WEBVTT 1 00:00:00.200 --> 00:00:04.200 Welcome to Huberman Lab Essentials, where we revisit past episodes 2 00:00:04.400 --> 00:00:07.639 for the most potent and actionable science based tools for 3 00:00:07.799 --> 00:00:13.039 mental health, physical health, and performance. I'm Andrew Huberman, and 4 00:00:13.080 --> 00:00:16.800 I'm a professor of neurobiology and ophthalmology at Stanford School 5 00:00:16.800 --> 00:00:20.120 of Medicine. Today we're talking all about sleep and how 6 00:00:20.160 --> 00:00:24.760 to optimize your sleep. Let's consider what the perfect twenty. 7 00:00:24.399 --> 00:00:26.399 Four hour cycle would look like. 8 00:00:26.679 --> 00:00:29.199 Regardless of when you wake up in the morning, one 9 00:00:29.239 --> 00:00:31.800 of the first things that happens is that your body 10 00:00:31.800 --> 00:00:35.159 temperature is increasing, and that's just going to happen naturally. 11 00:00:35.439 --> 00:00:39.359 That increase in body temperature, in turn, causes an increase 12 00:00:39.399 --> 00:00:42.359 in the release of a hormone called cortisol. Cortisol is 13 00:00:42.399 --> 00:00:45.640 often con demonized and considered this bad thing, and indeed, 14 00:00:45.679 --> 00:00:49.280 you don't want cortisol to be chronically or consistently elevated 15 00:00:49.280 --> 00:00:52.359 throughout the day or night, but you do want cortisol 16 00:00:52.520 --> 00:00:55.000 to reach its peak early in the day, right about 17 00:00:55.000 --> 00:00:57.320 the time you wake up. One way that you can 18 00:00:57.439 --> 00:01:00.320 ensure that that cortisol peak occurs early in the day, 19 00:01:00.479 --> 00:01:02.719 right about the time that you wake up, is to 20 00:01:02.920 --> 00:01:07.480 view bright light, ideally from sunlight within the first thirty 21 00:01:07.519 --> 00:01:10.319 to sixty minutes after waking. The reason for that is 22 00:01:10.519 --> 00:01:13.879 very simple. You want to trigger that cortisol increase to 23 00:01:13.920 --> 00:01:17.920 occur very early in your day, and you don't want 24 00:01:17.959 --> 00:01:20.439 that cortisol peak to happen later, which is what will 25 00:01:20.480 --> 00:01:23.519 happen if you wait to get outside and see sunlight. 26 00:01:23.799 --> 00:01:26.319 The reason for this is that you have a set 27 00:01:26.319 --> 00:01:29.120 of neurons nerve cells in your eye. They're called intrinsically 28 00:01:29.120 --> 00:01:31.599 photosensitive melanops and cells, but you do not need to 29 00:01:31.640 --> 00:01:35.200 know that name. Those neurons respond best to bright light 30 00:01:35.640 --> 00:01:37.319 and especially right after waking. 31 00:01:37.439 --> 00:01:38.200 Early in the day. 32 00:01:38.719 --> 00:01:41.079 They are best able to signal to a set of 33 00:01:41.159 --> 00:01:43.799 neurons that reside over the roof of your mouth called 34 00:01:43.799 --> 00:01:46.120 the super chismatic nucleus, which is a cluster of neurons 35 00:01:46.120 --> 00:01:49.439 that then sends a huge number of other signals electrical 36 00:01:49.439 --> 00:01:52.239 and chemical, out to your entire body. That triggers that 37 00:01:52.280 --> 00:01:54.920 cortisol increase, provides a wake up signal for your brain 38 00:01:54.920 --> 00:01:57.879 and body, and sets in motion a timer for you 39 00:01:57.920 --> 00:01:58.359 to fall. 40 00:01:58.239 --> 00:02:00.439 Asleep later that night. Here's what you do, or at 41 00:02:00.480 --> 00:02:01.239 least here's what I do. 42 00:02:01.319 --> 00:02:03.159 I wake up in the morning and I want to 43 00:02:03.200 --> 00:02:05.599 reach for my phone, but I know that even if 44 00:02:05.599 --> 00:02:07.920 I were to crank up the brightness on that phone screen, 45 00:02:08.240 --> 00:02:11.680 it's not bright enough to trigger that cortisol spike and 46 00:02:11.719 --> 00:02:15.319 for me to be at my most alert and focused 47 00:02:15.319 --> 00:02:17.400 throughout the day and to optimize my sleep at night. 