Professor Sara C. Mednick is a cognitive neuroscientist at the University of California, Irvine and author of The Hidden Power of the Downstate (Hachette Go!, pub date: April, 2022) and Take a Nap! Change Your Life. (Workman). She is passionate about understanding how the brain works through her research into sleep and the autonomic nervous system. Dr. Mednick’s seven-bedroom sleep lab works literally around-the-clock to discover methods for boosting cognition by napping, stimulating the brain with electricity, sound and light, and pharmacology. Her lab also investigates how the menstrual cycle and aging affect the brain. Her science has been continuously federally funded (National Institute of Health, National Science Foundation, Department of Defense Office of Naval Research, DARPA).
Dr. Mednick was awarded the Office Naval Research Young Investigator Award in 2015. Her research findings have been published in such leading scientific journals as Nature Neuroscience and The Proceedings from the National Academy of Science, and covered by all major media outlets. She received a BA from Bard College, Annandale-on-Hudson, NY, in Drama/Dance. After college, her experience working in the psychiatry department at Bellevue Hospital in New York, inspired her to study the brain and how to make humans smarter through better sleep. She received a PhD in Psychology from Harvard University, and then completed a postdoc at the Salk Institute for Biological Studies and UC San Diego. She resides in San Diego, CA.
Please enjoy my conversation with Sara Mednick.
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Follow Along with the Transcript – Episode 125
Sara Mednick 0:00
So people who are super meditators definitely sleep less hours and that is you know, documented multiple times.
Alex Ferrari 0:22
I've been able to partner with Mindvalley to present you guys FREE Masterclass is between 60 and 90 minutes, covering Mind Body Soul Relationships and Conscious Entrepreneurship, taught by spiritual masters, yogi's spiritual thought leaders and best selling authors. Just head over to nextlevelsoul.com/free. I'd like to welcome to the show Sara Mednick. How you doing Sara?
Sara Mednick 0:55
Hey, nice to meet you.
Alex Ferrari 0:56
Pleasure to meet you as well. Thank you so much for coming on the show. I'm I'm excited to talk about your new book, The Power of the downstate and talk about sleep and talk about how we can use it and what happens to our brains and when to eat and when not to eat and when to go to sleep or when not to go to sleep? And how many hours do we really need. There's a lot of myth about sleep a lot of wives tales about like how much sleep you need and things you hear. So I want to hear it straight from the from the net, the horse's mouth, but from the professionals mouth. So my first question is, how did you get your start your journey into understanding sleep and, and restoring energy from sleep and all that kind of good stuff?
Sara Mednick 1:38
You know, do you want the long version or the short version?
Alex Ferrari 1:40
The short one we'll be fine.
Sara Mednick 1:43
I was in you know, when I finally got to graduate school, I just went to a lecture by a guy named Robert stick Gould, who was starting to do a new form of sleep research, where he was able to actually put together a new way of studying the benefits of sleep for cognition. And it was so interesting and exciting that I thought, and he's also such a kind of wacky guy that I thought this is a guy I could work with. So we started talking. And he was always doing nighttime sleep. And he showed that you needed to have at least six to eight hours of nighttime sleep to show any benefits from a full night of sleep. But I had many people I knew who were nappers including my dad, who was very, very dedicated Napper. And he would sleep for 20 minutes to an hour and wake up and be a new man. Well, that doesn't make any sense, right? How can we have this daytime period in the middle of the day? That makes us feel wonderful. But if we slept for just one hour in the middle of the night, we feel terrible, right? So it got me questioning this idea of naps. And what was so special about naps. And that's how I I built a little nap lab in the Harvard psychology department. And then from there, we just moved on to deeper understanding of the roles of sleep in a whole bunch of, you know, not just cognition, but also health. And then what's trying you know, what's going on when we sleep. And then that gave me this insight into the autonomic nervous system and, and it's just flown from there.
Alex Ferrari 3:19
So what is the downstate?
Sara Mednick 3:21
Yeah, the downstate is a term I came up with that actually borrow from science. And it summarizes or encapsulates all of the restorative activities and processes that we need to engage in on a daily basis, both during the day and the night, to make sure that we have the most amount of resources possible that we've replenished all of our resources. And we're ready for the next go time, which I call the Upstate. Because we're rhythmic animals. We go from upstate to downstate, from upstate to downstate.
Alex Ferrari 3:52
So we're, and I guess this goes back to when we were hunter and gatherers. I mean, we needed to restore our bodies, our minds things to be able to go back out and hunt. You can't hunt 24 hours, 48 hours straight, you have to have a restful period. And this seems to be something within nature, there's a cycle in nature, even if it's the seasons, there seems to always be a restorative state. And a downstate so fall and winter would be a downstate and an Upstate would be spring in summer. Is that a fair statement?
Sara Mednick 4:24
You're singing my song. That's exactly right is if you start to see the world in rhythms, you realize that everything is rhythmic. Any living animal has these rhythms of activity and repose. And the repose isn't just a period where you're just you know, dead. You basically are doing all of the replenishing work repairing because you know, the Upstate is very stressful, right? This is where all of our stress occurs. This is where we do our exercise. So we tear our muscles at that point, right but we also make all these like new thoughts in our heads. We experience a lot of stressful experiences. And all of that creates a lot of wear and tear in our brains and our bodies, and our heart systems and our, our metabolism, you know, our guts, all of these places feel that stress. And so we need to go through periods where we can replenish that. But then also process it, you know, process the emotions and process the stress. So that then when we get to the next day, or the next moment, we've calmed ourselves down enough and restored ourselves enough that we're ready for the next day.
Alex Ferrari 5:35
So why is it then that certain people can function on a five to six hour cycle comfortably during the day, and others need eight hours, seven to eight hours a day. And it's, it doesn't seem like a lot of time. But boy, that extra hour does add up, trust me. I know. I mean, sometimes my body won't even let me sleep past seven hours, it just wakes up automatically, because it's that's my rhythm. I'm an early riser, I go to bed around 10 Because I'm an old man, but and then I wake up around five every morning to go to the gym or to meditate or to work or something along those lines. So that's generally I get around between six, seven, like five, it's solid six hours, sometimes it can grow into seven hours. And I function and sometimes I've I've gone months, months going five hours sleep, and I function fine. But other people need eight hours. And I don't even know. I'm just telling you my experience of sleep. Everyone I'm sure everybody who talks to you talks about? Well, I only need two hours of sleep. What is the science behind what we actually need? And is it a case by case basis?
