Essentials: Sleep Toolkit for Optimizing Sleep & Sleep-Wake Timing

Channel: Andrew Huberman / Huberman Lab URL: https://www.youtube.com/watch?v=RTgJSQtvo88

Transcript

[00:00] Welcome to Hubberman Lab Essentials, [00:01] [music] where we revisit past episodes [00:04] for the most potent and actionable [00:06] science-based tools for mental health, [00:08] physical health, and performance. [00:11] I’m Andrew Huberman, and I’m a professor [00:13] of neurobiology and opthalmology at [00:16] Stanford School of Medicine. Today, [00:18] we’re talking all about sleep and how to [00:20] optimize your sleep. Let’s consider what [00:22] the perfect 24-hour cycle would look [00:26] like. Regardless of when you wake up in [00:28] the morning, one of the first things [00:30] that happens is that your body [00:31] temperature is increasing. And that’s [00:33] just going to happen naturally. That [00:35] increase in body temperature in turn [00:38] causes an increase in the release of a [00:40] hormone called cortisol. Cortisol is [00:42] often con demonized and considered this [00:44] bad thing. And indeed, you don’t want [00:46] cortisol to be chronically or [00:48] consistently elevated throughout the day [00:49] or night. But you do want cortisol to [00:52] reach its peak early in the day, right [00:54] about the time you wake up. One way that [00:57] you can ensure that that cortisol peak [00:59] occurs early in the day, right about the [01:01] time that you wake up, is to view bright [01:04] light, ideally from sunlight, within the [01:06] first 30 to 60 minutes after waking. The [01:09] reason for that is very simple. You want [01:12] to trigger that cortisol increase to [01:14] occur very early in your day, and you [01:17] don’t want that cortisol peak to happen [01:19] later, which is what will happen if you [01:21] wait to get outside and see sunlight. [01:23] The reason for this is that you have a [01:26] set of neurons, nerve cells in your eye. [01:28] They’re called intrinsically [01:29] photosensitive melanopsin cells, but you [01:31] do not need to know that name. Those [01:32] neurons respond best to bright light and [01:35] especially right after waking early in [01:37] the day. They are best able to signal to [01:40] a set of neurons that reside over the [01:42] roof of your mouth called the super kisa [01:44] nucleus which is a cluster of neurons [01:46] that then sends a huge number of other [01:48] signals electrical and chemical out to [01:50] your entire body that triggers that [01:52] cortisol increase provides a wakeup [01:54] signal for your brain and body and sets [01:56] in motion a timer for you to fall asleep [01:58] later that night. Here’s what you do, or [02:00] at least here’s what I do. I wake up in [02:01] the morning and I want to reach for my [02:03] phone. But I know that even if I were to [02:06] crank up the brightness on that phone [02:07] screen, it’s not bright enough to [02:09] trigger that cortisol spike and for me [02:12] to be at my most alert and focused [02:15] throughout the day and to optimize my [02:16] sleep at night. So, what I do is I get [02:18] out of bed and I go outside and if it’s [02:22] a bright clear day and the sun is low in [02:25] the sky or the sun is, you know, [02:27] starting to get overhead, what we call [02:28] low solar angle, then I know I’m getting [02:31] outside at the right time. Especially on [02:33] cloudy days, you want to get outside and [02:35] get as much light energy or photons in [02:37] your eyes. But let’s say it’s a very [02:39] clear day and I can see where the sun [02:41] is. I do not need to stare directly into [02:44] the sun. So, the way to get this [02:46] sunlight viewing early in the day is to [02:49] look toward the sun. Never look at any [02:52] light, sunlight or otherwise, that’s so [02:54] bright that it’s painful to look at [02:55] because you can damage your eyes. But [02:57] for this morning sunlight viewing, it’s [03:00] best to not wear sunglasses. That’s [03:02] right, to not wear sunglasses. It is [03:04] absolutely fine to wear eyelasses or [03:07] contact lenses, so-called corrective [03:09] lenses. In fact, those will serve you [03:11] well in this practice or this tool [03:13] because they will focus the light onto [03:14] your neural retina and onto those [03:16] melanopsin intrinsically photosensitive [03:17] ganglen cells. This is grounded in the [03:20] core of our physiology. There are [03:22] literally hundreds if not thousands of [03:23] quality peer-reviewed papers showing [03:25] that light viewing early in the day is [03:28] the most powerful stimulus for [03:29] wakefulness throughout the day and it [03:32] has a powerful positive impact on your [03:34] ability to fall and stay asleep at [03:35] night. So, this is really the [03:37] foundational power tool for ensuring a [03:40] great night’s sleep and for feeling more [03:42] awake during the day. If you wake up [03:44] before the sun is out, you can and [03:47] probably should flip on artificial [03:49] lights in your internal home environment [03:51] or apartment or wherever you happen to [03:53] live. If your goal is to be awake, [03:55] right? If you wake up at 4 in the [03:56] morning and you need to be awake, well, [03:57] then turn on artificial lights. If [03:59] you’re asking whether or not turning on [04:00] artificial lights can replace sunlight [04:02] at those hours. Unfortunately, the [04:04] answer is no. Unless you have a very [04:07] special light, we’ll talk about what [04:09] kind of light. The bright artificial [04:11] lights in your home environment are not, [04:14] I repeat, are not going to be [04:15] sufficiently bright to turn on the [04:19] cortisol mechanism and the other wake up [04:21] mechanisms that you need early in the [04:23] day. The diabolical twist, however, is [04:25] that those lights in your home or [04:26] apartment or even on your phone are [04:29] bright enough to disrupt your sleep if [04:32] you look at them too late at night or in [04:34] the middle of the night. So, there’s [04:35] this asymmetry in our retinal, our eye [04:38] biology, and in our brains biology [04:40] whereby early in the day, right around [04:42] waking, you need a lot of light, a lot [04:44] of photons, a lot of light energy. And [04:46] artificial lights generally just won’t [04:48] accomplish what you need them to [04:50] accomplish. But at night, even a little [04:53] bit of artificial light can really mess [04:55] up your so-called circadian, your [04:57] 24-hour clocks and all these mechanisms [04:59] that we’re talking about. On cloudy [05:00] days, you especially need to get [05:02] outside. I repeat, on cloudy days, [05:05] overcast days, you especially need to [05:06] get outside and get sunlight. You just [05:08] need to get more of it. Now, how much [05:10] light and how much light viewing do you [05:12] need? This is going to vary depending on [05:14] person and place. I mean, literally [05:16] where you live on Earth, whether or not [05:17] there’s a lot of tree cover, whether or [05:19] not you’re somebody who has sensitive [05:21] eyes or less sensitive eyes, it’s really [05:23] impossible for me to give an absolute [05:25] prescriptive, but we can give some [05:26] general guidelines. In general, on a [05:28] clear day, meaning no cloud cover or [05:30] minimal cloud cover, you want to get [05:32] this sunlight exposure to your eyes for [05:36] about five minutes or so. Could be 3 [05:39] minutes one day, could be 7 minutes the [05:40] next day. about 5 minutes. On a day [05:44] where there’s cloud cover, so the sun is [05:46] just peeking through the clouds or it’s [05:47] more dense cloud cover, you want to get [05:50] about 10 minutes of sunlight exposure to [05:53] your eyes early in the day. And on days [05:55] that are really densely overcast or [05:57] maybe even a rainy, you’re going to want [05:59] to get as much as 20 or 30 minutes of [06:02] sunlight exposure. Just don’t try and [06:04] get this sunlight exposure through a [06:06] windshield of a car or a window, whether [06:09] or not it’s tinted or otherwise. it [06:10] takes far too long. It’s simply not [06:13] going to trigger the relevant [06:14] mechanisms. Now, if you live in a part [06:16] of the world where it’s extremely dark [06:18] and overcast or the weather won’t let [06:19] you outside or you live in a cave, there [06:22] are sunlight simulators or daylight [06:24] simulators that you can purchase. Those [06:26] are quite expensive in general. [06:28] Therefore, I suggest cheaper options [06:31] that work just as well because they get [06:33] just as bright. things like ring lights [06:35] that are sold in order for people to [06:37] take selfies and this kind of thing. A [06:40] LED tablet will work pretty well. I [06:42] actually have one of those and I put it [06:43] on my desk all morning even though I [06:45] still get outside and look at sunlight [06:47] first thing in the morning. Again, also [06:50] especially I should say on cloudy days. [06:52] Many of our listeners live in locations [06:53] throughout the world where for instance [06:54] during the winter it gets very very [06:56] dark. So they can’t get sufficient [06:57] sunlight. But get that morning light, [07:00] ideally from sunlight, and take into [07:02] account all the specific points that [07:04] I’ve given you here. When you start [07:06] doing this, you’ll notice that your body [07:09] will start to feel more energized and it [07:11] will feel more energized more quickly. [07:14] You’ll actually start to notice this [07:16] mechanism kicking in each day, [07:17] especially if you’re paying attention to [07:18] your physiology. It’s that diffuse, very [07:20] bright sunlight, that photon energy that [07:22] you really want. That’s going to set all [07:24] the rhythms of your brain and body in [07:25] the proper way. Not just that cortisol [07:28] peak, but it’s going to trigger proper [07:30] metabolism. It’s going to set a timer [07:32] for you to be able to fall asleep about [07:34] 16 hours later. It’s also going to [07:35] suppress any melatonin, a hormone that [07:38] makes you sleepy that happens to be [07:39] swimming around in your bloodstream at [07:41] the time you wake up. It does a number [07:43] of other things too, including interact [07:44] with the adenosine system and kind of [07:46] wash out some of the adenosine that [07:48] might still be residual if you didn’t [07:49] sleep enough. Fundamentally speaking, [07:52] get that morning sunlight viewing. I [07:54] promise you will be grateful that you [07:57] did. It makes everybody feel better, [07:59] feel more alert, and it will greatly [08:01] assist with your ability to fall and [08:03] stay asleep later that night. You will [08:05] also want to leverage not just light but [08:08] temperature as a tool. If you are [08:11] inclined, it would be wise to try and [08:13] increase your core body temperature a [08:16] bit more quickly than it would otherwise [08:19] if you were to just, you know, shuffle [08:20] around outside, get your sunlight, maybe [08:22] read a little bit, etc. And there are [08:24] two main ways you can do that. The first [08:25] way is to get into cold water of some [08:29] sort. So this could be a cold shower of [08:30] anywhere from 1 to 3 minutes. This could [08:32] be an ice bath if that’s your thing. It [08:34] could be a cold tub or if you own a a [08:36] cold tub uh that’s specifically designed [08:39] for deliberate cold exposure. Get under [08:41] some cold water. 