48 00:02:17.520 --> 00:02:19.639 So what I do is I get out of bed 49 00:02:19.879 --> 00:02:23.520 and I go outside. And if it's a bright, clear 50 00:02:23.599 --> 00:02:26.599 day and the sun is low in the sky or 51 00:02:26.639 --> 00:02:28.800 the sun is starting to get overhead what we call 52 00:02:28.840 --> 00:02:32.240 low solar angle, then I know I'm getting outside at 53 00:02:32.240 --> 00:02:34.719 the right time. Especially on cloudy days, you want to 54 00:02:34.719 --> 00:02:37.080 get outside and get as much light energy or photons 55 00:02:37.120 --> 00:02:39.680 in your eyes. But let's say it's a very clear 56 00:02:39.759 --> 00:02:42.360 day and I can see where the sun is, I 57 00:02:42.400 --> 00:02:45.199 do not need to stare directly into the sun. So 58 00:02:45.240 --> 00:02:47.719 the way to get this sunlight viewing early in the 59 00:02:47.800 --> 00:02:52.199 day is to look toward the sun. Never look at 60 00:02:52.240 --> 00:02:55.000 any light, sunlight or otherwise that's so bright that it's 61 00:02:55.039 --> 00:02:57.000 painful to look at because you can damage your eyes. 62 00:02:57.439 --> 00:03:01.800 But for this morning sunlight viewing, it's to not wear sunglasses. 63 00:03:01.800 --> 00:03:05.479 That's right, to not wear sunglasses. It is absolutely fine 64 00:03:05.560 --> 00:03:09.759 to wear eyeglasses or contact lenses, so called corrective lenses. 65 00:03:09.800 --> 00:03:12.719 In fact, those will serve you well in this practice 66 00:03:12.879 --> 00:03:14.919 or this tool because they will focus the light onto 67 00:03:14.960 --> 00:03:18.120 your neural retina and onto those melanopsin intrinsically photosensitive gangli 68 00:03:18.120 --> 00:03:21.639 and cells. This is grounded in the core of our physiology. 69 00:03:21.719 --> 00:03:24.439 There are literally hundreds, if not thousands, of quality peer 70 00:03:24.479 --> 00:03:27.599 reviewed papers showing that light viewing early in the day 71 00:03:28.159 --> 00:03:31.120 is the most powerful stimulus for wakefulness throughout the day, 72 00:03:31.280 --> 00:03:34.439 and it has a powerful positive impact on your ability 73 00:03:34.479 --> 00:03:36.439 to fall and stay asleep at night. So this is 74 00:03:36.479 --> 00:03:41.280 really the foundational power tool for ensuring a great night's 75 00:03:41.280 --> 00:03:43.879 sleep and for feeling more awake during the day. If 76 00:03:43.919 --> 00:03:46.919 you wake up before the sun is out, you can 77 00:03:47.080 --> 00:03:51.080 and probably should, flip on artificial lights in your internal 78 00:03:51.080 --> 00:03:53.479 home environment or apartment or wherever you happen to live. 79 00:03:53.800 --> 00:03:55.919 If your goal is to be awake, If you wake 80 00:03:55.960 --> 00:03:57.199 up at four in the morning and you need to 81 00:03:57.199 --> 00:03:59.520 be awake, well, then turn on artificial lights. If you're 82 00:03:59.560 --> 00:04:02.319 asking whether or not turning on artificial lights can replace 83 00:04:02.439 --> 00:04:07.080 sunlight at those hours, unfortunately the answer is no, unless 84 00:04:07.080 --> 00:04:09.000 you have a very special light. We'll talk about what 85 00:04:09.080 --> 00:04:12.319 kind of light the bright. Artificial lights in your home 86 00:04:12.400 --> 00:04:15.719 environment are not I repeat, are not going to be 87 00:04:15.759 --> 00:04:20.279 sufficiently bright to turn on the cortisol mechanism and the 88 00:04:20.319 --> 00:04:23.160 other wake up mechanisms that you need early in the day. 89 00:04:23.319 --> 00:04:26.480 The diabolical twist, however, is that those lights in your 90 00:04:26.480 --> 00:04:29.920 home or apartment, or even on your phone are bright 91 00:04:30.079 --> 00:04:32.839 enough to disrupt your sleep if you look at them 92 00:04:32.920 --> 00:04:34.639 too late at night or in the middle of the night. 93 00:04:35.000 --> 00:04:39.120 So there's this a symmetry in our retinal, our eye biology, 94 00:04:39.199 --> 00:04:42.120 and in our brains biology whereby early in the day, 95 00:04:42.160 --> 00:04:44.519 right around waking, you need a lot of light, a 96 00:04:44.560 --> 00:04:47.199 lot of photons, a lot of light energy, and artificial 97 00:04:47.279 --> 00:04:50.959 lights generally just won't accomplish what you need them to accomplish. 98 00:04:51.240 --> 00:04:54.079 But at night, even a little bit of artificial light 99 00:04:54.279 --> 00:04:57.120 can really mess up your so called circadian your twenty 100 00:04:57.160 --> 00:04:59.920 four hour clocks, and all these mechanisms that we're talking about. 