Sara Mednick 6:52
Yeah, you know that everybody's sleep is different, as you said, right. So there are some genetic differences between people. And their different groups of people. Some people are what we call short sleepers. And it sounds like you might be one of them were five hours, even sometimes people say four hours can be enough for them to do really well. And they're usually morning people. 10pm is the perfect time to go to sleep. Because the first part of sleep is the most restorative part. And I can get into that if you'd like. And so, you know, so So that's great. And then and then you're early morning person. So you wake up, you know, with the roosters, and you're up and you're active, and you're probably full of energy for the day. And maybe you have to take some breaks during the day. But you're pretty high functioning, as you said, then there's a whole bunch of other people who are kind of within that seven to eight hour period. But then there's other people who really need nine to 10 hours of sleep at night. And they really don't function well without that level. And it seems crazy, right? Because that would be double what you need. And why would we be made the same? If we actually need so you know, what, what's the importance of sleep if one person can be fine on five hours, and another person needs 10 hours? Well, as you said, it's all individual differences. Some your sleep might be more efficient, so that you're getting into that deep restorative sleep, and you're staying there, and you're really getting a lot out of it. And then you're getting out and you've got it right. Other people who sleep longer, may need more time because their body hasn't been as efficient in terms of restoring itself. So that's a, you know, question of like, looking into the EEG and seeing what's the differences between or the ECG to what's happening in the brain and the body in terms of those differences.
Alex Ferrari 8:42
So you said that the first part of sleep is when is the most restorative? Can you go into that a little bit?
Sara Mednick 8:47
So sleep is, you know, there's many different studies about five different stages of sleep. But really, we focus on the difference between slow wave sleep, and REM sleep, rapid eye movement, sleep, and then there's stage two sleep, which is sort of the intermediate period between these and slow wave sleep. If you think about the calendar of the day, if you think about not the calendar, but the time of the day, the second you wake up, you're at your most well rested, and basically then you start to have this ticker that's counting out the minutes you've been awake. And that ticker tells you how much slow wave sleep you need. It's called sleep pressure. And your since the moment you wake up, you're building up your sleep pressure to get back to sleep. Because of that wear and tear of being awake, you need a restorative period of sleep, and that occurs during slow wave sleep. So when you first go to sleep, the majority of your sleep is spent in slow wave sleep and you get this really deep, restorative period, kind of like a mini hibernation state. And once you've satisfied your need for slow wave sleep, then you go into rapid eye movement sleep and that's more early in the morning and rapid eye movements. is really a very different brain state from slow wave sleep, it's very active, you see a lot of improvement in creativity, a lot of improvement in sensory memory, like like your perception can get better your audition, auditory processing can get better. And so you have these two bookends of the first part of sleep, and the second part of sleep.
Alex Ferrari 10:26
So during that rapid eye movement time period, is that where a lot of the dreaming happens, and
Sara Mednick 10:32
Yeah, exactly, yeah, that's when the really I mean, you, you sort of have dreams throughout the night. But the really crazy fanciful dreams occurred during REM,
Alex Ferrari 10:41
And is that the ones that stick with you, because dreams come and go. But the ones that actually stick with you a little bit past, when you wake up, has that dream almost every night, some the more emotional ones connect into goes into long term memory, as opposed to just and that really, dreams have a really special place because they're short term memories, but they're like on a very slippery slope, it just goes really quickly, I have to kind of remind myself, or write it down really quickly, to remember it. But sometimes the emotional ones really, really stick. In regards to your research, what part does dreams have in the restorative process of any,
Sara Mednick 11:22
We don't really know, I mean, everything that you're saying about dreams really locks into the science, where the part of the brain that really helps you with the long term memories is the frontal part of the brain, and also the hippocampus. And the more emotional and the more motivational parts of the brain is the amygdala and other areas. And what you find when your brain is in that dream sleep is that that frontal areas shut down. And you're really in this highly emotional motivational state, but without a lot of ability to lay down these experiences as memories. So that's why when you're in that dream state, you're experiencing these highly charged crazy kinds of connections between different stories in your life. But when you wake up, you can't really remember them, because that memory state is, is turned off. But if you if you start wake up, and you immediately start recording it, repeating it to yourself, then that frontal lobe is already turned on, and you can start to rehearse what your what your dreams were. But you know, as far as really understanding why we dream, we're what that has to do with restoration. It's hard to know, we at this point, we understand that dreams may have something to do with laying down long term memories, because their ways of kind of hypothesis testing. Recent experiences can be integrated with your entire semantic knowledge, your kind of knowledge tree, your new experiences get inserted and played with and sort of how does this relate to my dead grandmother or the way you know, the way I played basketball when I was 12. And so you know, you're integrating all these things in a creative way. But really, it's it's a wide open field, in terms of trying to understand dreams, and you know, throughout history, from very early on every you know, every culture has tried to understand it. And we still don't really have a good handle on it.
Alex Ferrari 13:28
Sometimes with that kind of stuff, you have to start leaning into the into the spiritual texts of the ancient texts, and they have some conversations about it. It's really interesting, because I've talked to many spiritual masters and gurus, and many scientists, neuroscientists on the show. And I've talked to both and I find that science and in spirituality is starting to connect more than they ever have before where a lot of the things that were talked about in the ancient texts, like meditation, is being really backed up now by science, like science is catching up to something that's been talked about for 3000 years. So that's what it's pretty fascinating. I think dreams is definitely it's a very deep ocean that we're still trying to figure out without without question.