1 to 3 minutes of cold [08:43] water exposure will wake you up because [08:44] of that adrenaline release. And and I [08:47] want to highlight the and it will serve [08:50] to increase your core body temperature. [08:53] That’s right. If you put something cold [08:54] on the surface of your body, your brain, [08:56] a little cluster of neurons in the [08:57] so-called medial preoptic area, act as a [09:00] thermostat and say, “Ah, the external of [09:02] my body is cold and therefore I’m going [09:04] to heat up my core body temperature.” [09:06] So, this is a little bit paradoxical. [09:07] People think, oh, if you get into cold [09:09] water or an ice bath, your body [09:10] temperature is going to drop. And [09:11] indeed, that’s true. If you stay in for [09:12] a while, but if you just get in for [09:14] about 1 to 3 minutes or under the cold [09:16] shower for 1 to 3 minutes, your core [09:17] body temperature will increase. So, this [09:20] is great for waking up. And we have [09:23] exercise. One of the best ways to [09:24] increase your core body temperature [09:26] early in the day is to do exercise. I [09:28] always say the best time to exercise, at [09:30] least what the research points to, is [09:32] immediately when you wake up in the [09:33] morning. It could be a walk. So you can [09:35] get your sunlight exposure while you’re [09:37] taking a walk first thing in the [09:38] morning. It could be a light jog. It [09:40] could be skipping rope. But try and get [09:42] your core body temperature increased [09:44] first thing in the morning. And a great [09:46] way to do that is with a cold water and [09:49] or with exercise. And again, it doesn’t [09:51] have to be your full-blown workout for [09:53] the day if you’re doing workouts [09:55] consistently, which I hope everybody is [09:56] because everybody really should [09:58] exercise. Right now, you’ll notice we’re [09:59] only focused on this early part of the [10:01] day. And you might be saying, “Wait a [10:02] second. I thought this was an episode [10:03] about tools for sleep.” Well, everything [10:05] that we’re talking about doing in these [10:07] first 60 to 90 minutes of the day really [10:10] set in motion a wave of biological [10:13] cascades that carry through the entire [10:15] day and into the evening and into the [10:17] night and really do serve to optimize [10:19] sleep. So just hang in there with me. So [10:20] the next category of tool for use early [10:23] in the day is caffeine. You do not have [10:25] to drink caffeine. So what I’m about to [10:27] describe are ways to leverage caffeine [10:29] use to optimize sleep and wakefulness if [10:32] you are comfortable with caffeine. [10:34] Caffeine is something that a lot of [10:35] people consume early in the day. How [10:37] much depends on your tolerance and [10:40] there’s a lot of individual variability [10:41] here. Again, caffeine is a denosine [10:43] antagonist or effectively works as a [10:45] denosine antagonist and limits [10:47] sleepiness. And for many people, [10:49] shifting that caffeine intake from [10:51] immediately after waking in the morning [10:52] to 90 to 120 minutes gives them a much [10:55] longer arc of energy throughout the day [10:57] and they don’t feel the need to drink [10:59] more caffeine later in the afternoon. If [11:02] you do drink caffeine later in the [11:03] afternoon, really try and limit the [11:05] total amount or drink decaf. Certainly [11:07] keep the total amount to less than 100 [11:10] milligrams if you are interested in [11:11] getting into the best possible sleep. [11:13] And I say this knowing that many people, [11:15] including myself, can drink a double [11:16] espresso with 200 milligrams of caffeine [11:19] or more at 5:00 p. p.m. or even 6 PM or [11:21] after dinner and still quote unquote [11:24] fall asleep fine or still sleep fine. [11:26] There are more and more papers all the [11:27] time that point to the fact that [11:28] caffeine intake late in the day after 4 [11:32] p.m. that is can really disrupt the [11:34] architecture of your sleep. So you might [11:35] think you’re sleeping well, but you’re [11:37] not sleeping nearly as well as you could [11:38] if you avoided caffeine in those [11:40] afternoon hours. Now, some of you might [11:42] be doing your main bout of exercise [11:44] first thing in the morning and you want [11:46] your caffeine before that bout of [11:47] exercise. In that case, I say go for it. [11:50] I absolutely respect the fact that [11:52] people have different work schedules, [11:54] kids schedules, etc. So, if you want to [11:57] do some or none or all these tools, [11:58] that’s really up to you. I’m just [12:00] providing them to you in the simplest [12:02] form that I can possibly provide them. [12:04] Now, the other lever or tool that you [12:06] have available to you is food. Not just [12:08] what you eat, but when you eat. And it [12:10] turns out that if you eat early in the [12:12] day, you support a biological clock [12:15] mechanism that will make you more alert [12:17] early in the day. That said, many people [12:19] choose to fast in the early morning [12:21] hours of the day or in the first part of [12:23] the day. I’m one such person. I [12:24] generally don’t ingest any food until [12:27] about 11:00 a.m. or 12:00 noon. [12:29] Sometimes I’ll have breakfast. If people [12:30] are meeting for brunch or breakfast, I [12:32] will have breakfast for social reasons [12:34] every once in a while, but most of the [12:35] time I don’t eat until about lunchtime. [12:38] However, some people are really hungry [12:40] when they wake up in the morning. Just [12:41] know that if you eat early in the day, [12:44] you are further triggering an increase [12:46] in metabolism and in temperature that [12:49] will make you more alert. So, you don’t [12:51] have to eat early in the day, but you [12:54] can start to see how these different [12:55] tools