101 00:05:00.079 --> 00:05:04.000 On cloudy days, you especially need to get outside, I repeat, 102 00:05:04.079 --> 00:05:06.839 on cloudy days, overcast days, you especially need to get 103 00:05:06.879 --> 00:05:08.759 outside and get sunlight. You just need to get more 104 00:05:08.800 --> 00:05:11.079 of it. Now, how much light and how much light 105 00:05:11.199 --> 00:05:13.920 viewing do you need? This is going to vary depending 106 00:05:13.959 --> 00:05:17.319 on person and place, literally where you live on Earth, 107 00:05:17.399 --> 00:05:19.720 whether or not there's a lot of tree cover, whether 108 00:05:19.800 --> 00:05:22.480 or not you're somebody has sensitive eyes or less sensitive eyes. 109 00:05:22.519 --> 00:05:25.639 It's really impossible for me to give an absolute prescriptive, 110 00:05:25.680 --> 00:05:28.079 but we can give some general guidelines in general. On 111 00:05:28.120 --> 00:05:31.800 a clear day, meaning no cloud cover or minimal cloud cover, 112 00:05:32.199 --> 00:05:35.879 you want to get this sunlight exposure to your eyes 113 00:05:36.199 --> 00:05:37.839 for about five. 114 00:05:37.639 --> 00:05:38.480 Minutes or so. 115 00:05:38.680 --> 00:05:40.639 Could be three minutes one day, could be seven minutes 116 00:05:40.639 --> 00:05:44.279 the next day, about five minutes. On a day where 117 00:05:44.319 --> 00:05:47.000 there's cloud cover, so the sun is just peeking through 118 00:05:47.000 --> 00:05:50.040 the clouds or it's more dense cloud cover, you want 119 00:05:50.079 --> 00:05:53.560 to get about ten minutes of sunlight exposure to your 120 00:05:53.600 --> 00:05:55.800 eyes early in the day. And on days that are 121 00:05:55.839 --> 00:05:58.959 really densely overcast or maybe even a rainy you're going 122 00:05:58.959 --> 00:06:00.800 to want to get as much which just twenty or 123 00:06:00.879 --> 00:06:04.759 thirty minutes of sunlight exposure. Just don't try and get 124 00:06:04.759 --> 00:06:08.600 this sunlight exposure through a windshield of a car or 125 00:06:08.639 --> 00:06:11.000 a window, whether or not it's tinted or otherwise. It takes 126 00:06:11.079 --> 00:06:13.680 far too long. It's simply not going to trigger the 127 00:06:13.680 --> 00:06:16.040 relevant mechanisms. Now, if you live in a part of 128 00:06:16.079 --> 00:06:19.240 the world where it's extremely dark and overcast, or the 129 00:06:19.279 --> 00:06:21.720 weather won't let you outside, or you live in a cave, 130 00:06:22.040 --> 00:06:26.000 there are sunlight simulators or daylight simulators that you can purchase. 131 00:06:26.279 --> 00:06:30.399 Those are quite expensive in general. Therefore, I suggest cheaper 132 00:06:30.480 --> 00:06:33.240 options that work just as well because they get just 133 00:06:33.279 --> 00:06:36.720 as bright, things like ring lights that are sold in 134 00:06:36.839 --> 00:06:39.480 order for people to take selfies in this kind of thing. 135 00:06:40.399 --> 00:06:42.920 A LED tablet will work pretty well. I actually have 136 00:06:43.000 --> 00:06:44.240 one of those, and I put it on my desk 137 00:06:44.319 --> 00:06:47.360 all morning, even though I still get outside and look 138 00:06:47.360 --> 00:06:50.600 at sunlight first thing in the morning. Again, also especially 139 00:06:50.639 --> 00:06:52.920 I should say on cloudy days. Many of our listeners 140 00:06:52.920 --> 00:06:55.040 live in locations throughout the world where, for instance, during 141 00:06:55.040 --> 00:06:56.879 the winter it gets very very dark, so they can't 142 00:06:56.879 --> 00:07:01.000 get sufficient sunlight. But get that morning light, ideally from sunlight, 143 00:07:01.560 --> 00:07:04.680 and take into account all the specific points that I've 144 00:07:04.720 --> 00:07:07.839 given you here. When you start doing this, you'll notice 145 00:07:07.839 --> 00:07:11.600 that your body will start to feel more energized, and 146 00:07:11.639 --> 00:07:14.839 it will feel more energized more quickly. You'll actually start 147 00:07:14.839 --> 00:07:17.800 this to notice this mechanism kicking in each day, especially 148 00:07:17.839 --> 00:07:20.439 if you're paying attention to your physiology. It's that diffuse 149 00:07:20.519 --> 00:07:23.240 very bright sunlight, that photon energy that you really want. 