Using Science to Optimize Sleep, Learning & Metabolism

0:00 [upbeat music]

0:00 - Welcome to the Huberman Lab Podcast

0:01 where we discuss science

0:03 and science-based tools for everyday life.

0:09 I'm Andrew Huberman, and I'm a Professor of Neurobiology

0:12 and Ophthalmology at Stanford School of Medicine.

0:15 This podcast is separate

0:16 from my teaching and research roles at Stanford.

0:19 It is however, part of my desire and effort

0:21 to bring zero cost to consumer information

0:23 about science and science-related tools

0:25 to the general public.

0:27 Along those lines,

0:28 I want to thank the sponsors of today's podcast.

0:31 Our first sponsor is Athletic Greens, which is an all-in-one

0:34 vitamin mineral probiotic liquid supplement.

0:38 I've been using Athletic Greens since 2012

0:41 because I really like getting my total vitamin mineral

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0:49 It also tastes really good.

0:50 I mix mine with a little bit of lemon juice.

0:51 I've been doing that well over a decade now.

0:54 And the inclusion of probiotics is important to me because

0:58 there's a lot of data out there right now

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1:01 for the immune system for, mood.

1:03 And so by combining all these things in one product

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1:20 vitamin D3 has been shown to be important

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1:36 The other sponsor of today's podcast is InsideTracker.

1:39 InsideTracker is a way to measure metabolic factors,

1:44 hormones, and DNA related factors

1:48 by way of blood tests and saliva

1:50 in order to assess one's health.

1:52 I'm a big believer in blood tests and saliva tests

1:55 for assessing one's health markers, because I like data.

1:59 And there's really no other way to measure

2:02 what's going on in one's body

2:04 without taking the occasional blood test or saliva test.

2:08 You can guess what's going on

2:10 but if you really want to know what's going on under the hood

2:12 InsideTracker can be of great help.

2:15 One of the problems with a lot of products out there

2:18 or just regular blood testing

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2:23 but you don't know what to do with those data.

2:25 Great thing about InsideTracker is provided in a format.

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2:35 directs you

2:35 toward potential lifestyle related changes

2:39 like changes in exercise, or changes in sleep patterns,

2:43 or changes in nutritional patterns,

2:45 that can really help move those markers and those numbers

2:48 on those metabolic factors, hormones, et cetera

2:51 in the direction that you want.

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2:54 you can go to insidetracker.com/huberman.

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3:02 Okay, let's get started.

3:04 Today is episode three of the podcast

3:06 and it is office hours.

3:08 Office hours as many of you know, it's where students

3:11 come to the office of the professor,

3:13 sit down and ask questions,

3:15 requesting clarification about things that were confusing,

3:18 or to simply go down the route of exploring a topic

3:22 with more depth and detail.

3:25 I asked for your questions to be listed

3:27 in the comment section of the previous two episodes

3:30 of the podcast on YouTube, as well as on Instagram.

3:33 And I first of all just want to thank you

3:35 for the many questions, they are excellent.

3:37 We read them all.

3:39 We distilled from that large batch of questions

3:43 to two types of questions.

3:45 Questions that were asked very often

3:47 and were light very often with a little thumbs up like tab

3:51 as well as questions that we thought could really expand

3:53 on the topics that we've covered previously.

3:56 And today we're going to cover both of those.

3:59 If we did not get to your question, please don't despair.

4:03 We will keep track of those.

4:05 And we have several more episodes devoted to this topic

4:08 of sleep and wakefulness and learning

4:11 during the month of January, maybe even,

4:14 leaking over a little bit into the month of February.

4:16 So, we have time that's one of the unique formats

4:19 of this podcast is that we have time for dialogue,

4:21 we have time for your questions

4:22 and we have time to really go deep into these topics.

4:26 It's official Costello is sleeping in the background.

4:28 So if you hear snoring, Costello is going to be keeping time

4:33 with his deep and melodic snoring.

4:36 There he goes.

4:37 So the questions that we received, I batched crudely

4:42 into a couple of different categories,

4:44 light, exercise, supplementation, temperature, learning,

4:51 plasticity, and mood, and sort of mood related disorders.

4:55 There were a lot of questions about those.

4:57 Before we begin any of this

4:58 I want to point out something that I,

5:00 I always say it sounds like boiler plate

5:02 but it's important not just to protect me

5:04 but to protect you, which is that I am not a physician.

5:07 I'm not a medical doctor.

5:08 I don't prescribe anything, including behavioral protocols.

5:11 I'm a professor.

5:12 So I profess a lot of things

5:13 based on quality peer reviewed studies.

5:16 You should take that information.

5:18 You should filter it through whatever it is

5:20 that you currently happen to be dealing with,

5:22 whether or not that's health or illness, you should consult

5:24 with a licensed healthcare professional before you add

5:29 or remove anything from your daily life protocol.

5:33 I'm not responsible for your health.

5:35 You are, so be smart with this information

5:37 and be a stringent filter, as we say.

5:42 Okay, very well let's get started on the actual material.

5:46 Somebody asked, what is the role of moonlight and fire,

5:52 I'm presuming they mean fireplace

5:54 or candle or things of that sort, in circadian rhythms.

5:58 Is it okay to view moonlight at night

6:01 or will that wake me up?

6:02 Will a fire in my fireplace or using candle light

6:06 be too much light.

6:07 Great question, also offers me the opportunity

6:10 to share with you

6:11 what I think is a quite beautiful definition

6:14 of what light is in a quantitative sense.

6:17 So I've mentioned a few times the use of apps

6:21 and light meters and things to measure things like locks,

6:24 which sometimes are also described in terms of Kendals.

6:28 So those are the two units for measuring light intensity.

6:31 Typically lux, L-U-X is the, is the unit.

6:34 And so before we go forward and discuss this many lux

6:37 or that many lux, I want to just tell you what a lux is

6:41 because it relates to this question.

6:42 One lux equals the illumination of one square meter surface

6:48 at one meter away from a single candle.

6:52 Think about that.

6:53 So somebody actually decided at some point

6:55 that the amount of illumination at one square meter surface,

7:00 one meter away from a single candle, that equals one lux.