Sara Mednick 14:13
I mean, to your point, you know, one of the ways so So my research is one of the ones that really showed that the autonomic nervous system is key to many of the benefits that you see for sleep. And, of course, during sleep, you can really have this big shift between the sympathetic fight or flight and the parasympathetic, rest and digest I call it the rev and the restore system, right that you actually when you're awake, you're revved up, and you're really you know, excited and you've got all the resources ready to you know, run away from a lion or go attack a lion. And then you got that that takes a lot of wear and tear. So then you got to switch over to your restore system, which you have naturally during sleep, but you can access that restore system throughout the day, which is a lot of the point of what I'm talking about in the power the downstate and a lot of that has to do with breath. You know, the best controllers have that switch between your stressed, revved up state and your restorative state is controlling your breathing. And truly, I'm constantly amazed by how little modern science understands about breath. And its connection to consciousness and its connection to well being. And really what we learn from it is from meditation and yoga, and Tai Chi and the restorative practices.
Alex Ferrari 15:34
It's interesting because when you said breath, the first person that popped in my head is Wim Hof, which I'm not sure if you've heard of Wim Hof and what he, I mean, what he's been doing with the power of breath, I'll tell you, I tried it. I take cold showers. And it's pretty remarkable the power of breath and and again, talking to some spiritual essence, Tibetan monks and stuff in regards to breath meditations that they use. It is they mentioned that it was so beautiful, the way he presented it, to me is like, what you can live without food, you can live for a while you can live without water for even a little bit. But you can't live more than a few minutes without breath. So breath is life. So when you take deep breaths, you're bringing in more life into you. And it was like, it's just it's obviously so basic and simple. But yet it is a restorative practice. And if you start looking into the yogic practices of breath, and breath control, I know you mentioned panicky breath, when you like, like that kind of breath, your your systems are starting to you're in fight or flight, the slow, deep breaths slows everything down. Is that correct?
Sara Mednick 16:45
Yeah, I mean, you know, one of the one of the real big influencers for me as well was James nesters book breath. And that came out when I was writing my book, and I actually got him to read my book, and he wrote the blurb on the front cover. Because, you know, part, you know, such a key component of creating that balance between your stressed out state and your restorative state is through the breath and is harnessing that. So I think it's, it's, you know, and I will say it again, like, it's amazing how it's very hard to find science around this, except from India, and Tibet, and, you know, places where they've been studying this stuff for years. And, and the stories that come out of those cultures, scientifically, you know, validated are that there's a level of physical control of our bodies, that we have no idea how this has, you know, like, we just can't believe it. But you hear these stories of these Tibetan monks who are, you know, living up in these mountains and, and they have just stone or, or earth floor, and they have tin walls. And they have these competitions, where they put the cold frozen cold towels around these monks and they dry them. They have a competition of how many? How many wet towels, can you dry off your back? Through breathing exercises? Wow. I call it the iron monk. Marathon, like no breathing tests, like, it's just incredible, you know, think of thinking about, Oh, I'm cold, I put sweaters on or I'm hot. Like I'm you know, and you just think you can't you think you can't modulate this stuff. But you can. It just takes a lot of time and effort. You know,
Alex Ferrari 18:38
I mean, I mean, I tested the Wim Hof Method. It's very simple, but it's not easy, simple, but not easy. And you know, and I would go under really ice cold water during the winter, in the shower, and I do the technique, and for whatever reason, I wouldn't warm up. And it was fascinating to me. I was like, wow, um, I mean, I could still feel the cold. But it's my I'm okay with it. It's really, it's fascinating. It just goes against. And if you want to talk about messing with your nervous system, go under some cold, cold water for more than a few for a 234 or five minutes. It messes with your entire everything. It's it's really a fascinating idea. Now in regards to sleep. What does fatigue do to the brain? Because for my understanding, no one can die from lack of sleep to my understanding. I mean, please correct me if I'm wrong.
Sara Mednick 19:36
No, there are no there's there are definitely cases of death from lack of sleep because your internal organs and your subsystems all give up. So it's not like you know, you're not getting sleep doesn't have a knife, it's stabbing you it's that without the restorative part of sleep, your heart gives out your you know, your guts start to decay like like, you know that your your mind starts to give out as well. About that I heard, yeah, yeah. So you definitely can get to a place of actually. And there are people who are, you know, that are genetically unable to sleep and they die very young, they have some amounts of sleep enough to get them going. But they, they die in their 20s. Because they just, you know, their systems can't keep up with their stress.
Alex Ferrari 20:23
So, as you were saying earlier, the the, the short sleepers someone like myself, who can sleep five, six hours and function, what is the long term effects of that on someone who's okay with it, as opposed to someone who sleeps seven or eight hours or nine hours asleep? Is it? Is it again, per body? So like, I can sleep five to six hours a day for and live a very happy life? I'm not I'm not asking you to protect my death. But But what does that effect have on the body? Or is it really just based on the person?
Sara Mednick 21:00
So this is, you know, you're really asking questions that are right at the forefront of trying to understand the like, you know, when long sleep or short sleep matter. So what we know is that, in general, people who sleep fewer hours in their 40s and 50s, they you can predict the onset of their dementia, Alzheimer's in their 70s. Right. And so that seems to say on the because because there's a and the mechanism there is that sleep gives you this deep flushing through of the toxins that build up every day, from just being awake. And using your brain, you have these little proteins that sort of are left in the brain through these interactions. And if you don't sleep, those two, those proteins can be left in the brain and they create the tangles and plaques associated with dementia and Alzheimer's. So there's a there's a gradual buildup of them over time. Now, that is not to say that we that we understand that short sleepers, such as yourself, such as yourself, may have really good efficient sleep. And, you know, we haven't taken those people out of this equation, and seeing whether it's actual time asleep, or is it proclivity to be a short sleeper versus a medium sleeper, a long sleeper? And I think that's a really great question. Because, you know, when I, when I talk to people, I definitely get that that fear look,
Alex Ferrari 22:38
It's not gonna die if I only sleep six hours.