150 00:07:23.240 --> 00:07:25.040 That's going to set all the rhythms of your brain 151 00:07:25.079 --> 00:07:28.720 and body in the proper way, not just that cortisol peak, 152 00:07:28.759 --> 00:07:31.399 but it's going to trigger proper metabolism. It's going to 153 00:07:31.439 --> 00:07:33.000 set a timer for you to be able to fall 154 00:07:33.000 --> 00:07:36.160 asleep about sixteen hours later. It's also going to suppress 155 00:07:36.319 --> 00:07:39.240 any melatonin, a hormone that makes you sleepy that happens 156 00:07:39.279 --> 00:07:41.319 to be swimming around in your bloodstream at the time 157 00:07:41.360 --> 00:07:43.879 you wake up. It does a number of other things too, 158 00:07:44.000 --> 00:07:46.759 including interact with the adentisine system and kind of wash 159 00:07:46.759 --> 00:07:49.160 out some of the adentisine that might still be residual 160 00:07:49.199 --> 00:07:52.759 if you didn't sleep enough. Fundamentally speaking, get that morning 161 00:07:52.800 --> 00:07:57.160 sunlight viewing. I promise you will be grateful that you did. 162 00:07:57.319 --> 00:08:00.399 It makes everybody feel better, feel more alert, and it 163 00:08:00.439 --> 00:08:03.279 will greatly assist with your ability to fall and stay 164 00:08:03.319 --> 00:08:05.879 asleep later that night. I'd like to take a quick 165 00:08:05.920 --> 00:08:08.240 break and acknowledge our sponsor eight Sleep. 166 00:08:08.839 --> 00:08:10.079 Eight Sleep makes smart. 167 00:08:09.800 --> 00:08:13.279 Mattress covers with cooling, heating, and sleep tracking capacity. One 168 00:08:13.279 --> 00:08:14.920 of the best ways to ensure you get a great 169 00:08:15.000 --> 00:08:17.199 night's sleep is to make sure that the temperature of 170 00:08:17.240 --> 00:08:20.079 your sleeping environment is correct. And that's because in order 171 00:08:20.120 --> 00:08:23.199 to fall asleep and stay deeply asleep, your body temperature 172 00:08:23.240 --> 00:08:25.680 actually has to drop by about one to three degrees, 173 00:08:25.920 --> 00:08:28.480 and in order to wake up feeling refreshed and energized, 174 00:08:28.680 --> 00:08:31.439 your body temperature actually has to increase by about one 175 00:08:31.480 --> 00:08:34.840 to three degrees. Eight Sleep automatically regulates the temperature of 176 00:08:34.879 --> 00:08:37.679 your bed throughout the night according to your unique needs. 177 00:08:37.840 --> 00:08:39.879 I've been sleeping on an eight sleep mattress cover for 178 00:08:39.960 --> 00:08:43.240 nearly five years now and it has completely transformed and 179 00:08:43.279 --> 00:08:46.120 improved the quality of my sleep. The latest eight sleep 180 00:08:46.159 --> 00:08:48.320 model is the Pod five. This is what I'm now 181 00:08:48.360 --> 00:08:50.960 sleeping on and I absolutely love it. It has so 182 00:08:51.039 --> 00:08:53.919 many incredible features. For instance, the Pod five has a 183 00:08:53.919 --> 00:08:57.080 feature called Autopilot, which is an AI engine that learns 184 00:08:57.080 --> 00:08:59.360 your sleep patterns and then adjust the temperature of your 185 00:08:59.360 --> 00:09:03.039 sleeping environs across different sleep stages. It'll even elevate your 186 00:09:03.080 --> 00:09:05.080 head if you're snoring, and it makes other shifts to 187 00:09:05.080 --> 00:09:07.600 optimize your sleep. If you'd like to try eight sleep, 188 00:09:07.679 --> 00:09:10.559 go to eight sleep dot com slash Huberman to get 189 00:09:10.600 --> 00:09:12.480 up to three hundred and fifty dollars off the new 190 00:09:12.519 --> 00:09:15.720 pod five. Eight Sleep ships to many countries worldwide, including 191 00:09:15.759 --> 00:09:19.240 Mexico and the UAE. Again, that's eight sleep dot com 192 00:09:19.279 --> 00:09:22.240 slash Huberman to save up to three hundred and fifty dollars. 