7:03 So when we talk about 6,000 lux of light intensity

7:08 or 10,000 lux of light intensity, now you have a kind of

7:11 a reference or a framework that would be the equivalent of,

7:14 you could think of it as 6,000 candles

7:16 all with their light intensity shown

7:19 on one square meter from one meters distance away.

7:22 Or of course, if it was a different number of lux

7:24 it would be a different number of candles.

7:26 So you get the idea.

7:27 Here's the great thing.

7:29 It turns out that moonlight, candle light,

7:33 and even a fireplace, if you have one of these roaring fires

7:35 going in the fireplace,

7:37 do not reset your circadian clock at night

7:41 and trick your brain into thinking that it's morning

7:44 even though if you've ever sat close to a fireplace

7:47 or even a candle, that light seems very bright.

7:50 And there are two reasons for that that are very important.

7:52 The first one is that these neurons in your eye

7:56 that I discussed in the previous episode

7:58 these melanopsin ganglion cells

8:00 also called intrinsically photosensitive ganglion cells.

8:03 Those cells adjust their sensitivity across the day,

8:07 and those cells respond best to the blue-yellow contrast

8:11 present in the rising and setting sun,

8:13 so-called low solar angle sun,

8:15 also discussed in the previous episode,

8:18 but those cells adjust their sensitivity such that

8:21 they will not activate the triggers in the brain

8:25 that conveyed daytime signals when they view moonlight,

8:30 even a full moon a really bright moon or fire.

8:34 Now this does raise an interesting kind of thought point,

8:37 which is, you know, a lot of people talked

8:39 about lunacy and the fact that when there's a full moon out

8:41 people act differently and behave differently.

8:44 There's a lot of lore around that.

8:45 There's actually a little bit of quality science around that

8:47 that maybe we can address in the future.

8:49 But, moonlight is typically not going to wake us up

8:53 too much, except maybe the moon is really full

8:56 and really bright, there's possibility for that.

8:59 So, providing you're not going to burn down the structure

9:01 you're in, you're not going to burn down the forest,

9:03 enjoy your, your fireplaces, enjoy your lights from candles.

9:08 And those are perfectly safe

9:09 without disrupting your circadian rhythm.

9:11 Because we talked about just how crucial it is

9:13 to avoid bright lights

9:14 between the hours of about 10:00 PM and 4:00 AM.

9:17 Except when you need to view things for sake of safety

9:21 or work or so and so forth.

9:24 I also received a lot of questions about red light.

9:27 Now, I think I was asked those questions

9:29 because red light is used

9:31 in a number of different commercial products

9:33 where these products tend to include a sheet,

9:36 of very bright red lights.

9:38 That one is supposed to view early in the day.

9:41 And there are various claims attached

9:43 to these red light devices

9:45 that they improve mitochondrial function,

9:46 that they improve metabolism there-

9:49 I'm going to be really honest and I can't name brands,

9:52 and I'm not going to name particular studies.

9:54 'Cause what I'm about to say

9:55 about these studies is not particularly unkind

10:00 but let's just say that none of the studies that I've seen

10:03 except for one that I'll talk about in a moment,

10:06 pointing to the positive effects of red light

10:09 on the visual system are published in blue ribbon journals.

10:13 They tend to be published in journals

10:15 that I had to work hard to find.

10:18 I'm not sure what the peer review and stringency level is.

10:21 Now, that's not to say red light isn't beneficial

10:23 because there is one study in particular

10:25 that came from Glen Jeffrey's Lab

10:26 at the University of College, London

10:28 it was published last year.

10:30 Glen is somebody I happen to know

10:31 is an excellent reputation, excellent vision scientist,

10:35 what this study essentially showed.

10:37 And again, this is a study that

10:39 I very much liked the data

10:40 and think it was done with very high standards.

10:43 What this study shows is that, viewing red light

10:47 for a few minutes each morning

10:51 can have positive effects on mitochondria

10:54 in a particular retinal cell type, that tends to degenerate

10:57 or decline in function with age in humans.

11:00 And that cell type is the photoreceptor.

11:02 The photoreceptor is a type of cell in your eye

11:06 that sits at the back of the eye.

11:08 It's kind of some distance away from the ganglion cells.

11:10 And it's the cell that converts light information

11:13 into electrical signals that the rest

11:14 of the retina and brain can understand.

11:17 These are vitally important cells without them,

11:20 people are blind.

11:21 And many people's vision gets worse with age.

11:24 In particular, age related macular degeneration

11:26 but also related to some other factors

11:29 including photo receptor functionality

11:32 just getting worse with time.

11:33 And what Glen showed was that red light flashes

11:37 delivered in particular early in the day

11:39 but not late in the day can help repair the mitochondria.

11:43 Now this study needs more support

11:46 from additional studies of course.

11:48 They are doing a clinical trial.

11:50 They did report on what I think it was 12 patients.

11:53 And so the work is ongoing, but that was very interesting.

11:57 And it points to some potentially really useful things

12:00 about red light.

12:01 However, most of the questions I got

12:03 about red light for sake of office hours

12:06 were about the use of red light later in the day.

12:08 So here's the deal, in principle red light

12:11 will not stimulate the melanopsin retinal neurons

12:14 that wake up the brain and circadian clock

12:17 and signal daytime.

12:19 However, most of the red lights in particular the red lights

12:21 that come on these sheets of these products

12:23 that people are supposed to view them in order to

12:26 access a number of proclaimed health effects,

12:29 those are way too bright

12:31 and would definitely wake up your body and brain.

12:34 So if you're going to use those products

12:36 and I'm not suggesting you do, or you don't,

12:38 but if that's your thing, you would want to use those

12:40 early in the day.

12:41 Who knows you might even derive some benefit

12:43 on mitochondria function in these photo receptors.

12:46 But if you're thinking about red light

12:48 for sake of avoiding the negative effects of light

12:51 later in the day and at night, then you want that red light

12:54 to be very, very dim, certainly much dimmer

12:56 than is on most of those commercial products.

13:00 Now, do you need red lights? No.

13:02 Although red lights are rather convenient

13:03 because you can see pretty well with them on,

13:05 but if they're dim, they won't wake up the circadian clock.

13:08 They won't have this dopamine disrupting thing

13:11 that we talked about in the previous podcast.