Sara Mednick 22:41
Yeah. Especially in people who are like 70 already, you know, and then they're saying, but I've been a short sleeper my whole life, are you telling me, you know that this is bad. And we just don't know, you know, because we're still at the generalization phase of knowing somebody has Alzheimer's and how they slept when they were younger, right. And, you know, maybe there'll be some years ahead, where we'll be able to make some stronger predictions, and put people into categories. At this time, all we really know is that, you know, the shorter you sleep, the more your chances are of different kinds of pathological failures later in life, but it may not be for everyone.
Alex Ferrari 23:23
Right. And there's also that other part of the equation, lifestyle, diet, exercise, there's 1000 other cues to that. It's like I sleep only five hours, but you know, I eat a perfect diet. And I work out all the time. And I, you know, I meditate and there's all these other things that can associate with longevity.
Sara Mednick 23:42
Yeah, and that brings up a really important point, which is, I think that as a culture, I'm happy that we're focusing on sleep now, because it's been completely ignored. For most of, you know, modern history is the well, at least from the 50s on, people have basically tried to ignore that they need sleep. So now people are really saying, oh, you know, and they're getting anxious about it, like, how do I get more sleep, but now we're putting too much pressure on sleep, right? And so and that's really what the book is about is saying, You need to work on your autonomic nervous system, sleep and circadian rhythm as part of that, and exercise and nutrition, exactly, as you said.
Alex Ferrari 24:23
So and that's the other thing too, that I'm a very heavy meditator. So I meditate one to two hours a day, in addition to being a short sleeper. Now, I know from studying many gurus over the years, and even speaking to some very heavy Tibetan monk meditators, they, many of them say I can sleep an hour or two. And as long as I meditate for few hours, I'm good. So they kind of almost get the restorative thing of sleep in the meditation when they go deep into the meditation. What kind of what kind of research have you seen In meditation and how it deals in the restorative process,
Sara Mednick 25:03
What type of meditation do you practice?
Alex Ferrari 25:06
I just, I'm an old I just tools who close my eyes and, and I, the way I personally I don't do TM or any of that, that kind of meditation. I taught myself my own kind of meditation, which is, I was talking to a meditator the other day about a gerund. I remember seeing the movie castaway. With Tom Hanks. Yeah, you remember that movie?
Sara Mednick 25:27
I do remember. Yeah!
Alex Ferrari 25:29
So remember that he couldn't get off the island, because there were waves, the waves just kept crashing, and he had to figure out a way to get past the waves, while the waves or the or the monkey brain, those are the thoughts. So the goal of a meditator is to get past the waves, because once you get past the waves, then it all goes quiet. So I've taught myself a way to do that, myself where doesn't work all the time, but it works most of the time where I can get past the waves or the monkey brain. And it just, I go, and I'm gone. And sometimes, if I go deep enough, I wake up, I mean, better than a night's after an hour, hour and a half, I can wake up feeling better than I did when I woke up in the morning. So super deep, deep meditation where I can I lose track of time, and I go to a place that I really, I don't know where it is, but it's very peaceful place. And it's a very deep place. And that I and I just truly I walk around with it, it's called the kind of like, the high you're in bliss, bliss is the best word I can use for it. So this blissful state, I can get to that place, not all the time. But most of the time I get to that blissful state. And I walk around high for probably about five or 10 minutes, just like literally just high off of whatever, wherever it came from. And I have to like, work my way back out. So I'm a little groggy of getting out of a deep sleep when you feel groggy, same thing with a meditation, but it's almost, it's different in a different way. So that I think helps with my short sleep. And I haven't always done that only been meditating, probably five years, I would say maybe five, six years, deeply. But I just love to hear your research in regards if there's any research in regards to the restorative practice of meditation.
Sara Mednick 27:15
Yeah, so, so people who are super meditators, definitely sleep less your hours. And that is, you know, documented multiple times know that. Yeah, yeah. And the idea is, you know, so So most of neuroscientists focus a lot on what's happening from the neck up. And so part of the contribution from my lab is that we are interested in the neck, up, but also in the neck down. And really, the autonomic nervous system, right, which we've already talked about a little bit, which has these two branches, you know, the revved up fight or flight system, or the restorative Rest Digest. So what you find when you go into this meditative state, is that you're really shutting down that fight or flight system, and you're going into this super expensive restorative system. And that's exactly what happens when you go to sleep. So when you're in that really deep restorative state, your sympathetic revved up system is completely shut down. And in fact, when you have high levels of sympathetic arousal, this leads to poor sleep, at least a waking up and it leads is correlated with, you know, having a bad day, the next day, but also with cardiovascular disease, you know, long term hypertension, right? Because you need that deeply restorative state for your, your heart, for your guts, for your metabolism for your brain, to go into this kind of hibernation state. And what that really is, is going into this deeply restorative, parasympathetic, rest and digest system. So when you're meditating, you're actually taking care of the business that would naturally be occurring during sleep.
Alex Ferrari 29:03
So it's kind of like so then so let's talk about the power of the nap. Because the NAP is extremely powerful. I've I was listening to an ex Navy SEAL. His name's Jocko, who's very famous goes around, he's like, I sleep four hours a day. He goes, but I'll take an hour nap. He goes, I put my feet up above my, above my heart. And he goes and you and you take 30 minutes and he goes, you'll wake up more restored than you if you'd slept eight hours. He said that like he's amazing, but he's like a really. He's, you know, he's a pretty interesting fellow to say. He's amazing. But yeah, so what are the what is the power of the nap? And is is this is why children. Newborns sleep so much.
Sara Mednick 29:50
Yeah, you know? Absolutely. And why a lot of humans actually adult humans need to nap as well. So it looks like about 50% of the population are nappers and the other population really are not nappers. And, you know, I came out with my book in December 2006. And by then I had done a bunch of research on napping showing that you can get the same benefits from, from a nap that's like an hour to an hour and a half in the middle of the day, as you can prove a full night of sleep. And we showed this multiple times with multiple different memory tests. And it was sort of shocking. But then I kept hearing from people saying, but I feel so horrible when I wake up from a nap and I hate napping, and how do I learn how to nap I want to get these benefits. So even though I was sure all everybody can nap, they just need to try. Then I did research trying to train you know, looking at nap non knappers versus knappers. And I found out in fact, non nappers don't get a lot of benefits from a nap. And when I tried to train non nappers to nap on a regular basis, and then tested them across a month, I still couldn't get them to get any benefits out of the nap. So the NAP is wonderful. But it's really not for everyone. And probably in that same way that we have genetic variability in our sleep need at night, we also have the same genetic variability in our sleep we need during the day. So some people really need to nap because it's exactly what their body needs. But other people need to go out for a walk in the woods, or exercise or meditate, right that you actually are getting the same benefits to your body and your brain. But you need to do it in the way that works for you.