layer together. Sunlight viewing, [12:57] exercise, cold water, eating, many of [13:00] them are converging on the same [13:01] mechanisms. In fact, when you drink [13:02] caffeine, there’s also a small increase [13:04] in body temperature due to the [13:05] adrenaline increase that it stimulates. [13:07] So all of these things can be layered on [13:09] top of one another or you can use them [13:11] individually or think about them [13:12] individually. Now food is an interesting [13:14] lever or tool because it’s not just [13:17] about when you eat, but it’s also about [13:18] what you eat. And I’ve talked a lot [13:21] about eating for energy and what that [13:23] means in terms of caloric energy versus [13:25] neural energy, etc. in previous podcast [13:27] episodes. We’re not going to focus on [13:28] that now because that’s very nuanced. [13:31] All that said, if you eat a very large [13:33] meal, it doesn’t matter if you slept [13:36] terrifically well 10 hours the night [13:38] before or if you are about to go to [13:40] sleep or if it’s the middle of the [13:42] afternoon, if your gut is full of food, [13:44] there’s just a large volume of food in [13:46] your gut, it’s going to divert a lot of [13:49] blood and other critical resources away [13:52] from other organs of your body, in [13:54] particular your brain, and you’re going [13:55] to be sleepy after eating a big meal. So [13:57] this is sort of a duh, but I think [13:59] oftentimes in the discussions about what [14:01] to eat for energy, people neglect to [14:04] consider food volume as a strong [14:06] parameter or variable in that [14:08] discussion. So if you eat a huge [14:10] breakfast, it’s likely that you’re going [14:11] to be tired immediately after eating [14:13] that breakfast, unless of course you [14:14] exercise very hard prior to that and you [14:17] metabolize all that food very quickly. [14:18] So if you do decide to eat in the first [14:20] few hours of the morning, just [14:21] understand that you are setting or you [14:23] are helping to set a food entrained as [14:26] it’s called circadian clock. Light, [14:30] temperature, timing of food intake, [14:32] movement, and exercise. All of these [14:34] things literally funnel in in a neural [14:38] sense. They funnel into this thing that [14:40] we call the circadian clock. and they [14:42] let that clock, that set of neurons, [14:44] predict when you are likely to be eating [14:47] and active and viewing sunlight the next [14:50] day and the next day and the next day. [14:51] So, what all these tools do is they [14:53] really set up a cascade. Think of it as [14:56] kind of a wavefront of wakefulness and [14:58] focus throughout the day. It’ll take you [14:59] through the middle of the day in the [15:01] afternoon stages we’ll talk about in a [15:02] few minutes, but really they take you to [15:05] this period that is about 5:00 p.m. [15:08] until your bedtime. A second critical [15:10] period in which you need to leverage [15:12] particular tools in order to get and [15:14] stay asleep optimally and to be able to [15:17] sleep through the night. So really, [15:19] there are three critical periods [15:20] throughout each 24-hour cycle. And [15:22] during each of those critical periods, [15:24] you’re going to want to do as many [15:26] specific things as you can to optimize [15:28] your wakefulness and focus and mood [15:30] throughout the day and your sleep at [15:32] night. The first critical period is the [15:34] one that we’ve been talking about up [15:34] until now. Things like morning sunlight, [15:36] viewing caffeine, 90 to 120 minutes [15:38] after waking, exercise, and so on. And [15:40] it really encompasses the time from [15:42] which you wake up until about 3 hours [15:45] after waking. The second critical period [15:47] is the time throughout the day and [15:50] afternoon leading into evening. So you [15:52] may ask, what are the things that you [15:53] can do throughout the day, the middle of [15:55] your day and into the afternoon and [15:56] evening hours that are really going to [15:58] set you up for the best possible sleep [15:59] later that night? Well, there are a few [16:02] dos and there are a few don’ts. First of [16:04] all, be careful about ingesting too much [16:06] caffeine throughout the middle of the [16:08] day. That’s kind of an obvious one for [16:09] the reasons that we talked about [16:10] earlier. Second of all, if you are a [16:12] napper, and I raise my hand now for [16:14] those of you listening, I’m raising my [16:15] right hand because I love naps. I’ve [16:17] always loved naps. Should you nap? [16:19] Should you not nap? That’s a question [16:21] that I get asked a lot and that I asked [16:22] Dr. Matthew Walker when he was a guest [16:24] on this podcast. Here was his answer. [16:26] And here’s what the data support. It is [16:28] fine to nap in the afternoon, but don’t [16:31] nap so late in the day or for so long [16:33] that it disrupts your ability to fall [16:36] and stay asleep at night for your major [16:38] sleep bout. I should also say you do not [16:40] have to nap. It’s kind of an interesting [16:42] phenomenon that happens on these [16:44] podcasts and on social media where we’ll [16:46] talk about naps and the fact that naps [16:47] are great and don’t make them longer [16:49] than 90 minutes, but then all the [16:51] non-nappers get really worried like, [16:53] “Wait, am I supposed to nap? I don’t [16:54] like naps. I wake up groggy.” You do not [16:56] have to nap. In fact, if you can make it [16:58] through your whole day without napping, [16:59] great. More power to you. So, this [17:01] critical period throughout the day is [17:03] one in which most people are doing a lot [17:04] of stuff. They’re emailing and picking [17:06] up kids and they’re exercising and [17:07] they’re commuting and doing all sorts of [17:09] things, taking phone calls and Zooms, [17:11] etc. But if you can get that period of [17:13] deep relaxation through a nap or NSDR, [17:16] that’s going to serve you well. Try not [17:18] to drink too much caffeine, certainly no [17:19] more than 100 milligrams of caffeine [17:22] after 4 p.m. if your goal is to fall [17:24] asleep at a reasonably normal time. And [17:26] for those of you that exercise in the [17:28] afternoon, understand that if you [17:31] exercise very intensely, so this might [17:33] be weight training or running or some [17:34] other very intense exercise, typically [17:37] that’s going to further increase your [17:39] body temperature and it’s going to [17:40] so-called delay your circadian clock. [17:43] It’s going to make it such that you want [17:45] to fall asleep a little bit later, maybe [17:48] even a lot later. So if you’re [17:49] exercising in the afternoon or evening [17:52] and that’s the only time you can [17:53] exercise or that’s the time that you [17:54] prefer to exercise, great. Just know [17:56] that you are delaying your circadian [17:58] clock, you are making it such that you [18:00] will naturally want to go to sleep later [18:02] and wake up later. Contrast that with if [18:04] you exercise early in the day, say [18:07] immediately after waking up or in the [18:09] first 0 to 4 hours after waking. In most [18:13] cases, that’s not going to shift your [18:14] circadian clock much. This critical [18:17] period two or second critical period I [18:19] should say during the middle of the day [18:20] is a time in which you should be doing [18:22] certain things and avoiding doing [18:23] certain things. So that raises the [18:24] question of whether or not you should [18:25] also be getting a lot of light in [18:27] particular sunlight throughout the day. [18:28] Now on the face of it you might just [18:30] think yes you know sunlight’s great [18:31] provided we’re not getting a sunburn and [18:33] we’re not staring at the sun and [18:34] damaging our eyes we should get as much [18:36] sunlight as we possibly can. However, [18:39] because light is such a powerful [18:40] stimulus for controlling the timing of [18:42] your sleepfulness or sleepiness, I [18:44] should say, and wakefulness, [18:47] we might want to be cautious about how [18:48] much light we are viewing in the [18:50] afternoon, in particular, in the early [18:52] evening hours. Well, turns out it’s not [18:55] so straightforward viewing. So, sunlight [18:57] to the eyes, sunlight in the late [18:59] afternoon and evening hours. So again, [19:01] depends on time of year, depends on [19:03] location that you happen to be in. But [19:05] getting some sunlight in your eyes for [19:06] again maybe 5 or 10, maybe 30 minutes [19:10] depending on how much cloud cover there [19:12] is. Doing that in the afternoon serves [19:14] an additional beneficial purpose, which [19:17] is you inoculate your nervous system [19:19] against some of the negative effects of [19:22] bright artificial light or even dim [19:24] artificial light in the nighttime hours [19:28] between 10 p.m. and 4:00 a.m., which is [19:30] really critical period 3. And we’ll talk [19:31] about what to do and what to not do [19:33] during critical period 3 of every [19:35] 24-hour cycle. But to make it very clear [19:37] what I’m saying here, get that morning [19:39] sunlight in your eyes, but also get some [19:42] sunlight in your eyes in the late [19:44] afternoon and evening hours when the sun [19:46] is at so-called low solar angle, when it [19:47] starts to descend in the sky. Getting [19:49] that sunlight in your eyes in the late [19:51] afternoon and evening signals to that [19:54] clock that it’s evening time and that [19:57] sleep is coming. It also serves as a [20:00] second anchor that tells your brain and [20:02] body, hey, it’s evening. The sun is [20:04] descending. Those yellows and blues and [20:07] oranges that you see in the evening [20:08] sunsets, those signal to your brain and [20:10] body that evening is there and that [20:12] nighttime is coming. And they’re really [20:14] establishing a second reference point or [20:16] wavefront of biological signals that are [20:19] going to optimize your nighttime hours [20:21] and your transition into really terrific [20:23] sleep. So now let’s talk about what I’m [20:25] calling critical period three of each [20:28] 24-hour cycle. So this would be the [20:29] period of time of late evening. So, it [20:32] might be 6:00 p.m. for some, depending [20:34] on when you go to sleep, or 7:00 p.m. [20:36] extending into the hours in which you [20:39] decide to get into bed and go to sleep. [20:41] And then throughout the night, there are [20:42] a number of things that you’re going to [20:44] want to do, and there are a number of [20:45] things that you are going to want to [20:47] avoid doing in order to optimize your [20:49] sleep. First of all, you’re going to [20:51] want to avoid bright artificial lights [20:54] of any color. Once the sun goes down, [20:57] you would be wise to try and dim the [20:59] lights in your indoor environment. If [21:01] you are going to use light at night, and [21:03] most people do, I would encourage you to [21:06] use as little artificial light as is [21:08] required to carry out the activities you [21:10] need to require safely. If you’re [21:12] watching a television show or you’re [21:14] watching something on your computer, dim [21:16] that screen way, way down, as dim as [21:18] possible while still, of course, being [21:19] able to view what you need to view. That [21:21] bright light exposure will absolutely [21:23] quash any melatonin that happens to be [21:26] circulating in your brain and body. Now, [21:27] melatonin a lot of people think of as a [21:29] supplement, but melatonin is naturally [21:31] released as the evening comes about and [21:33] into the nighttime hours. It’s a hormone [21:35] that makes you feel sleepy and allows [21:37] you to fall asleep. So, viewing bright [21:39] light in the late evening hours and [21:41] nighttime hours is really not good for [21:44] your sleep quality and your ability to [21:46] fall and stay asleep. So, for most [21:48] people, a simple rule of thumb is going [21:50] to be avoid bright artificial lights of [21:52] all colors and in particular overhead [21:55] bright artificial lights between the [21:56] hours of 10 p.m. and 4:00 a.m. Use only [21:59] as much light as is absolutely necessary [22:01] in order to carry out the routines and [22:03] activities you need to carry out safely. [22:06] Now, that’s light, but as you recall, we [22:08] also have this tool related to [22:09] temperature. And you’re probably not [22:12] going to be surprised that the way to [22:14] leverage temperature in the evening is [22:16] the exact opposite of the way that you [22:17] want to leverage temperature early in [22:19] the day. Early in the day, temperature [22:21] increases from cold showers or exercise, [22:23] etc. wake you up. What that means is [22:25] that taking a cold shower late at night [22:27] is probably a bad idea. Rather, taking a [22:30] nice hot bath or a sauna you might think [22:32] would heat up your body. And indeed, [22:34] that’s what happens if you stay in a [22:35] very long time. But if you do hot tub or [22:37] a hot bath or a sauna in the evening and [22:40] you don’t stay in for more than 20 or 30 [22:41] minutes and you get out, you take maybe [22:43] a coolish shower or a warm shower, then [22:46] what happens is there’s a compensatory [22:48] cooling off of your core body [22:49] temperature for the reasons we discussed [22:51] earlier and your body temperature will [22:52] drop by 1 to 3° and it will make it much [22:55] easier to get into sleep. So if you’re [22:57] somebody that enjoys hot baths, hot [22:58] showers or hot tubs, evening and [23:01] nighttime is going to be the best time [23:02] to do that if your goal is to facilitate [23:05] sleep. Similarly, you should try and [23:07] make your sleeping environment pretty [23:08] cool, if not cold. Now, that doesn’t [23:10] mean you need to be cold while you’re [23:12] asleep. You can get under as many [23:14] blankets as you need, but it’s a good [23:15] idea to make your sleeping environment [23:17] cool. In fact, drop the temperature in [23:19] that sleeping environment by at least [23:20] 3°. You’ll be happy that you did. You’re [23:23] going to want to sleep in a relatively [23:24] cool or cold sleeping environment and [23:26] then layer on the blankets as needed to [23:29] stay asleep. If you lower the [23:31] temperature in your sleeping [23:32] environment, so lower the temperature in [23:33] that room or use a controllable mattress [23:36] cover that can cool down like eight or [23:38] something of that sort, it’s naturally [23:39] going to make your sleeping environment [23:41] cooler. And if you’re too warm under the [23:44] blankets, all you have to do is extend a [23:45] hand or a foot out from under those [23:47] blankets. Whereas, if the sleeping [23:49] environment that you’re in is too warm, [23:50] there’s very little you can do to cool [23:52] off besides push off those blankets. But [23:54] if the room is too warm, well, what are [23:56] you going to do? You’d probably have to [23:57] put your hands into some cool water, [23:58] take a coolish shower or something for a [24:01] couple of seconds. That’s not very [24:02] practical. I would be remiss if I didn’t [24:04] touch on alcohol and CBD and THC. Many [24:08] places, but not all. THC is illegal, [24:11] although there are medical uses and some [24:13] places it’s um decriminalized. Other [24:15] places it’s legal. Alcohol, of course, [24:17] is consumed almost as frequently as [24:20] caffeine is consumed. The sleep that one [24:22] gets after drinking alcohol is greatly [24:25] disrupted sleep. THC and alcohol do help [24:29] some people fall asleep and maybe even [24:32] stay asleep. The architecture of that [24:33] sleep is suboptimal compared to the [24:36] sleep they would get without alcohol or [24:38] THC in their system. So, I’m not here to [24:40] tell you what to do or not to do. I’m [24:42] certainly not um the substance police. [24:45] That’s not my role. I’m just reporting [24:46] to you the biology. If your sleep is not [24:49] restoring you to the extent that you [24:51] feel it should or if you are regularly [24:53] relying on a drink or two in order to [24:56] fall asleep or THC in order to fall [24:58] asleep that is disrupting your total [25:01] pattern of sleep. Okay? So you’ve done [25:03] everything correctly up until now. You [25:05] got your morning routine from critical [25:06] period one. You got your afternoon [25:08] routine. You saw some sunlight in the [25:10] afternoon. You avoided caffeine in the [25:12] eight hours or 10 hours before bedtime. [25:14] You’re not drinking alcohol. you’ve [25:16] cooled down the room, uh you’re doing [25:18] all these things right, you’ve dim the [25:19] lights, etc., etc. What else can we do [25:22] in order to optimize our sleep? I always [25:24] say behavioral tools first, then look to [25:28] nutrition, then if necessary, look to [25:30] supplementation, and then if still [25:32] necessary, look to prescription drugs, [25:35] obviously prescribed by a [25:37] board-certified physician. There are [25:38] supplements that for most people will [25:40] greatly improve their ability to fall [25:43] and stay asleep. And the three main [25:45] supplements in that category or that kit [25:48] of sleep supplements, and I’ve talked [25:50] about these