13:13 So there's a role for red light

13:14 potentially early in the day

13:15 and for mitochondrial repair in the photoreceptors,

13:18 there's a role for dim red light

13:20 later in the day and at night.

13:22 So you're starting to notice a theme here which is that,

13:24 there's no immediate prescription of look at these light,

13:28 it's look at these lights potentially

13:30 if that's what you want to do at particular times of day

13:32 and we're particular intensities.

13:34 It brings us back to the blue light issue

13:36 which is so many people are obsessed

13:37 with avoiding blue light, but you actually

13:39 want a ton of blue light early in the day

13:40 and throughout the day.

13:41 So don't wear your blue blockers then

13:43 or maybe even don't wear them at all.

13:44 And at night, it doesn't matter if you have blue blockers on

13:47 if the lights are bright enough, then you're still

13:50 going to be activating these cells and mechanisms.

13:52 I just want to add something

13:55 about the science behind the blue blocker confusion.

14:00 So these melanopsin retinal cells do react to blue light.

14:05 That that is the best stimulus

14:06 for one of these melanopsin cells, which led

14:09 to the belief that blue blockers would be a good thing

14:11 for preventing resetting of the circadian clock at night

14:13 and deleterious effects of screens, et cetera.

14:17 However, the people that made these products

14:20 fail to actually read the papers from start to finish

14:23 or if they did, they didn't comprehend a critical element

14:26 which is that most of those papers early on

14:28 took those neurons out and put them in a dish.

14:31 And when they did that, they divorced those neurons

14:34 from their natural connections in the eye.

14:37 It turns out in your IMI right now,

14:40 because that's what we care about, these cells exist

14:42 and the cells respond to blue light

14:45 but also to other wavelengths of light

14:47 because they not only respond directly to light

14:49 as they do in a dish, they also respond

14:52 to input from photo receptors.

14:55 So if you talk to anyone in the circadian biology field,

14:58 they'll tell you, "Oh, yeah this blue light thing,

15:00 has really gotten out of control."

15:01 Because people assume that blue light is the culprit

15:04 because blue light is the best stimulus.

15:06 That doesn't mean that blue light is the only stimulus

15:09 that will trigger these cells, okay?

15:10 So like many things a scientific paper can be accurate

15:14 without being exhaustive.

15:15 And a lot of claims about products can be accurate,

15:17 but not exhaustive.

15:18 So blue light during the day is great.

15:20 Get that screen light, get that sunlight

15:22 especially getting overhead lights.

15:24 I'll talk about all this in the previous podcast,

15:27 but at night you really want to avoid those bright lights.

15:30 And it doesn't matter if it's blue light or something else.

15:32 And so there was a real confusion about

15:34 the papers and the data when most

15:38 of those product recommendations were made.

15:41 Okay.

15:42 While we're on that topic, let's talk about light

15:45 in other orifices of the body.

15:48 I made a kind of a joke about this, the last podcast episode

15:51 but a couple of people wrote to me and said,

15:52 well, I've seen some claims that light delivered

15:55 to the ears into the ears or the roof of the mouth

15:59 or up the nose can be beneficial

16:00 for some setting circadian rhythms, no.

16:06 Not directly anyway.

16:07 And this is a great opportunity for us to distinguish

16:10 between what is commonly called the placebo effect

16:13 but a more important way to think about any manipulation

16:16 behavioral or otherwise that you might do is

16:19 the difference between modulation and mediation.

16:22 There are a lot of things that will modulate your biology.

16:25 Putting a couple of lights up your nose,

16:27 please don't do this.

16:29 Might modulate your biology by way

16:32 of the stress hormone that's released

16:33 when you stuffed those things up your nose.

16:35 Remember earlier a previous podcast, I said that

16:38 virtually anything we'll face shifts your circadian rhythm

16:41 if it's different and dramatic enough.

16:43 So the question is, is it the light delivered

16:47 up the nose or through the ears

16:48 or some other orifice that's mediating the process?

16:51 Is it actually tapping into the natural biology

16:54 of the system that you're trying to manipulate?

16:57 And this is where I like to distinguish

16:58 between real biology and hacks.

17:01 I don't like the word hack

17:02 or frankly neuro hacking or bio hacking.

17:05 I just don't like the term because a hack is

17:08 is using something for a purpose

17:10 for which it was not intended, right?

17:13 But where you can kind of, it's kind of a cheat

17:15 and that's not how biology works well.

17:17 So I try and distinguish

17:18 between things that really mediate biological processes

17:21 and things that Modulate them.

17:23 There are a number of commercial products out there

17:26 with some studies attached to them,

17:28 claiming that light delivered to the ears or wherever can

17:32 adjust your wakefulness or adjust your sleep.

17:34 I've looked at those papers again,

17:36 I'm probably going to lose some friends by saying this

17:38 but maybe I'll gain a few as well.

17:40 Not blue ribbon journals, frankly,

17:43 oftentimes read the small print.

17:45 There was a conflict of interest clause there

17:47 related to commercial interests.

17:49 If somebody disagrees with me outright on this

17:52 and can send to me a peer reviewed paper,

17:55 published in a quality journal

17:56 about light delivered anywhere, but the eyes of humans

18:00 that can mediate circadian, rhythms, wakefulness et cetera,

18:03 I'm more than happy to take a look at that

18:05 and change my words and stance on this

18:08 and do it publicly, of course.

18:10 But until then I'm guessing that

18:13 the proper controls were not done

18:15 of adjusting for heat that could be delivered

18:18 which can definitely shift circadian rhythms.

18:19 We're going to talk about temperature

18:21 and other things like that.

18:22 So light to the eyes folks is where these light effects work

18:26 in humans, in other animals,

18:28 they have extra ocular photo reception in humans, no.

18:32 And just be mindful, I mean,

18:33 I'm not trying to encourage people

18:34 to avoid certain products in particular

18:37 but just be mindful of this difference

18:38 between modulation and mediation.

18:41 A mediating, a process through a hard wired

18:46 or long-standing biological mechanism is really

18:48 where you're going to see the powerful effects over time.

18:51 I also, as you've probably noticed,

18:53 I really tend to favor behavioral tools

18:56 and zero cost tools first,

18:57 and getting those dialed in before you start,

19:00 plugging in and swallowing and putting things

19:04 in various places just to really figure out

19:07 how your biology works and explore that,

19:09 unless there's of course a clinical need

19:10 to take a prescribed drug in which case,

19:13 by all means, listen to your doctor.