Alex Ferrari 31:40
So I have to ask this question, because I remember, and I've had this conversation with friends of mine. I know you remember when you were a teenager, and you could sleep 12 hours, 13 hours, just sleep like a log, I couldn't sleep 12 hours if I tried, it's just something that my body can't do now. Why is it when we're younger, we sleep, we can have the potential to sleep lots more. And as we get older, we lose that ability as we you know, because I know, I remember my grandfather would sleep for hours wake up, and like, you know, he's wake up. And that's why you had dinner at four. boundary is a completely different cycle. So why is that? Why? Why does it why human beings do that.
Sara Mednick 32:27
So when we're younger, we are experiencing a huge amount of growth. And you know, one of the most important aspects of sleep is that it helps your brain and body grow and learn. So that's really, you know, can can help explain why from infants to you know, 20 years old, we're still really able to tap into that sleep as that growth potential. The reason why we can get really consolidated long periods of sleep, when we're that age as well is that we have very strong circadian rhythms that shut us down, you know, that help us be really awake during the day high arousal, and then when it's time for sleeping give us very strong cues strong onsets of melatonin, to help us stay asleep throughout the night. As we get older, we start to have weaker circadian rhythm signals, maybe it's that our eyes aren't getting the right color of light into our brains as well maybe because we're seeing too many screens but also just because, you know, the failure of our of our visual system across age makes it so we're not getting as much blue light to really wake us up and to really keep us you know, asleep. But we also just produce less melatonin. And that means that we don't get these long periods of sleep. We have many more circadian arousals while we should be having circadian rest. So that's, you know, one of the things that's really important as you get older, is to you know, become aware of how your age is impacting your ability to get downstate sleep, and just to get downstate anything whenever you want it so you need to like really kill yourself in the morning. This is morning, I'm starting the Upstate I want my arousal to be high. Get the right light in your eyes. You know, that means sun or a bright light box. A great way to jumpstart your Upstate is through exercise in the morning, getting yourself you know jazzed up through your rubbing up your sympathetic arousal system. Eating is a great way to entrain the circadian rhythm. So eating is a creates a stress response in your body. So eating during the day when you want the upstate to be up is is really a great cue and then stopping eating At a certain period of time to tell your metabolism that you're going to go into the downstate. So a lot of the reason why, you know, we're being told to have this time restricted eating and really, you know, fast for long periods every day and every night is because your tap your metabolic system needs a downstate as well. And that allows it to regenerate and be as strong as it needs to be for that upstate intake of energy.
Alex Ferrari 35:27
So the magic question is, When should we stop eating?
Sara Mednick 35:33
It depends on what is feasible, I think for people, you know, I think it's so important to think about, are you somebody who really has a structure that you can just, you know, keep the same structure every day. And for that, I would recommend time restricted eating where you just, you know, you start in the morning, and then you stop at, say 786 PM, like whatever you can in that domain. And then just give yourself a nice big fat downstate every night. But then there's people who travel, and who need to, you know, go out for to work dinners, and who need to, you know, do all sorts of things that make it that that kind of a schedule is actually really hard to maintain. So for that, I think it's great to just take a day, every few days or once a week, and eat a very small amount, because you're also in that. In that same vein, giving yourself a nice, big downstate for your metabolic system for a whole day.
Alex Ferrari 36:32
So how many hours give or take before sleep? Should we have nothing in our system?
Sara Mednick 36:39
I mean, it's recommended to have about three or four.
Alex Ferrari 36:42
That's rough. Yeah.
Sara Mednick 36:45
If you think about it, here's, here's here's what's going to, you know, I think an important thing to think about. So insulin, right, that is generated, stress Gen generating early in the morning, this is the the nutrient that helps get change your food into usable energy, right, and it shuttles the nutrients into the cells. So that's really important, because then if that insulin is high, then your metabolism is super efficient, and you're using all the food and you're turning it into energy sent sending it right into the cells. So as you go across your day, insulin starts to decay. And your ability to make insulin gets worse and worse and worse. So by the end of the day, when you're eating, not a lot of that food is actually being shuttled into the cells, it's just being stored as fat. So your, your whole metabolic system is going into a down state. But if you keep eating, your food is not going to be used efficiently, it's going to be stored as fat if you eat at night. And usually when we eat at night, our frontal lobe is shut down. We're not making our best decisions. We eat, you know, high sugar, high fat foods as well.
Alex Ferrari 38:04
So the midnight snack is not something we should be doing,
Sara Mednick 38:07
For several reasons.
Alex Ferrari 38:10
Several reasons. Now, what is lack of sleep or fatigue due to the brain, actually the chemistry of the brain and how it functions.
Sara Mednick 38:20
So, lack of sleep. Lack of sleep basically does all the you know, it basically keeps the things that sleep does at bay. So sleep is helping you with consolidating your memories. It's helping you with emotional regulation. It's helping you clean out the toxins in your brain, it's helping you repair muscle tissue. It's helping you create new proteins in your body in your brain, build up backup, your glycogen stores, all those things are really important. And give your heart a break. Right that brings your heart rate down really significantly. So when you have chronic levels of sleep deprivation, and you're chronically sleep deprived, you're in a chronically stressed state basically chronic sleep deprivation is the same as chronic stress. And what that what does that lead to? Well, it leads to hypertension and heart disease. It leads to obesity, diabetes, it leads to all the main players poor gut health you know later it can lead to cognitive dysfunction. So, you know, it's definitely something that we want to you know, focus on but also not make ourselves anxious about
Alex Ferrari 39:39
Stressing about stressing. We are such interesting creatures, aren't we?