before, are magnesium [25:52] thriionate. So, T h reo n a t e, [25:57] apagenine, api g- e n i n, and theonine. [26:01] T h e a n i n e. Theonine. You don’t [26:04] necessarily need to take all three. [26:06] Although many people get a synergistic [26:08] effect from taking all three. You may [26:09] not even need to take even one. What I [26:12] recommend is that if you’re already [26:14] doing all the behavioral tools regularly [26:16] and you’re still having trouble falling [26:18] asleep and staying asleep, well then you [26:21] might try one of the supplements within [26:24] this sleep stack. They do have fairly [26:26] wide margins for safety. Although I [26:27] should also say anytime you’re going to [26:30] add or remove something from your [26:32] supplement protocol, your nutritional [26:33] program, you definitely want to talk to [26:35] your physician. I don’t just say that to [26:36] protect us. I say that to protect you. [26:38] For most people, the margins of safety [26:39] on these things are going to be pretty [26:40] broad. For some people, the dosages of [26:42] any one or several of the supplements I [26:44] mentioned will be zero. That is, you [26:46] won’t need them in order to get and stay [26:48] asleep most nights of your life. For [26:50] many people, however, taking 145 [26:53] milligrams of magnesium 3en8ate can be [26:56] very beneficial. Some people need to go [26:58] a little higher. Some people need to go [26:59] a little bit lower. 50 milligrams of [27:02] apagenine. And again, you could just [27:04] take the apagenine on its own. And 100 [27:07] to 400 millig of theanine taken again [27:11] alone or in combination with the other [27:13] supplements mentioned in this stack many [27:15] people find allows them to get really [27:17] drowsy and fall asleep sleep really [27:19] deeply and they feel much more refreshed [27:21] the next day and they don’t have a [27:22] groggginess. About 5% of people report [27:26] that magnesium 3 and8 really disrupts [27:29] their gut. It gives them diarrhea or [27:31] gastric distress in which case don’t [27:32] take it. Now in a slightly different [27:34] way, many people who can tolerate [27:37] magnesium 3 and8 or really thrive on [27:39] magnesium 3 and8 and like epigenine [27:42] might find that theanine even at the [27:45] lowest dose of 100 milligrams because [27:46] again the range is 100 to 400 milligrams [27:48] that theanine gives them such vivid [27:51] dreams that they actually find it [27:52] disruptive or they wake up and in the [27:54] middle of the night or they find that [27:55] the sleep that they’re getting is kind [27:56] of anxietyridden because of the [27:58] intensity of those dreams. So some [28:00] people might choose to leave theanine [28:01] out of the sleep stack and just take [28:03] magnesium 3in8 or rapenine. Again, some [28:05] people might leave magnesium 3 and8ate [28:07] out of the sleep stack. All of this is [28:09] really about finding the supplementation [28:11] protocol that’s ideal for you. I should [28:13] mention that whether or not you’re [28:14] taking one or two or three of the [28:16] components of the sleep stack. The ideal [28:18] time to take those is 30 to 60 minutes [28:20] before bedtime. That sleep stack can be [28:22] very beneficial to people. And I do [28:24] think that it’s preferable to melatonin. [28:26] First of all, melatonin is a hormone [28:28] that you indogenously make. The dosages [28:30] of melatonin that are contained in most [28:32] commercial products is far far far [28:34] greater than what we would make [28:35] indogenously. So, it’s really supra [28:38] physiological. So, that’s of concern [28:40] because melatonin is not just [28:41] responsible for making us sleepy and [28:44] fall asleep. It also does things like [28:47] interacts with other hormone systems, [28:49] testosterone and estrogen, even in the [28:50] puberty system in kids. Is taking [28:52] melatonin every once in a while a [28:54] problem for adjusting to jet lag, etc.? [28:56] Probably not. I would even say no. But [28:58] taking it chronically over time, [29:00] especially kids taking it chronically [29:02] over time, can potentially be [29:03] problematic. I do want to mention a [29:05] couple of broad contour tools that will [29:08] impact your ability to sleep really well [29:11] on a consistent basis. And the one that [29:13] impacts the most number of people is [29:15] weekends. Turns out that most everybody [29:18] feels the impulse to sleep in on the [29:20] weekend, especially if they’ve been out [29:21] late the night before. However, the data [29:24] show that keeping relatively consistent [29:27] sleep and wake times is really going to [29:29] enhance the quality and depth of your [29:31] sleep. So, if you stay out late one [29:32] night, sure, you might allow yourself to [29:35] sleep in an extra hour or so, but you [29:37] should really try to avoid sleeping in [29:39] longer than an hour beyond your normal [29:43] wake up time. it would be better to wake [29:44] up at a consistent time plus or minus an [29:46] hour and get a nap in the afternoon [29:48] provided that nap again isn’t too long. [29:51] Now, a couple of final points and [29:52] additional tools that I think are going [29:54] to be useful to everybody in particular [29:56] people who have young children or are [29:59] following a shift work schedule or who [30:02] are experiencing jet lag. Keep in mind [30:05] jet lag can be due to travel, which is [30:07] obvious, but jet lag can also be due to [30:10] getting woken up in the middle of the [30:11] night, right? Your body doesn’t know the [30:12] difference between flying to a new time [30:14] zone and getting woken up in the middle [30:16] of the night. The tool that I’d like to [30:18] offer you is an understanding of [30:19] something called temperature minimum. [30:21] And I’m going to make this as simple as [30:23] possible, and I’m confident that [30:24] everyone can understand this, even if [30:25] you don’t have any science background. [30:27] Here’s the question you need to ask [30:28] yourself. What is your typical wake up [30:32] time? If your typical wake up time most [30:34] days is 7 a.m., well, then your [30:37] temperature minimum is 5:00 a.m. That’s [30:39] right. Your temperature minimum is not a [30:41] temperature. It’s a time within your [30:43] 24-hour cycle. Approximately 2 hours [30:46] before your typical wake up time, your [30:48] body is at its lowest temperature that [30:50] it will ever be in the 24-hour cycle. [30:53] That’s why it’s called your temperature [30:54] minimum. Here’s what you need to know [30:56] about your temperature minimum. If you [30:58] view bright light, exercise or drink [31:02] caffeine or all of the above in the two [31:05] to four hours before your temperature [31:08] minimum, that will delay your clock. [31:11] What that means when I say delay your [31:13] clock is it will make you want to go to [31:15] sleep later and wake up later the next [31:18] night. Okay, so let’s run this exercise [31:20] for you, the person waking up at 7 a.m. [31:22] on a regular basis. I can predict with [31:25] almost certainty that your body is going [31:27] to be at its lowest temperature at 5:00 [31:30] a.m. So, what that means is that if you [31:32] get up at 3:00 a.m. or at 4:00 a.m. and [31:36] you flip on bright lights in your house [31:38] or in your bathroom or you have a cup of [31:40] coffee or you do any kind of exercise or [31:42] you get up and head to the airport, the [31:45] mechanisms in your brain and body that [31:47] control timing of sleep and timing of [31:49] waking will shift. They will delay. It’s [31:51] as if you put your clock on hold for a [31:54] little while and then let it start [31:55] again. Okay, that’s the simplest way I [31:57] can describe it. And you will tend to [31:58] want to go to sleep later and wake up [32:01] later the following night. Now, the [32:04] opposite is true if you view bright [32:07] light, drink caffeine, or exercise or [32:10] socialize, I should say, in the hours [32:13] immediately after your temperature [32:15] minimum. So for you in this example, the [32:17] person who’s waking up at 7:00 a.m., [32:19] your temperature minimum is 5:00 a.m. If [32:21] you view bright light, exercise, maybe [32:23] have a snack, maybe not, or socialize, [32:26] move about at 5:30 or 6:00 a.m. or 7:00 [32:30] a.m., that will tend to phase advance [32:33] your clock. It will tend to basically [32:36] make you want to go to bed earlier and [32:38] wake up earlier the following night. [32:39] Now, I use this example of a person who [32:41] wakes up typically at 7:00 a.m. whose [32:43] temperature minimum is 5:00 a.m. But of [32:45] course, you need to adjust that for [32:47] yourself if you’re somebody who wakes up [32:48] at 9:00 a.m. or at 5:00 a.m., etc. Why [32:50] do I offer this as a tool? Well, this is [32:52] an immensely powerful tool if, for [32:54] instance, you are headed to a time zone [32:56] where you need to go to bed earlier and [32:58] wake up earlier once you arrive in that [33:00] time zone. What it means is in the day [33:01] or two before you leave, you can force [33:04] yourself to exercise, drink caffeine, [33:08] maybe even to eat a meal early in the [33:10] morning, or maybe you still fast early [33:11] in the morning. That’s really up to you. [33:13] But you force yourself to do the act the [33:15] activities that are going to phase [33:17] advance your clock. Whereas, if you’re [33:19] traveling to a time zone where you are [33:21] going to need to go to sleep much later [33:23] and you’re going to need to wake up much [33:26] later, even a little bit later, you can [33:28] do those things in the hours prior to [33:30] your temperature minimum. And I should [33:33] say for everybody, people who are doing [33:35] jet who are jetlagged and engaged in [33:38] shift work or not, but just for [33:39] everybody, if you need to be awake in [33:42] the middle of your sleep cycle, you [33:43] know, you’re feeding a baby or you’re um [33:46] you’re taking care of a loved one or you [33:47] need to do something that’s critical or [33:48] you need to work, use red light. Okay. [33:51] Now, for shift workers who really are [33:53] trying to stay awake all night and sleep [33:55] all day, this is not going to be ideal. [33:57] But for people that for instance need to [33:59] stay up really late one night or wake up [34:01] especially early like 3:00 a.m. to [34:02] prepare for an exam that you’re just not [34:04] ready for or to head to the airport etc. [34:07] Using red light has been shown to allow [34:10] people to be awake enough that and [34:11] obviously see what they need to see in [34:13] order to perform their activities safely [34:15] but it does not seem to disrupt the [34:17] cortisol rhythm that is the healthy [34:20] normal cortisol rhythm. Okay. So, that’s [34:22] a lot of information and a lot of tools, [34:24] and I really want to encourage everybody [34:25] to get your behaviors right, get your [34:27] nutrition right for you. I promise that [34:29] if you start to implement some or [34:31] ideally all of these tools, the quality [34:34] of your sleep will increase [34:35] tremendously. And of course, in doing [34:38] so, the quality of your daytime [34:39] alertness and your ability to focus will [34:41] improve tremendously. Again, sleep is [34:44] the absolute foundation of your mental [34:47] health, your physical health, and your [34:48] performance in all endeavors. And last, [34:51] but certainly not least, thank you for [34:53] your interest in science. [34:55] [music]