193 00:09:22.639 --> 00:09:25.919 You will also want to leverage not just light, but 194 00:09:26.320 --> 00:09:30.240 temperature as a tool. If you are inclined, it would 195 00:09:30.240 --> 00:09:33.399 be wise to try and increase your core body temperature 196 00:09:33.960 --> 00:09:37.120 a bit more quickly than it would otherwise if you 197 00:09:37.120 --> 00:09:39.559 were to just you know, shuffle around outside, get your 198 00:09:39.559 --> 00:09:41.519 sun light, maybe read a little bit, et cetera. And 199 00:09:41.519 --> 00:09:43.279 there are two main ways you can do that. The 200 00:09:43.279 --> 00:09:47.240 first way is to get into cold water of some sort. 201 00:09:47.320 --> 00:09:49.080 So this could be a cold shower of anywhere from 202 00:09:49.120 --> 00:09:51.279 one to three minutes. This could be an ice bath 203 00:09:51.360 --> 00:09:53.639 if that's your thing. It could be a cold tub, 204 00:09:53.799 --> 00:09:57.159 or if you own a cold tub that's specifically designed 205 00:09:57.200 --> 00:10:00.399 for deliberate cold exposure, get under some cold water. One 206 00:10:00.440 --> 00:10:02.399 to three minutes of cold water exposure will wake you 207 00:10:02.480 --> 00:10:05.519 up because of that adrenaline release. And and I want 208 00:10:05.519 --> 00:10:09.879 to highlight the and it will serve to increase your 209 00:10:09.919 --> 00:10:10.879 core body temperature. 210 00:10:10.919 --> 00:10:11.320 That's right. 211 00:10:11.399 --> 00:10:13.600 If you put something cold on the surface of your body, 212 00:10:13.639 --> 00:10:15.759 your brain, a little cluster of neurons in the so 213 00:10:15.799 --> 00:10:19.600 called medial preoptic area act as a thermostat and say, ah, 214 00:10:19.639 --> 00:10:22.399 the external of my body is cold, and therefore I'm 215 00:10:22.440 --> 00:10:24.200 going to heat up my core body temperature. 216 00:10:24.240 --> 00:10:25.480 So it's a little bit paradoxical. 217 00:10:25.519 --> 00:10:27.200 People think, oh, if you get into cold water or 218 00:10:27.200 --> 00:10:29.279 an ice bath, your body temperture is going to drop, 219 00:10:29.279 --> 00:10:31.120 and indeed that's true if you stay in for a while. 220 00:10:31.159 --> 00:10:32.480 But if you just get in for about one to 221 00:10:32.519 --> 00:10:34.559 three minutes, or under the cold shower for one to 222 00:10:34.600 --> 00:10:37.799 three minutes, your core body temperature will increase. So this 223 00:10:37.919 --> 00:10:41.759 is great for waking up and we have exercise. One 224 00:10:41.759 --> 00:10:44.000 of the best ways to increase your core body temperature 225 00:10:44.000 --> 00:10:46.120 early in the day is to do exercise. And I 226 00:10:46.159 --> 00:10:48.200 always say the best time to exercise, at least what 227 00:10:48.240 --> 00:10:51.080 the research points to is immediately when you wake up 228 00:10:51.120 --> 00:10:53.000 in the morning. It could be a walk so you 229 00:10:53.039 --> 00:10:55.759 can get your sunlight exposure while you're taking a walk 230 00:10:55.799 --> 00:10:57.840 first thing in the morning. It could be a light jog, 231 00:10:57.919 --> 00:11:00.559 it could be skipping rope, but try and get your 232 00:11:00.559 --> 00:11:03.919 core body temperature increased first thing in the morning. And 233 00:11:04.360 --> 00:11:05.759 a great way to do that is with the cold 234 00:11:05.799 --> 00:11:09.799 water and or with exercise. And again, it doesn't have 235 00:11:09.840 --> 00:11:11.840 to be your full blown workout for the day if 236 00:11:11.879 --> 00:11:14.840 you're doing workouts consistently, which I hope everybody is, because 237 00:11:14.879 --> 00:11:17.720 everybody really should exercise. Right now, you'll notice we're only 238 00:11:17.720 --> 00:11:19.559 focused on this early part of the day, and you 239 00:11:19.639 --> 00:11:21.039 might be saying, wait a second, I thought this was 240 00:11:21.080 --> 00:11:21.960 an episode. 241 00:11:21.559 --> 00:11:22.600 About tools for sleep. 242 00:11:22.879 --> 00:11:25.080 Well, everything that we're talking about doing in these first 243 00:11:25.759 --> 00:11:28.639 sixty to ninety minutes of the day really set in. 244 00:11:28.639 --> 00:11:30.960 Motion a wave of. 245 00:11:30.919 --> 00:11:34.240 Biological cascades that carry through the entire day and into 246 00:11:34.279 --> 00:11:36.159 the evening and into the night, and really do serve 247 00:11:36.200 --> 00:11:38.360 to optimize sleep. So just hang in there with me. 248 00:11:38.600 --> 00:11:41.240 So the next category of tool for use early in 249 00:11:41.279 --> 00:11:42.360 the day is caffeine. 250 00:11:42.480 --> 00:11:44.120 You do not have to drink caffeine. 