The Matt Walker Podcast

In the second episode of our three-part series on chronotypes,  Matt speaks about what happens when you do not sleep in harmony with your natural chronotype. Unlike morning larks, night owls simply cannot fall asleep easily early at night, which leads to the first and most obvious consequence of not sleeping in line with your chronotype—you don’t sleep as much.Matt explains that morning types sleep over 7-hours per night on average, while evening types can only manage 6.6-hours of sleep per night. Matt also notes the upshot, which is a chronic “sleep debt”, one that accrues night after night, month after month. The ramifications are many, including increased caffeine intake for evening types, higher likelihood of developing hypertension and Type II Diabetes, and greater difficulty maintaining a healthy body weight. In addition to these consequences to the body, evening types are two to three times more likely to develop depression than their morning type counterparts, and twice as likely to be using antidepressants. Matt clarifies that his intent in sharing the concerning statistics is not to worry evening types, but rather, to help them realize their true biological nature, and as important, not feel guilty for it. Today’s episode aims to vindicate and empower evening types with the knowledge that they may be sleep deprived, and to help them find a schedule that falls in line with their natural chronotype.Matt Finally speaks about current societal practices that push (actually, force) night owls into unhealthy sleep rhythms. He outlines his (lofty 😊) goal of restructuring the typical schedule of work in first-world nations, which is strongly biased toward early start times that incorrectly punish night owls and favor morning larks. Matt notes that this is markedly unfair, since it is not their choice as to which ‘type’ they are. Instead, it is their pre-ordained, genetic-based sleep chronotype, yet society wrongly assumes that evening types could get up earlier if only they weren’t so slovenly. Of course, the science and this episode tells us otherwise.The episode is sponsored by the wonderful folks over at Athletic Greens, who are providing a discount and free product if you use the link above. Athletic Greens is a comprehensive daily nutritional beverage containing 75 vitamins, minerals, and whole food-sourced ingredients, including a multivitamin, multimineral, probiotic.So, head on over to Athletic Greens www.athleticgreens.com/mattwalker and get a free year supply of Vitamin D and 5 free travel packs today. Finally, if you have thoughts or feedback you’d like to share, please reach out on Instagram @drmattwalker.Basic Resources Discover your chronotype: AutoMEQ: Automated Morningness-Eveningness Questionnaire (AutoMEQ)Scientific Review: Biological Rhythm and ChronotypeScientific Review: Chronotype and Mental Health: Recent Advances

Episode 04: Chronotype: Part 1SummaryAre you a morning type? Or are you an evening type? Perhaps you are neither of the two? Today’s episode is the first in a three-part series all about your chronotype, or your body’s natural biological preference to be awake and be asleep at a certain time. Matt begins by explaining exactly what your chronotype is, then breaks down the three main “flavors” of chronotype (morning lark, night owl, or somewhere in-between). In addition, and listed in the show notes, below, he explains how to determine whether you are a night owl or a morning lark. He will also describe how an individual’s sex falls into the equation and the difference between your chronotype and your circadian rhythm. You’ll hear about the key ways in which evening types biologically differ from morning types, that your chronotype isn’t your own choice nor is it your own fault, but rather, there is a very strong genetic basis of why and how you are programmed in terms of being a morning or an evening type? Today’s main takeaway is that when you or when society tries to force you to sleep in opposition to your biology, there can be unfortunate consequences. Stay tuned as we explore these in greater detail next time.The episode is sponsored by the wonderful folks over at Athletic Greens, who are providing a discount and free product if you use the link above. Athletic Greens is a comprehensive daily nutritional beverage containing 75 vitamins, minerals, and whole food-sourced ingredients, including a multivitamin, multimineral, probiotic. So, head on over to Athletic Greens www.athleticgreens.com/mattwalker and get a free year supply of Vitamin D and 5 free travel packs today. Finally, if you have thoughts or feedback you’d like to share, please reach out on Instagram @drmattwalker.Basic Resources Discover your chronotype: AutoMEQ: Automated Morningness-Eveningness Questionnaire (AutoMEQ)Scientific Review: Biological Rhythm and ChronotypeScientific Review: Chronotype and Mental Health: Recent Advances