19:15 Okay, a huge number of people asked me about

19:19 what about light through windows?

19:21 And I actually did an Instagram post about this look,

19:27 setting your circadian clock with sunlight

19:29 coming through a window is going to take 50

19:31 to 100 times longer.

19:32 If you want the date on that, I'd be happy to send you

19:36 to the various papers that were described

19:37 in the previous podcast that Jamie Zeitzer from Stanford.

19:41 And I have discussed also elsewhere

19:43 but here's really the key thing with us.

19:45 Do the experiment.

19:46 You can download the free app Light Meter.

19:49 You can have a bright day outside

19:50 or some sunlight hold up that app, take a picture.

19:53 It'll tell you how many lux now, you know what lux are.

19:56 It will tell you how many lux are in that environment.

19:58 Now close the window.

19:59 And if you want close the screen or don't open the screen

20:01 you can do all sorts of experiments.

20:02 You'll see that it will at least half the amount of lux.

20:06 And it doesn't scale linearly.

20:08 Meaning let's say I get a 10,000 lux outside,

20:13 5,000 looking out through an open window

20:15 and then I closed the window and it's 2,500 lux.

20:18 It does not mean that you just need to view that sunlight

20:20 for twice as long if it's half as many lux, okay?

20:25 It's not like 2,500 lux means you need to look

20:29 for 10 minutes

20:29 and 5,000 lux means you look for five minutes.

20:33 It doesn't scale that way

20:34 just because the biology doesn't work that way.

20:37 Best thing to do is to get outside, if you can,

20:39 if you can't next best thing to do

20:40 is to keep that window open.

20:42 It is perfectly fine to wear prescription lenses

20:45 and contacts.

20:46 Why is it okay to wear prescription lenses and contacts,

20:49 when those are glass also,

20:50 but looking through a window, diminishes the effect.

20:54 Well, we should think about this.

20:56 The lenses that you wear in front of your eyes

20:58 by prescription or on your eyes

21:00 are designed to focus the light on to your neural retina.

21:03 In fact, that's what near-sightedness is, is when the image

21:06 because your lens doesn't work quite right.

21:09 The image falls in front of the neural retina,

21:11 wearing a particular lens in front of that

21:14 focuses the lens onto your retina onto these very neurons.

21:17 So they can communicate that to the brain.

21:19 It's Costello is loving this light.

21:21 He's deep in sleep.

21:23 And if we, maybe we could play him some tones

21:25 and he'll remember it later, based on the studies,

21:27 we're going to talk about in a little bit.

21:30 I don't know how we'd know if he remembered it or not,

21:32 but prescription lenses are fine.

21:35 In fact, they're great for this reason

21:36 they're actually focusing the light onto the retina.

21:39 So think about this logically

21:41 and all of a sudden it makes perfect sense your glass window

21:44 or your windshield or the side window of your car,

21:48 it isn't optically perfect to bring the image

21:53 and the light onto your retina.

21:54 In fact, what it's doing is it's scattering

21:56 and filtering light in particular

21:57 the wavelengths of light that you want.

21:59 So, if you live in a low light environment

22:02 lots of questions about this.

22:04 We talked about this, the previous podcast

22:05 but just get outside for longer or,

22:09 and/or use really bright lights inside.

22:12 Okay, so let's think about

22:14 why I'm making some of these recommendations

22:17 because I think it can really empower you

22:20 with the ability to change your behavior

22:23 in terms of light viewing and other things,

22:26 depending on time of year,

22:28 depending on other lifestyle factors.

22:32 The important point to understand is that early in the day,

22:34 your central circadian clocks

22:36 and all these mechanisms are looking for a lot of light.

22:40 I mean, they don't have a mind of their own,

22:41 but it needs a lot of light to trigger this daytime signal,

22:45 alertness et cetera.

22:47 And early in the day, but not in the middle of the day,

22:51 you can sum or add photons.

22:53 So there's this brief period of time early in the day,

22:56 when the sun is low in the sky

22:58 when your brain and body are expecting

23:00 a morning wake up signal

23:02 where let's say, it's not that bright outside.

23:04 Someone sent me a picture or a little movie of their walk

23:07 in England, and it was pretty overcast

23:10 and they were using light meter and they said

23:11 it's only about 700 lux or maybe even less.

23:15 And I said, well, stay outside longer.

23:17 But when you get inside, turn on the lights really bright

23:20 and overhead lights in particular,

23:21 because those will be best for stimulating these mechanisms.

23:25 And that's because at least

23:27 for the first few hours of the day,

23:28 you can continue to some or add photon activation

23:32 of the cells in the eye and the brain.

23:35 In the middle of the day, once the sun is overhead, or even

23:37 if you stay inside all morning,

23:40 and then you're in the circadian dead zone,

23:43 which sounds terrible and it is terrible.

23:45 You doesn't matter if you get a ton of artificial light

23:48 or even sunlight,

23:50 you're not going to shift your circadian clock.

23:51 You're not going to get that wake up signal.

23:53 And then in the evening, you want to think about

23:56 this whole system as being vulnerable

23:58 to even a few photons of light because of their sensitivity

24:01 to light really goes up at night.

24:03 And I talked last time about how you can protect

24:05 against that sensitivity by looking at the setting sun

24:10 and watching the evening sun,

24:12 even if it's not crossing the horizon

24:13 around the time of sunset.

24:15 And that's because it adjusts your retinal sensitivity

24:17 and your melatonin pathway

24:19 so that light is not as detrimental to melatonin at night.

24:22 Think about the afternoon sunlight viewing as kind of a,

24:26 I think of it as kind of a Netflix inoculation.

24:29 It allows me to watch a little bit

24:30 of Netflix in the evening, although it's very

24:33 hard to watch a little bit of anything on Netflix.

24:35 It seems like there's some other neuro-biological process

24:37 that going on there where I have to watch

24:40 episode after episode after episode.

24:42 But in any case, you can protect yourself

24:45 against some of that bad effect of light at night

24:49 by looking at light in the evening.

24:50 It really does adjust down the sensitivity of the system.

24:54 Okay.