251 00:11:44.159 --> 00:11:47.039 So what I'm about to describe are ways to leverage 252 00:11:47.080 --> 00:11:50.480 caffeine used to optimize sleep and wakefulness if you are 253 00:11:50.759 --> 00:11:53.200 comfortable with caffeine. Caffeine is something that a lot of 254 00:11:53.200 --> 00:11:56.559 people consume early in the day. How much depends on 255 00:11:56.639 --> 00:12:00.000 your tolerance, and there's a lot of individual variability here. Again, 256 00:12:00.159 --> 00:12:03.720 caffeine is a dniscene antagonist or effectively works as a 257 00:12:03.759 --> 00:12:07.480 dentistine antagonist and limits sleepiness. And for many people, shifting 258 00:12:07.519 --> 00:12:10.720 that caffeine intake from immediately after waking in the morning 259 00:12:10.759 --> 00:12:12.720 to ninety to one hundred and twenty minutes gives them 260 00:12:12.759 --> 00:12:15.120 a much longer arc of energy throughout the day and 261 00:12:15.159 --> 00:12:18.600 they don't feel the need to drink more caffeine later 262 00:12:18.639 --> 00:12:20.960 in the afternoon. If you do drink caffeine later in 263 00:12:21.000 --> 00:12:23.679 the afternoon, really try and limit the total amount, or 264 00:12:23.720 --> 00:12:27.559 drink decaf. Certainly keep the total amount to less than 265 00:12:27.600 --> 00:12:29.759 one hundred milligrams if you are interested in getting into 266 00:12:29.799 --> 00:12:32.240 the best possible sleep. And I say this knowing that 267 00:12:32.279 --> 00:12:35.639 many people, including myself, can drink a double espresso with 268 00:12:35.639 --> 00:12:38.480 two hundred milligrams of caffeine or more at five PM 269 00:12:38.559 --> 00:12:41.600 or even six pm or after dinner and still quote 270 00:12:41.639 --> 00:12:44.360 unquote fall asleep fine or still sleep fine. There are 271 00:12:44.440 --> 00:12:46.000 more and more papers all the time that point to 272 00:12:46.039 --> 00:12:49.759 the fact that caffeine intake late in the day, after 273 00:12:49.840 --> 00:12:52.600 four pm, that is, can really disrupt. 274 00:12:52.080 --> 00:12:53.240 The architecture of your sleep. 275 00:12:53.240 --> 00:12:54.960 So you might think you're sleeping well, but you're not 276 00:12:55.000 --> 00:12:57.240 sleeping nearly as well as you could if you avoided 277 00:12:57.279 --> 00:13:00.559 caffeine in those afternoon hours. Some of you might be 278 00:13:00.559 --> 00:13:03.600 doing your main bout of exercise first thing in the morning, 279 00:13:03.639 --> 00:13:06.000 and you want your caffeine before that bout of exercise. 280 00:13:06.080 --> 00:13:08.720 In that case, I say, go for it. I absolutely 281 00:13:08.759 --> 00:13:12.879 respect the fact that people have different work schedules, kid schedules, 282 00:13:13.159 --> 00:13:15.679 et cetera. So if you want to do some or 283 00:13:15.679 --> 00:13:17.480 none or all these tools, that's really up to you. 284 00:13:17.519 --> 00:13:20.639 I'm just providing them to you in the simplest form 285 00:13:20.639 --> 00:13:23.279 that I can possibly provide them. Now, the other lever 286 00:13:23.440 --> 00:13:25.960 or tool that you have available to you is food, 287 00:13:26.120 --> 00:13:28.279 not just what you eat, but when you eat. And 288 00:13:28.320 --> 00:13:30.440 it turns out that if you eat early in the day, 289 00:13:30.679 --> 00:13:34.679 you support a biological clock mechanism that will make you 290 00:13:34.840 --> 00:13:37.559 more alert early in the day. That said, many people 291 00:13:37.679 --> 00:13:39.840 choose to fast in the early morning hours of the 292 00:13:39.919 --> 00:13:41.480 day or in the first part of the day. I'm 293 00:13:41.480 --> 00:13:44.960 one such person. I generally don't ingest any food until 294 00:13:44.960 --> 00:13:48.240 about eleven AM or twelve noon. Sometimes I'll have breakfast 295 00:13:48.279 --> 00:13:50.440 if people are eating for brunch or breakfast. I will 296 00:13:50.600 --> 00:13:53.000 have breakfast for social reasons every once in a while, 297 00:13:53.000 --> 00:13:57.039 but most of the time I don't eat until about lunchtime. However, 298 00:13:57.120 --> 00:13:58.759 some people are really hungry when they wake up in 299 00:13:58.759 --> 00:14:01.399 the morning. Just know that if you eat early in 300 00:14:01.440 --> 00:14:05.639 the day, you are further triggering an increase in metabolism 301 00:14:05.759 --> 00:14:09.200 and in temperature that will make you more alert. So 302 00:14:09.240 --> 00:14:11.320 you don't have to eat early in the day. But 303 00:14:11.720 --> 00:14:13.960 you can start to see how these different tools layer together. 