better try and adjust some of those numbers, optimize them, and, as a result, optimize you.
Also sponsoring this week are those fine people at Athletic Greens, and they are generously offering 3 benefits for anyone who uses the above link for their first order: 1) a discount on your order; 2) a one-year free supply of vitamin D; 3) five free travel packs. Athletic Greens is a nutrition drink that combines a full complement of antioxidants, minerals, and biotics, together with essential vitamins. Matt’s been using it for several years now because he’s serious about his health, and because he did his research on the science and ingredients in Athletic Greens and thinks its scientific data can be taken as ground truth.
As always, if you have thoughts or feedback you’d like to share, please reach out to Matt on Instagram.
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