24:55 I want to talk about seasonal changes

24:57 in all these things as they relate to mood and metabolism.

25:01 So depending on where you are in the world,

25:03 Northern hemisphere, Southern hemisphere

25:05 at the equator or closer to the poles,

25:07 the days and nights are going to be different lengths.

25:10 That just makes sense.

25:12 But that translates to real biological signals

25:14 that impact everything from wakefulness and sleep times

25:18 but also mood and metabolism.

25:21 So here's how this works.

25:22 Now, after seeing the previous episode of the podcast

25:25 and paying attention here, you are armed

25:29 with the knowledge to really understand how it is

25:32 that believe it or not, every cell in your body is tuned

25:36 to the movement of the planet relative to the sun.

25:39 So as all of you know,

25:41 the earth spins once every 24 hours on its axis.

25:45 So part of that day were bathed in sunlight

25:47 depending on where we are the other half of the day

25:48 or part of the day we're in darkness.

25:50 The earth also travels around the sun 365 days

25:55 is the time that it takes, one year,

25:57 to travel around that sun.

26:00 The earth is tilted.

26:02 It's not perfectly upright.

26:05 So the earth is tilted on its axis.

26:08 So depending on where we are in that 365 day journey

26:11 and depending on where we are in terms of hemisphere,

26:13 Northern hemisphere, Southern hemisphere,

26:15 some days of the year are longer than others.

26:19 Some are very short, some are very long.

26:21 If you're at the, at the equator

26:23 you experience less variation

26:24 in day length and therefore nightlife.

26:26 And if you're closer to the poles,

26:27 you're going to experience some very long days.

26:30 And you're also going to experience some very short days

26:33 depending on which poll you're at

26:34 and what time of year it is.

26:36 The simple way to put this as depending on time of year

26:38 the days are either getting shorter or getting longer.

26:41 Now, every cell in your body adjusts its biology

26:45 according to day length, except your brain, body and cells

26:51 don't actually know anything about day length.

26:53 It only knows night length.

26:55 And here's how it works.

26:57 Light inhibits melatonin powerfully.

27:01 If days are long and getting longer,

27:04 that means melatonin is reduced.

27:08 The total amount of melatonin is less

27:11 because light is more, therefore melatonin is less.

27:16 If days are getting shorter,

27:18 light can't inhibit melatonin as much,

27:21 through the summing of photon mechanisms

27:23 that we talked about before,

27:24 and that melatonin signal is getting longer.

27:28 So every cell in your body actually knows

27:31 external day length and therefore time of year

27:34 by way of the duration of the melatonin signal.

27:37 And in general, it's fair to say that in diurnal animals,

27:41 meaning animals like us that tend to be awake

27:43 during the daytime and not nocturnal animals,

27:46 which tend to be awake at night.

27:49 The longer the melatonin signal, the more depressed

27:52 not necessarily clinically depressed,

27:54 although that can happen

27:55 but the more depressed our systems tend to be.

27:59 Reproduction, metabolism, mood, turnover rates of skin cells

28:06 and hair cells all tend to be diminished

28:08 compared to the spring and summer months

28:13 for some Northern hemisphere, spring and summer months,

28:15 or the times in which days are very long.

28:17 And there's less melatonin that tends to,

28:19 in almost all animals, including humans, more breeding,

28:23 more hormone elevation of the hormones

28:26 that stimulate breeding reproduction

28:28 and fertility metabolism is up, lipid metabolism

28:35 fat-burning is up, protein synthesis is up.

28:38 These things tend to correlate with the seasons.

28:40 Now, some people are very, very

28:43 strongly tied to the seasons.

28:44 They get depressed, clinically depressed in winter

28:47 and light therapies are very useful for those people.

28:51 Some people love the winter and they're happiest in winter

28:53 and they feel kind of depressed in summer.

28:55 Although that is far more rare.

28:57 That doesn't mean depression cannot exist in the summer,

28:59 but when we're talking about seasonal depression

29:02 that tends to be true.

29:04 It's more depression in winter.

29:07 Now there's other things that correlate with seasonality.

29:09 Suicide rates tend to be highest in the spring

29:12 not in the winter,

29:13 but that has to do with some of the more

29:16 complicated and unfortunately tragic aspects of suicide

29:20 which is that oftentimes people will commit suicide

29:22 not at the very depths of their energy levels,

29:26 but as they're emerging from those depths of low energy.

29:29 So we'll talk about suicidality and mood disorders

29:32 in a later podcast season, meaning a month later.

29:36 But for now, just understand that

29:39 everybody is going through these natural fluctuations

29:41 depending on the duration of the melatonin signal.

29:44 Now this might lead you to say, "Well,

29:47 then I should just really get as much light as I can

29:49 all the time and reduce melatonin feel great all the time."

29:51 Unfortunately, doesn't work that way

29:53 because melatonin also has important effects

29:56 on the immune system.

29:58 It has important effects

30:00 on transmitter systems in the brain, et cetera.

30:03 So everybody needs to figure out for themselves

30:06 how much light they need early in the day

30:09 and how much light they need to avoid

30:12 late in the day,

30:13 in order to optimize their mood and metabolism.

30:15 There is no one size fits all prescription

30:18 because there's a range of melatonin receptors,

30:21 there are a range of everything from metabolic types

30:25 to genetic histories, family histories, et cetera.

30:29 There is no one size fits all prescription

30:31 but by understanding that light and extended day length

30:35 inhibit melatonin and melatonin tends

30:37 to be associated with a more depressed

30:39 or reduced functioning of these kinds of activity driving

30:43 and mood elevating signals,

30:45 and understanding that you have some control

30:48 over melatonin by way of light, including sunlight

30:50 but also artificial light, and that should empower you

30:53 I believe, to make the adjustments

30:55 that if you're feeling low you might ask,

30:58 how much light am I getting?

30:59 What am I getting that light?

31:01 Because sleep is also important for restoring mood, right?

31:04 So you need sleep.

31:05 You can't just, just crush melatonin across the board

31:09 and expect to feel good because

31:11 then you're not going to fall asleep and stay asleep.

31:14 Melatonin, not incidentally comes from,

31:17 is synthesized from serotonin.

31:20 Serotonin is a neurotransmitter that is associated

31:23 with feelings of well-being provided to proper levels,

31:27 but well-being of a particular kind.