Sara Mednick 39:47
It's a delicate balance there.
Alex Ferrari 39:50
No, I heard you talk about the vagus is that the vagus nerve?
Sara Mednick 39:55
What is that? Okay, great. So the vagus nerve is basically the radial nerve that comes from the body, and it's attached to all your major physical organs. And it sends information to your brain. So it's basically the free way for all of your body information to be sent up to the brain.
Alex Ferrari 40:15
Is it like, Is it like the brainstem, if you will, is it in there are
Sara Mednick 40:19
A part of the brain where the vagus nerve connects to the rest of your brain? Yeah. And so what's important about that is it's telling you a lot of information about how stressed you are, you know how your guts you know, when you're getting nervous about something in your gut start to run, you gotta run to the bathroom, if you're really, really nervous, right, or if you see somebody, you get butterflies, that's the vagus nerve connecting your body to your brain, right and telling your guts like, Oh, I'm excited, or I'm scared. So there's a strong connection there between your guts and your brain through the vagus nerve. But it's also a strong connection to from your heart, to your brain. So when you get excited, your heart starts to race. That's because of the vagus nerve. So the vagus nerve is controlling the is basically representing or reflecting your parasympathetic, rest and digest system. So when the vagus nerve is turned off, that's when you get super excited, right? And you're kind of really, you know, sending a lot of excitatory information, when you start to engage deep breathing and calm down, and you're able to self regulate, that's the vagus nerve turning on and saying, Okay, let me you know, take a break and deep breathe deep breathe, and, you know, make sure I've got a hold of myself.
Alex Ferrari 41:38
So this isn't, this isn't a neuroscience geeky question. So please bear with me. It's a little slightly off topic them but might be not off topic, depending on your answer. I was told that there's kind of a barrier between the brain and the rest of the body, which is that not allowed toxins to get through that that barrier. Very few things can get through it. Heroin can get through it, cocaine can get through it. I was told mushrooms, certain mushrooms for the health benefits can get through it. Is that a true? Is that a true statement?
Sara Mednick 42:13
Absolutely. Yeah. And so there's lots of you know, medications are really important in that ways. Can they cross this thing called the blood brain barrier? Some medications. You know, there's if you think about antihistamines, that's a perfect example of when people have allergies. Some of the medications make them drowsy, right, but the Claritin ones are ones that the and the reason why they make them drowsy is because they cross the blood brain barrier, and they get into the brain. So now what they're trying to do is calm down your histamine reactions in your body. But they're also making you drowsy, right? But the Claritin versions don't cross the blood brain barrier. So it just affects your body, but it doesn't affect your brain.
Alex Ferrari 42:56
So that's why if not, I mean, every time you eat McDonald's, or some bad food or something like that, or maybe some chemicals or toxins could affect the brain and that that blood brain barrier is there to protect the brain from toxins or poisons or anything like that, that might get into our system. Correct?
Sara Mednick 43:13
Exactly. And, you know, one of the ways that things like that can get into your brain is through your guts B is through the vagus nerve. Because the gut brain connection, the if you have any sort of you know, poisonous or bacteria that's in the guts, and you have leaky guts, this is a leaky gut syndrome. That means that those bacteria can travel up the vagus nerve and into your brain. And there's associations between mental illness and poor gut function due to this highway.
Alex Ferrari 43:48
So it's kind of a backdoor, if you will. Yeah. It's like a backdoor into the brain. Because I've had multiple guests, I'm talking about the gut, I've, I've been preaching about the gut for a while now. Having a good microbiome and how it helps your body and helps you helps your brain function helps everything immune system, the whole thing. I've become fairly obsessed with the microbiome, which is a good thing I've just been trying, I've been trying to take care of it. But that's something that a lot of people just don't understand that gut is very beneficial. It actually is everything.
Sara Mednick 44:19
Yeah, I talk about a lot in my book. And I actually, you know, I sort of, you know, the fact is that it's its own entity. It's like a huge apartment complex, filled with a lot of different bacteria. And they all live and they're completely separate from you. And the question is, is it like, you know, in the hood and like a really, you know, mix mix of sort of good and bad, or is it you know, more on the bad side? Or is it you know, we're getting into some sort of, you know, good neighborhood was like, everybody's taken care. Everyone cares about, you know, taking care of the neighborhood, right. So, that's, you want to
Alex Ferrari 44:59
Has an HOA. always has an HOA Yeah, yeah, dinosaurs on the on the lawns, right?
Sara Mednick 45:05
We are taking no cars on the lawn. Right, right, we are taking care of our neighborhood. And it's not. It's not necessarily you, right? Because these are independent bacteria that are helping you digest your foods, right? There's many foods that our bodies don't actually naturally digest, but the guts do digest, so you want to keep those guys happy. And then you want to try to keep them from letting the bad guys in.
Alex Ferrari 45:33
Right! And that's why there's things like prebiotics and post biotics and and probiotics and all that kind of stuff to help you with that. Like, just straight up spinach salad.
Sara Mednick 45:43
Yeah, you have to eat a lot of those probiotics and, and supplements in order to actually have an effect and you have to do it regularly and be really diligent about it. So I think also just eat well don't eat at McDonald's, you know, like, you know, keep all those good foods in your in your diet every day.
Alex Ferrari 46:04
I was talking to a doctor the other day about it. And he's he said, there's like, I mean, you supplements like yeah, if you want to use a couple here and there if you want but just eat a salad man and you're gonna get a a much wider variety of probiotics and and food for the bacteria, which is really interesting. It's kind of really an interesting idea that microbiome, which is that I feel that it's a lot of people are talking about it now, where before they really weren't five years ago, I didn't hear a word about microbiomes or the importance of them.
Sara Mednick 46:36
I mean, there was always the poop transplant, which you can't.
Alex Ferrari 46:40
Oh, there's that. I heard about that, too. Yeah. And there's some there's been some really amazing science behind that there. People are like, deathly ill, and they literally jam poop back up into the healthy poop with a really good bacteria.