304 00:14:14.159 --> 00:14:18.200 Sunlight viewing, exercise, cold water eating, many of them are 305 00:14:18.200 --> 00:14:20.639 converging on the same mechanisms. In fact, when you drink 306 00:14:20.679 --> 00:14:23.360 caffeine there's also a small increase in body temperature due 307 00:14:23.399 --> 00:14:25.879 to the adrenaline increase that it stimulates. So all of 308 00:14:25.919 --> 00:14:28.000 these things can be layered on top of one another, 309 00:14:28.360 --> 00:14:31.279 or you can use them individually or think about them individually. Now, 310 00:14:31.279 --> 00:14:34.639 food is an interesting lever or tool because it's not 311 00:14:34.720 --> 00:14:36.639 just about when you eat, but it's also about what 312 00:14:36.720 --> 00:14:37.320 you eat. 313 00:14:37.600 --> 00:14:39.080 And I've talked a lot. 314 00:14:38.960 --> 00:14:41.399 About eating for energy and what that means in terms 315 00:14:41.440 --> 00:14:44.759 of caloric energy versus neural energy, et cetera in previous 316 00:14:44.840 --> 00:14:47.159 podcast episodes. We're not going to focus on that now 317 00:14:47.200 --> 00:14:50.440 because that's very nuanced. All that said, if you eat 318 00:14:50.480 --> 00:14:54.200 a very large meal, it doesn't matter if you slept 319 00:14:54.519 --> 00:14:57.440 terrifically well ten hours the night before, or if you 320 00:14:57.480 --> 00:14:59.519 are about to go to sleep, or if it's the 321 00:14:59.559 --> 00:15:02.279 middle of the afternoon, if your gut is full of food, 322 00:15:02.559 --> 00:15:04.559 there's just a large volume of food in your gut. 323 00:15:04.639 --> 00:15:08.080 It's going to divert a lot of blood and other 324 00:15:08.519 --> 00:15:11.679 critical resources away from other organs of your body, in 325 00:15:11.679 --> 00:15:14.519 particular your brain, and you're going to be sleepy after 326 00:15:14.559 --> 00:15:16.639 eating a big meal. So this is sort of a duh, 327 00:15:16.799 --> 00:15:19.720 But I think oftentimes in the discussions about what to 328 00:15:19.759 --> 00:15:23.720 eat for energy, people neglect to consider food volume as 329 00:15:23.759 --> 00:15:26.559 a strong parameter or variable in that discussion. 330 00:15:26.840 --> 00:15:28.519 So if you eat a huge breakfast, it's. 331 00:15:28.480 --> 00:15:30.919 Likely that you are going to be tired immediately after 332 00:15:30.960 --> 00:15:33.559 eating that breakfast, unless, of course, you exercise very hard 333 00:15:33.600 --> 00:15:36.519 prior to that and you metabolize all that food very quickly. 334 00:15:36.639 --> 00:15:38.159 So if you do decide to eat in the first 335 00:15:38.200 --> 00:15:40.559 few hours of the morning, just understand that you are 336 00:15:40.639 --> 00:15:44.399 setting or you're helping to set a food entrained as 337 00:15:44.440 --> 00:15:51.159 it's called circadian clock, light, temperature, timing of food intake, movement, 338 00:15:51.240 --> 00:15:55.559 and exercise. All of these things literally funnel in in 339 00:15:55.600 --> 00:15:58.399 a neural sense. They funnel into this thing that we 340 00:15:58.440 --> 00:16:01.639 call the circadian clock, and they let that clock, that 341 00:16:01.679 --> 00:16:04.399 set of neurons predict when you are likely to be 342 00:16:04.519 --> 00:16:08.279 eating an active and viewing sunlight the next day and 343 00:16:08.320 --> 00:16:09.919 the next day and the next day. So what all 344 00:16:09.919 --> 00:16:12.720 these tools do is they really set up a cascade. 345 00:16:13.159 --> 00:16:15.240 I'll think of it as kind of a wavefront of 346 00:16:15.279 --> 00:16:17.919 wakefulness and focus throughout the day. It'll take you through 347 00:16:17.960 --> 00:16:19.879 the middle of the day in the afternoon stage we'll 348 00:16:19.879 --> 00:16:23.000 talk about in a few minutes, but really they take 349 00:16:23.039 --> 00:16:26.519 you to this period that is about five PM until 350 00:16:26.559 --> 00:16:30.120 your bedtime, a second critical period in which you need 351 00:16:30.159 --> 00:16:32.639 to leverage particular tools in order to get and stay 352 00:16:32.679 --> 00:16:36.240 asleep optimally and to be able to sleep through the night. 