31:29 Well-being associated with quiescence and calm

31:33 and the feeling that we have enough resources

31:35 in our immediate kind of conditions.

31:38 Is the kind of thing that comes from a good meal

31:40 or sitting down with friends or holding a loved one,

31:43 or conversing with somebody that you really bond with.

31:47 Serotonin does not stimulate action.

31:50 It tends to stimulate stillness.

31:53 Very different than the neuromodulator dopamine

31:56 which is a reward feel good neuromodulator

31:59 that stimulates action.

32:00 And actually dopamine is the cursor

32:05 to epinephrin, to adrenaline

32:06 which actually puts us into action.

32:08 There it's actually made from dopamine, right?

32:11 So, you can start to think how about light

32:14 as a signal that is very powerful

32:16 for modulating things like sleep and wakefulness

32:18 but also serotonin levels, melatonin levels.

32:22 And I talked about this previously

32:24 but I'll mention once more,

32:25 that light in the middle of the night

32:26 reduces dopamine levels to the point where

32:28 it can start causing problems

32:30 with learning and memory and mood.

32:32 That's one powerful reason to void bright light

32:35 in the middle of the night.

32:37 Okay.

32:38 Seasonal rhythms have a number of effects

32:41 but humans are not purely seasonal breeders.

32:44 Unlike a lot of animals, we breed all year long.

32:47 In fact, there's a preponderance of September babies

32:52 in my life, not actual babies,

32:54 because they're born in September

32:55 which means that they were conceived in December,

32:58 without knowing the details we can fairly assume that.

33:02 And December, at least in the Northern hemisphere

33:04 at days tend to be shorter and nights tend to be longer.

33:08 So clearly humans aren't seasonal breeders

33:10 but there are shifts in breeding and fertility

33:14 that exist in humans,

33:15 but also much more strongly in other animals.

33:17 So seasonal effects vary.

33:19 Some of you will experience very strong seasonal effects

33:21 others of you will not.

33:23 I think everybody should be taking care to

33:26 get adequate sunlight and to avoid bright light at night

33:29 throughout the year if possible.

33:32 Throughout this podcast and in previous episodes,

33:34 I've been mentioning neuromodulators,

33:36 things like serotonin and dopamine

33:39 which tend to buy a certain brain circuits

33:42 and things in our body to happen in certain brain circuits

33:45 and things in our body not to happen.

33:47 One of the ones I've mentioned numerous times is epinephrin

33:50 which is a neuromodulator that tends to put us into action,

33:53 make us want to move.

33:54 In fact, when it's released in high amounts in our brain

33:56 and body, it can lead to what we call stress

33:59 or the feeling of being stressed.

34:01 Several people ask me, what's the difference

34:03 between epinephrin and adrenaline.

34:06 Adrenaline is secreted from the adrenal glands

34:08 which sit right above our kidneys.

34:10 Epinephrin is the exact same molecule

34:14 except that it's released within the brain.

34:16 And so people use these phrases or these words

34:19 rather interchangeably, epi means near

34:22 or on top of sometimes and neph, neph

34:26 Anytime you see nephron or ph it means kidney.

34:29 So it means near the kidney.

34:30 So epinephrin actually means near the kidney.

34:32 So it was used originally to describe adrenaline,

34:35 but epinephrin and adrenaline are basically the same thing

34:38 and they tend to stimulate agitation and the desire to move.

34:42 That's what that's about.

34:44 Which brings us to the topic of exercise.

34:47 Got a lot of questions about exercise.

34:49 What forms of exercise are best for sleeping well?

34:53 When should I exercise et cetera.

34:56 There's a lot of them individual variability around this,

34:59 but I can talk about what I know from the science literature

35:04 and what I happened to do myself.

35:07 There are basically two forms of exercise

35:09 that we can talk about although, of course

35:10 I realize there are many different forms of exercise.

35:13 There's much more nuance to this,

35:14 but we can talk about cardiovascular exercise,

35:16 where the idea is to repeat a movement

35:18 over and over and over continuously.

35:20 So that'd be like running, biking, rowing

35:21 and cycling this kind of thing.

35:24 Or there's a resistance exercise where you're moving,

35:28 lifting, presumably putting down also

35:31 things of progressively heavier and heavier weight

35:35 that you couldn't do continuously for 30 minutes.

35:39 So cardiovascular exercise is typically

35:42 the more aerobic type exercise and resistance exercise

35:45 of course is the more anaerobic type exercise.

35:47 And yes, there's variation between the two.

35:50 Most studies of exercise have looked at aerobic exercise

35:54 because that's basically the thing that you can get a rat

35:56 or a mouse to do.

35:58 You know what's really weird about rats and mice,

35:59 they like to run on wheels so much,

36:02 that someone actually did this study,

36:04 it was published in science they put a wheel,

36:06 a running wheel in the middle of a field

36:08 and mice ran to that wheel and ran on the wheel.

36:11 They turns out that what they like is the passage

36:16 of the visual image of the bars in front of their face,

36:19 which I find kind of remarkable

36:23 and troubling because it seems so like trivial,

36:25 but anyway they love aerobic exercise.

36:27 And so most of the studies were done on these mice

36:29 that love running on wheels.

36:30 Whereas so far as it's been challenging to find

36:34 conditions in which mice really liked to lift weights

36:37 or we'll do it in a laboratory.

36:38 So any weight bearing exercise studies

36:41 really have to be done in humans.

36:43 And since humans are what we're interested in,

36:46 there are some studies looking at these two things

36:50 and when they tend to work best.

36:52 Now you will see some places aerobic exercise

36:54 is best done in the morning

36:55 and weight training is best done in the afternoon.

36:57 I think there's far more individual variation than that.

37:01 I think there are however, a couple of windows

37:04 that the exercise science literature

37:06 and the circadian literature points to as

37:09 windows related to body temperature

37:11 in which performance, injury,

37:15 in which performance is optimized

37:17 injury is reduced and so on.

37:20 And those tend to be 30 minutes after waking.

37:23 And that probably correlates with the inflection in cortisol

37:26 associated with waking whether or not

37:28 you've gotten light or not, three hours after waking,

37:31 which probably correlates to the rise in body temperature

37:34 sometime right around waking.