#03 Circadian RhythmsContinuing on from last week’s episode about sleep pressure, today, Matt Walker dives into the second half of the sleep-wake story, circadian rhythm. Matt explains that your circadian rhythm, or your 24-hour internal clock, begins drumming out its loud activating beat just before you wake in the morning and gets louder throughout the day, peaking in the early afternoon and hitting its lowest point in the middle of your sleep phase overnight. Matt describes how circadian rhythm and sleep pressure work independently of one another, yet coincide with a beautiful synchronicity to naturally and gently rouse you from sleep in the morning and rouse you into full wakefulness, then pull you into a wonderful, restorative sleep at night. You’ll also hear about the reliable mid-afternoon drop in alertness we see each day, what this means in terms of how humans were designed to sleep, and why it may explain the occasional need for a siesta._________________The episode is sponsored by the wonderful folks over at Athletic Greens, who are providing a discount and free product if you use the link above. Athletic Greens is a comprehensive daily nutritional beverage containing 75 vitamins, minerals, and whole food-sourced ingredients, including a multivitamin, multimineral, probiotic. So, head on over to  www.athleticgreens.com/mattwalker and get a free year supply of Vitamin D and 5 free travel packs today. Finally, if you have thoughts on sleep topics that you want Matt to cover, or you have feedback you’d like to share so he can be better at podcasting, please reach out to Matt on Instagram @drmattwalker. He'd love to hear from you🤗!

Episode 02:  Sleep PressureWelcome back to the Matt Walker podcast. Today’s episode looks at the story of sleep pressure - how it works, how you can try to block it or fool it, and why you feel so good after a night of full, peaceful sleep. Matt explains that from the moment you wake up, a chemical called adenosine begins to build up in your body. The longer you’re awake, the more adenosine will build up and the sleepier you will feel. This is called sleep pressure. Once adenosine concentrations peak, usually after about 12-16 hours of being awake, the irresistible urge for slumber takes hold. Sleep then purges the buildup of adenosine in your brain, and you will wake feeling refreshed and ready to face another day.Today, you’ll learn about the dual-action effect of adenosine, how caffeine operates to artificially mute its “sleepiness” signals to the brain, and the ideal length of sleep you need to fully clear the adenosine levels from your body overnight. The episode is sponsored by the wonderful folks over at Athletic Greens, who are providing a discount and free product if you use the link above. Matt is more than a little obsessed with Athletic Greens. He's been using Athletic Greens, each day for the past 3 years (and he does buy his own to prevent any conflict of interest, as that's important to integrity). Why does Matt use it each day.? Athletic Greens is a comprehensive daily nutritional beverage containing 75 vitamins, minerals, and whole food-sourced ingredients, including a multivitamin, multimineral, probiotic. So, head on over to  www.athleticgreens.com/mattwalker and get a free year supply of Vitamin D and 5 free travel packs today. Finally, if you have thoughts or feedback you’d like to share, please reach out on Instagram @drmattwalker.Music credit:By the incredible, Kai Engel (aka Anton Fedchenkov).

Episode 01:  HighlightsHuman sleep has been separated into two main types: Non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleepNREM sleep is further divided into four stages, with each stage increasing in their depth of sleepREM sleep is named this way because of the bizarre, horizontal, shuttling eye movements that occur underneath your eyelids during this stage of sleepREM sleep is the principal stage in which we dream, although it can occur in the other stages as wellNREM and REM sleep play out in a battle for brain domination throughout the nightThis cerebral war is going to be won and lost every 90 minutes, creating the standard cycling architecture of sleep for humansOther species may have a slightly different NREM to REM cycles, with birds experiencing a cycle that only lasts about 4-5 minutes, and giraffes about 24 minutesDuring NREM sleep, we see bursts of deeply powerful brain waves that flow over your cortexWe also see sleep spindles, which are short, synchronous bursts of electrical brain wave activity that last for about 1-1.5 secondsAbout 60-70 minutes into your first sleep cycle, your brain starts to rise up again into later stages of NREM sleep, then pop into a short REM sleep period, back to NREM sleep, then returning to REM sleep once againYour brain goes through this cycle every 90 minutesWhat changes is the ratio of NREM to REM sleep as you move through the night, with your sleep cycle comprised of more REM sleep during the second half of the nightIf you wake up two hours earlier than usual, you aren’t just losing 2 hours of sleep - you could be losing 50, 60, or even 70% of your REM sleepAll stages of sleep are critical and perform different functions for the brain and body at different times of nightEpisode Sponsor:This episode is sponsored by Athletic Greens, who are providing a discount and free product if you use the link above. Athletic Greens is a comprehensive daily nutritional beverage containing 75 vitamins, minerals, and whole food-sourced ingredients, including a multivitamin, multimineral, probiotic. So, head on over to www.athleticgreens.com/mattwalker and get a free year supply of Vitamin D and 5 free travel packs today. Feedback: Please visit Matt on Instagram and tell him what he can be doing to make these podcasts better, and let him know what topics you want him to cover next! Links:Brain Basics: Understanding Sleep | National Institute of Neurological Disorders and StrokeMusic credit:By the incredible, Kai Engel (aka Anton Fedchenkov).

The Matt Walker Podcast is all about sleep, the brain, and the body  ·  Matt is 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.