353 00:16:36.399 --> 00:16:39.000 So really there are three critical periods throughout each twenty 354 00:16:39.039 --> 00:16:41.759 four hour cycle, and during each of those critical periods, 355 00:16:41.759 --> 00:16:45.039 you're going to want to do as many specific things 356 00:16:45.039 --> 00:16:47.759 as you can to optimize your wakefulness and focus and 357 00:16:47.799 --> 00:16:50.799 mood throughout the day and your sleep at night. The 358 00:16:50.799 --> 00:16:52.399 first critical period is the one that we've been talking 359 00:16:52.399 --> 00:16:54.759 about up until now. I think it's like morning sunlight, viewing, 360 00:16:54.879 --> 00:16:57.759 caffeine ninety one hundred and minutes after waking, exercise, and 361 00:16:57.799 --> 00:17:00.559 so on, and it really encompasses the time from which 362 00:17:00.559 --> 00:17:04.200 you wake up until about three hours after waking. The 363 00:17:04.279 --> 00:17:07.759 second critical period is the time throughout the day and 364 00:17:07.920 --> 00:17:10.880 afternoon leading into evening. So you may ask, what are 365 00:17:10.920 --> 00:17:12.640 the things that you can do throughout the day, the 366 00:17:12.680 --> 00:17:14.759 middle of your day and into the afternoon and evening 367 00:17:14.799 --> 00:17:16.359 hours that are really going to set you up for 368 00:17:16.359 --> 00:17:17.519 the best possible. 369 00:17:17.160 --> 00:17:18.119 Sleep later that night. 370 00:17:18.799 --> 00:17:20.839 Well, there are a few do's and there are a 371 00:17:20.880 --> 00:17:24.519 few don'ts. First of all, be careful about ingesting too 372 00:17:24.640 --> 00:17:26.599 much caffeine throughout the middle of the day. That's kind 373 00:17:26.640 --> 00:17:28.279 of an obvious one, for the reasons that we talked 374 00:17:28.319 --> 00:17:31.240 about earlier. Second of all, if you are a napper, 375 00:17:31.359 --> 00:17:33.200 and I raise my hand now for those of you listening, 376 00:17:33.200 --> 00:17:35.440 I'm raising my right hand because I love naps. 377 00:17:35.519 --> 00:17:38.480 I've always loved naps. Should you nap? Should you not nap? 378 00:17:38.599 --> 00:17:40.240 That's a question that I get asked a lot, and 379 00:17:40.240 --> 00:17:42.119 that I asked doctor Matthew Walker when he was a 380 00:17:42.119 --> 00:17:44.480 guest on this podcast. Here was his answer, and here's 381 00:17:44.480 --> 00:17:47.240 what the data support. It is fine to nap in 382 00:17:47.240 --> 00:17:50.480 the afternoon, but don't nap so late in the day 383 00:17:50.680 --> 00:17:53.200 or for so long that it disrupts your ability to 384 00:17:53.359 --> 00:17:56.400 fall and stay asleep at night for your major sleep bout. 385 00:17:56.559 --> 00:17:59.279 I should also say you do not have to to nap. 386 00:18:00.079 --> 00:18:02.640 Kind of an interesting phenomenon that happens on these podcasts 387 00:18:02.640 --> 00:18:04.640 in on social media where we'll talk about naps and 388 00:18:04.680 --> 00:18:07.240 the fact that naps are great and don't make them 389 00:18:07.279 --> 00:18:10.079 longer than ninety minutes. But then all the non nappers 390 00:18:10.119 --> 00:18:12.079 get really worried. Wait, am I supposed to nap? I 391 00:18:12.119 --> 00:18:12.759 don't like naps. 392 00:18:12.799 --> 00:18:14.960 I wake up Grogg. You do not have to nap. 393 00:18:15.039 --> 00:18:16.359 In fact, if you can make it through your whole 394 00:18:16.440 --> 00:18:18.240 day without napping, great more. 395 00:18:18.119 --> 00:18:18.640 Power to you. 396 00:18:18.880 --> 00:18:21.319 So this critical period throughout the day is one in 397 00:18:21.319 --> 00:18:23.000 which most people are doing a lot of stuff. They're 398 00:18:23.039 --> 00:18:25.720 emailing and picking up kids, and they're exercising, and they're 399 00:18:26.119 --> 00:18:28.200 commuting and doing all sorts of things, taking phone calls 400 00:18:28.200 --> 00:18:30.400 and zooms, et cetera. But if you can get that 401 00:18:30.480 --> 00:18:34.359