37:36 And the later afternoon, usually 11 hours after waking

37:40 which is when temperature tends to peak.

37:42 So some people like to exercise in the morning.

37:45 Some people like to exercise in the afternoon.

37:46 It really depends.

37:48 I think for those of us with very busy schedules,

37:51 it's advantageous to be able to do your training

37:55 whenever you have the opportunity to do it,

37:58 unless you can really control your schedule.

38:01 And so I would never want these recommendations

38:04 to seem like recommendations, what I'm really describing

38:06 are some opportunities, 30 minutes after waking,

38:09 three hours after waking or 11 hours after waking

38:13 has been shown at least in some studies

38:14 to optimize performance, reduce injury

38:17 and that sort of thing.

38:18 But you really have to figure out what works for you.

38:21 A note about working out first thing in the morning.

38:24 Last time we talked about non-photo phase shifts.

38:26 If you exercise first thing in the morning,

38:29 your body will start to develop an anticipatory circuit.

38:32 There's actually plasticity in these circadian circuits

38:35 that will lead you to want to wake up

38:37 at the particular time that you exercised

38:39 the previous three or four days.

38:41 So that can be a powerful tool

38:42 but you still want to get light exposure.

38:44 Because it turns out that light and exercise converged,

38:48 so giving even bigger, wake up signal to the brain and body.

38:52 So you might want to think about that.

38:54 Some people find if they exercise late in the day

38:56 they have trouble sleeping

38:57 in general intense exercise does that,

39:01 whereas the kind of lower intensity exercise doesn't.

39:05 I found some interesting literature

39:07 that talked about sleep need and exercise.

39:09 I found this fascinating that

39:12 if one is waking not feeling rested and recovered from

39:18 and yet sleeping the same amount that they typically have,

39:21 it's quite possible that the intensity of exercise

39:24 in the proceeding two or three days is too high.

39:27 Whereas if one can't recover

39:31 no matter how much sleep they get,

39:33 they're just sleepy all the time,

39:35 I realized these things are correlated

39:36 that the volume of training might be too high.

39:39 Now I'm not an exercise scientist.

39:40 We should probably get Andy Galpin or somebody else on here,

39:43 who's really an expert in this kind of stuff.

39:45 I do realize as soon as anyone talks about exercise

39:48 or nutrition publicly,

39:49 they're basically opening themselves up

39:51 to all sorts of challenges

39:53 because you can basically find support

39:56 for almost any protocol in the literature.

39:59 What I've looked at was two journals in particular,

40:02 International Journal Chronobiology

40:05 and journal Biological Rhythms.

40:08 Excuse me, to assess these parameters

40:12 that I I've mentioned just just a moment ago

40:14 because the studies tended to be done in humans.

40:16 They were fairly recent and they came from

40:19 groups that I recognized as well as

40:21 knowing that those journals are peer reviewed.

40:24 Many of your questions were about neural plasticity

40:27 which is the brain and nervous system's ability to change

40:30 in response to experience.

40:33 There was a question that asked whether or not

40:35 these really deep biological mechanisms around wakefulness,

40:38 time of waking sleep, et cetera

40:41 were subject to neuroplasticity and indeed they are.

40:44 Some of that plasticity is short-term

40:46 and some of it is more long-term.

40:49 There's a really good analogy here which is,

40:51 if you happen to eat on a very tight schedule

40:55 where every day say it 8:00 AM, noon and 7:00 PM

41:00 is when you eat your food not suggesting you do this

41:02 but let's say you were to do that for a couple of days.

41:05 After a few days,

41:06 you would start to anticipate those meal times

41:09 where no matter where you were in the world,

41:12 no matter what was going on in your life

41:13 about five to 10 minutes before those meal times,

41:17 you would start to feel hungry and even a little agitated,

41:19 which is your body's way

41:21 of trying to get you to forage for food.

41:24 And that's because of some peptide signals

41:26 that come from the periphery from your body,

41:29 things like hypocretin norexin

41:32 that signal to the hypothalamus

41:33 and brainstem to make you active

41:35 and alert and look for food and feel hungry.

41:38 So there's kind of an anticipatory circuit,

41:41 that's a chemical circuit, but eventually over time,

41:44 the neurons, the neural circuits

41:46 that control hypocretin orexin

41:47 would get tuned to the neural circuits

41:50 that are involved in eating and maybe even smell and taste

41:55 to create a kind of eating circuit

41:56 that's unique to your pattern, to your rhythms.

42:00 The same thing is true for these waking and exercise

42:04 and other schedules, including all trade-in schedules.

42:06 If you wake up in the morning

42:08 and start getting your sunlight, you start exercising

42:10 in the morning or you exercise in the afternoon,

42:14 pretty soon, your body will start to anticipate that

42:16 and start to secrete hormones and other signals

42:19 that prepare your body for the ensuing activity

42:22 of waking up or going to sleep.

42:24 So if you get onto a pattern or a rhythm,

42:28 even if that rhythm isn't down to the minute,

42:30 you'll find that there's plasticity in these circuits

42:33 and it becomes easier to wake up early.

42:35 If that's your thing or exercise at a particular day

42:37 if that's your thing.

42:39 That's the beauty of neuroplasticity.

42:42 A number of people ask,

42:43 "What can I do to increase plasticity?"

42:45 And that really comes in two forms.

42:48 There's plasticity that we can access in sleep

42:51 to improve rates of learning and depth of learning

42:56 from the previous day or so.

42:58 And there's this an SDR non-sleep deep breaths

43:01 that can be done without sleeping, to improve rates

43:04 of learning and depth of retention, et cetera.

43:06 So let's consider those both

43:08 and you can incorporate these protocols if you like.

43:10 Again, these are based on quality peer reviewed studies.

43:14 First, let's talk about learning in sleep.

43:17 This is based on some work that

43:18 I'll provide the reference for

43:20 that was published in the journal Science.

43:23 Excellent journal, Matt Walker also talks about some

43:26 of these studies done by others in his book "Why We Sleep".

43:30 The studies just to remind you are

43:33 structured in he following way an individual

43:36 is brought into a laboratory, Lowe does a

43:38 spatial memory task.

43:39 So there tends to be a screen

43:42 with a bunch of different objects popping up on the screen

43:45 in different locations.