Sara Mednick 46:57
There's a paper that talks about repopulating the gut, it is a great it's a scientific article that has it's just so you know, it's such an amazing idea that it's not just for gut health, but you know, this is going to be a treatment for mental health as well for depression, anxiety, and potentially also schizophrenia. You know that this connection is actually really important.
Alex Ferrari 47:20
I love the scientists are becoming stand up comics with the poop repopulating? No, but this is, this is all connected because at the end of the day, we're trying to think about the brain and think about just our restore just our body isn't a machine and in the downstate, and sleeping and restorative processes is part of this really giant ecosystem of what what we run? I mean, it is, this machine is fairly amazing. The design of us is quite remarkable. I have to say, as I get older, I realized that by the way,
Sara Mednick 47:59
And it's a huge point to think about, like I have, I have, I've been writing on medium. And I have this essay called I'm anti biohacking. And it's really saying, the idea that you can bio hack, right, like hack, any kind of word hack shouldn't be part of your body like, right hacking is that you can try to trick a system that you can do a short, quick and dirty approach to health, you don't need to the system has been going for millions of years, right of billions of years in terms of just general, you know, circadian rhythm development across bacteria. So we can actually just rest in this idea of this whole nature system has been doing this a lot longer than us. And if we get into this bio rhythm idea of fitting in our activities, when we're optimized to be active and fitting in our downstate activities, when we're optimized for rest, you'll see so much benefits later on in you know, day to day, but also later on, right that, that all that chronic disease and chronic problems that we're seeing those will go away. If we tap into these bio rhythms,
Alex Ferrari 49:08
Which again, can you've said circuit, circadian, circadian, I can't say a word Kadian circadian rhythms a couple of times in this conversation. Can you explain to the audience what that exactly is?
Sara Mednick 49:19
Yeah. So the circadian rhythm are basically like every cell in your body has a little clock in it. And it tells you know, that cell has an upstate and downstate is basically just a rhythm. Circadian rhythm specifically is the 24 hour rhythm. And it's guided by light mostly, and it's guided by the sun. The fact that we've had the Sun and the Earth spins on an axis gives us a half a day of light and half a day of darkness. Right? I'm not sure in Alaska. Yes. Well, though, that's very interesting because people who have been genetically for many, many years and animals that have stayed up in those winter areas, they have a different circadian rhythm and they're able to actually ignore the light signals and keep their internal circadian rhythms despite the light not changing by the light being or darker light, but they still have circadian rhythms. They're just in there what's called endogenously driven meaning that their body tells them what's going on and you get it from you know, you can also drive your circadian rhythm by first is light, that's the biggest time giver. Basically, it's called Zookeeper, but also eating that's why you know, time restricted eating is so popular is because it's really setting up your circadian rhythm. Now is the beginning of my day now is the beginning of upstate I'm eating now I'm stopping eating now is the beginning of my downstate, right, exercise massive for timing, the UPS states and the down states. Any kind of habits that you keep that actually will tell you what time it is, why do you why does your stomach grumble? You know, say 20 minutes or so 15 minutes or so before you regularly eat lunch? It's not that there's a you know, golden hour for eating lunch that all of our stomachs growling. It's just that that's usually when we get lunch, right? So then our systems have learned by habit to create a rhythm around that eating period. And it's getting your body ready for intake of sugars and fats and proteins. And so you really are sort of pre gaming.
Alex Ferrari 51:32
So then if so if if we do eventually populate Mars or another planet with a different circadian rhythm, I don't know what the day is the Mars Martian day is I don't think it's a 24 hour day. But our bodies will, the astronauts whoever are there would eventually create their own rhythm based around where they are. That's, that's the, the genius of our system. Is that fair?
Sara Mednick 51:58
Yes, it takes a long time to adapt. So I think that it won't be like a quick, easy thing. But basically, yes, that's the idea is that over time, you know, either through artificial light sources, or through just the natural light of Mars, that your system would adapt to that rhythm.
Alex Ferrari 52:17
So let's say that you, you, you're having problems, get into bed. What are a few not hacks, because that's a bad word. But tips we can do to get ourselves properly in our sleep, because I know, like, I have a bad habit. I watch television all the way up until I go to sleep. And I just turn the TV off and I go to bed. I know that's not ideal. So what is an ideal routine? Before you go to bed? And then what are hacks to make us fall asleep? If we can?
Sara Mednick 52:48
Yeah. So I mean, as I, you know, I'm really interested in how we not just, you know, the hour before we go to sleep, but what about like the whole 12 hours of the day, 15 hours that we've been awake, what are we doing there, so I start there. And make sure that a lot of the morning time is when you do your intense cardiovascular exercises, is when you do the majority of your eating like say, you know, before three o'clock, you should have at least 50% If not more of your take. So pushing your, the more intensive or stressful experiences to earlier in the day. And then engaging in slow deep breathing, right, like, you know, the the issue is, is that if you just continue to raise your stress levels across the day, without taking dips into the downstate, right, that just kind of level you off and level you off, you get to the state of actually pretty high stress, by the time you're heading to bed. And that sleep, it hurts, it's hard to sleep, it puts a lot of pressure on your brain to try to turn off when your mind is running when you've gotten you know, so much activation throughout the whole day. So taking, you know, a lot of time. Not a lot. But let's say 10 minutes across the day. I know you do a lot more.
Alex Ferrari 54:11
Yeah. But that's I'm understanding now just by you talking how important these little meditative state states that I do are in my lab, I had no idea.
Sara Mednick 54:21
They're massive. Yeah. Because they keep you at a much more regulated, self regulated level so that by the time even if you're going to watch a movie before bed, you're not entering that state already so ramped up, and then watching a movie that's also scary or whatever, you know, that's sending a lot of light into your eyes like or, you know, God forbid, right? It's the social media time, right? It's fine. Right? And then you get on the news and then you start reading about like the environment and like the drought in China that I just was like exposed to in the middle of the night last night like okay, I'm gonna sleep right you know, Like, it's there's a lot of scary stuff happening right now. And so if you expose yourself to that when you're already trying to get to bed, that's not you know, so So as much as you could do to put yourself in that deeply relaxed state, and keep yourself, you know, dipping into it throughout the day, but then at night, keep the blue light down, right? There's I do, I haven't yet yeah, blue blockers, like blockers that are really, really cool. And you make the lips.
Alex Ferrari 55:26
They're very slick, I have to say,
Sara Mednick 55:29
But don't wear them during the day, because that would be the wrong signal to your brain. So I really like these blue light blockers. I wear them at night now.
Alex Ferrari 55:37
So what So what you watch? Do you watch television with them on?
Sara Mednick 55:40
Oh, I'll watch television, I will do read my book, everything. Everything that I do, I'll keep those those glasses on. Anytime after say seven o'clock, I'll start wearing them. Interesting. So it's super relaxing, I find that when I put them on, I'm suddenly because there's a lot of stress that you get from the information coming into your
Alex Ferrari 56:00
Especially if you're on monitors all day. Yeah. So I just I just as you were talking, I was remembering the day that I went to eat all you can eat sushi at 11 o'clock at night. Let's say I wasn't a good night's sleep at all. Because you're young. I was not wasn't that young. I was my early 40s. And that was stupid. That was just straight up stupid. So among other problems that that all you can eat sushi, at 10 or 11 does. It doesn't it was a very difficult sleep, and then you're you're digesting and it was just so much food, because you gotta get your money's worth. So it was it was a really difficult night to, to deal with. And then I remember sometimes we watch let's say we watch a thriller, a war thriller or you know, an espionage show like a James Bond or, or just something violent, super violent before you go to bed. Like I remember we watch a show we didn't know is gonna go in that direction. And it went in that direction. And then my wife is like, I can't I can't get asleep. And the next morning, she was like, I just was dreaming about assassinations and this or that. Exactly. It's it's uh, we're really cautious now of what we watch. Right before bed. Yeah, you know, weekends are different. But like on the weekdays, nothing too super heavy, or if not at least an hour
Sara Mednick 57:25
And cost, right. Like you think about like, how am I going to be the next day, I've got all this stuff to do. I've got kids, I gotta be up in the morning and like, get them to school, and I've got to be in a good mood. And then I've got to have them when they get home and like have energy for them. Like, it's not worth it, you know, but but the problem is, is that in those moments at 11 o'clock, right, is when our frontal cortex is shut off. So it's actually quite difficult to make that decision to turn off Netflix, or to say no to that scoop of ice cream or to not respond to some horrible rent from you know, an uncle that you just can't stand it so that's, that's really the problem is and so I think it's really important when you think about like, how do I deal with that is setting up habits. And in the book actually one of the I have a plan that's a it's called the downstate recovery Plus plan and what it is basically just gives you a system for how you can add one habit a week. And so you have your your down state plan running on all four cylinders, right, where you're, you have things that keep you at a habit level. So when the time comes, you don't have to make that decision anymore. You already have this, this is what I do. You know, I stop eating at this time or stop watching TV at this time. Or, you know, I this I'm getting my exercise in at this hour or whatever it is, you know, there's a long list of all the different options.
Alex Ferrari 58:50
Yeah, and obviously, when you start exercising you sleep deeper. I found especially when you start time you exercise though, right? So some people are late, late exercisers, they will do it like after work. I'm an early morning five o'clock in the morning kind of exerciser and I do heavy all my heavy stuff there though I do sometimes do a double and I'll go to the gym around for but still plenty of time prior
Sara Mednick 59:15
4 is alright. I mean I I think I do get worried about people who are stretching it into like
Alex Ferrari 59:21
7 8 9.
Sara Mednick 59:25
Yeah, yeah. Really. I mean, you can do weightlifting, a little bit. But if you're really running your cardiovascular system, that's going to it's going to increase your body temperature. It's going to increase your heart rate and that stuff takes a long time to calm down. So people who I know who are nighttime exercisers, they often don't sleep very well.
Alex Ferrari 59:45
Right exactly because of that. It's but I found it that early morning routine of just waking up going working out. It just gets the ball rolling for the day. It just starts the engine running starts everything going. You eat or It just it just sets everything up properly. I feel so much and I slept. Both my wife and I have been doing a lot more working out lately and we start to feel we start going to bed at like, Oh, it's 930 Should we go to bed? It's it's way too early. I'm like, Let's go to bed.
Sara Mednick 1:00:16
Yeah, that thought of like, I feel lame.
Alex Ferrari 1:00:19
I feel like Am I a loser? Do we just go to bed at the same time I chose our little girls went to bed. But we were exhausted and because of our bodies working out especially when you starting a routine that you're not used to you but but you sleep so much better. And exercise just burns out so many different things in your body. In your mind. It's It relieves stress, it does so much good for you. Even minor exercise.
Sara Mednick 1:00:47
Yeah, increases mood. I mean, it really is an elixir.
Alex Ferrari 1:00:51
It is without question. And now where can people find out more about you your book and the work that you're doing?
Sara Mednick 1:00:57
I have a website. My name is Saramednick.com. And my book is available anywhere. I mean, Amazon, obviously bookshop, any website but also bookstores, ask for it in bookstores, if you don't find it, it's always great for authors to have their books requested. And then my contact information is on my website. And I have a give talks and all sorts of and workshops and you know, always happy to talk to people about their ideas for different events.
Alex Ferrari 1:01:29
Sara it's been a pleasure talking to you. Thank you so much for enlightening us on the power of sleep and naps and the downstate and everything we've talked about. I've learned a lot about this, and hopefully everybody listening has as well. So I appreciate you and the work that you've been doing to help people so thank you so much.
Sara Mednick 1:01:44
It's my pleasure, Alex, thanks so much for having me on.
Links and Resources
- Sara C. Mednick – Official Site
- Listen to Audible – The Power of the Downstate
- The Power of the Downstate: Recharge Your Life Using Your Body’s Own Restorative Systems
- Earthing.com: End Inflammation Today – Discover the Science-Based Healing Powers of Earthing/Grounding
- FREE Mindvalley Spiritual Masterclasses
- MUSE 2: The Brain Sensing Headband – Meditation Tracker Headset Device
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