43:46 So it might be a Bulldog's face that might be a cat,

43:48 and it might be an Apple than it might be a pen

43:51 in different locations.

43:52 And that sounds trivial easy

43:54 but with time you can imagine it gets pretty tough

43:56 to come back a day later and remember,

43:58 if something presented in a given location

44:01 was something you've seen before and whether or not

44:03 it was presented in that location or a different location.

44:05 If you had enough objects and changed locations enough,

44:08 this can actually be quite difficult.

44:10 In this study, the subjects either just

44:13 went through the experiment or a particular odor

44:17 was released into the room while they were learning

44:21 or a tone was played in the room while they were learning.

44:25 And then during the sleep of those subjects

44:28 the following night and the following night,

44:31 so this was done repeatedly for several nights,

44:35 the same odor or tone was played

44:38 while the subjects were sleeping.

44:41 They did this in different stages of sleep

44:43 non-REM sleep and rapid eye movement, sleep REM sleep.

44:46 They did this with just the tone in sleep.

44:50 If the subjects had the odor but not the tone,

44:54 they did it with putting the tone,

44:56 if they had had the odor while learning.

44:58 So basically all the controls,

44:59 all the things you'd want to see done to make sure

45:01 that it wasn't some indirect effects, a modulatory effect.

45:04 Okay.

45:05 And what they found was that providing the same stimulus,

45:10 the odor, if they smelled an odor or a tone

45:13 if the subjects heard a tone while learning

45:16 if they just delivered that odor or tone

45:19 while the subject slept, rates of learning

45:21 and retention of information was significantly greater.

45:26 This is pretty cool.

45:27 What this means that you can cue the subconscious brain,

45:30 and the asleep brain to learn particular things

45:33 better and faster.

45:35 So how might you implement this?

45:37 Well, you could play with this if you want.

45:39 I don't see any real challenge

45:40 to this provided the odor and is a safe one

45:43 and then doesn't wake you up

45:44 and the tone is a safe one, and doesn't wake you up.

45:49 You could do this by having a metronome, for instance,

45:52 while I'm learning something,

45:53 playing in the background or particular music

45:55 and then have that very faintly while you sleep.

45:58 So you could apply this if you like and try this.

46:01 There are a number of groups I think now

46:03 that are trying this using tactile stimulation.

46:05 So slight vibration on the wrist during learning

46:08 and then the same vibration on the wrist during sleep.

46:10 It does not appear that the sensory modality,

46:14 whether or not it's odor or auditory tone

46:17 or tactile stimulation,

46:19 some as a sensory stimulation, whether or not it matters.

46:22 It's remarkable because it really shows

46:24 that sleep is an extension of the waking state.

46:26 We've known that for a long time

46:28 but this really tethers those two

46:30 in a very meaningful and actionable way.

46:33 So I think I'll report back to you

46:35 as I learned more about these studies,

46:36 but that's what I know about them at this point.

46:39 As long as we're there

46:39 we might as well talk about dreaming

46:41 'cause I got so many questions about dreams.

46:43 A couple of you, we want to ask me what their dreams meant.

46:46 Look, I don't even know what my dreams mean half the time.

46:50 I occasionally will wake up from a dream and remember it.

46:53 If you want to remember your dreams better,

46:55 if you're somebody who has challenges

46:57 remembering your dreams, you can set your alarms

47:00 that you wake up in the middle of this

47:01 one of these 90 minute cycles which toward morning

47:03 tend to be occupied almost exclusively by REM sleep.

47:06 Remember early in the night, you have less REM sleep

47:08 than later in the night.

47:10 But you want to get as much sleep as you can

47:12 'cause that's healthy.

47:13 So I don't know that you want to wake yourself up.

47:15 Some people find that

47:17 writing down their thoughts immediately

47:19 first thing in the morning

47:19 allows them to relater spontaneously remember

47:23 their dream they had.

47:24 There's some literature on that.

47:26 The meaning of dreams is a little bit controversial.

47:28 Some people believe they have strong meaning

47:30 other people believe that they can be

47:33 just spontaneous firing of neurons that were active

47:36 in the waking state and don't have any meaning.

47:40 There are good data to show that when you learn spatial,

47:44 new spatial environments that there's a replay of those

47:47 environments, so-called place cells that fire in your brain

47:51 only when you enter a particular environment,

47:53 that those are replayed in sleep in almost direct fashion

47:57 to the way that things were activated

48:00 when you were learning that spatial task.

48:02 Dreams are fascinating, they're were paralyzed during dreams

48:05 which brings us to another question.

48:07 Somebody asked about sleep paralysis.

48:10 We are paralyzed for much of our sleep,

48:13 so-called atonia so presumably

48:15 so we don't act out our dreams.

48:16 Some people wake up and they're still paralyzed.

48:20 I've actually had this happen to me

48:22 not very many times, but a few times.

48:23 And then they jolt themselves awake

48:25 and it actually is quite terrifying.

48:27 I can say from personal experience to wake up

48:29 be wide awake and you cannot move your body at all.

48:33 It's really quite frightening.

48:34 There are a couple of things that will increase

48:37 the intrusion of atonia into the wakeful state

48:40 which is essentially means you're waking up

48:42 but you can't, you can't move.

48:44 One is marijuana, THC, a I'm not a marijuana smoker.

48:48 I'm not a copper.

48:50 I don't know the legality where you live.

48:51 So I'm not saying one thing or another about marijuana.

48:53 I'm just, the fact that I had that experience

48:56 without marijuana means that it can happen regardless,

49:00 but marijuana smokers, for whatever reason

49:02 maybe it has something to do with the cannabinoid receptors

49:06 or the serotonin receptors downstream of the motor pathways.

49:10 I don't know.

49:11 I couldn't find any literature on this

49:13 but marijuana smokers report, higher frequency

49:16 of this kind of paralysis and wakefulness

49:19 as you transition from sleep to wakefulness.

49:21 I suppose probably

49:22 one could learn to get comfortable with it.

49:24 For me, it was terrifying, 'cause I'm just

49:26 used to being able to move my limbs fortunately

49:28 and I wasn't able to, and it's a quite a thing,

49:34 let me tell you, okay.

49:36 some other questions about neuroplasticity.

49:39 So the other form of neuroplasticity

49:42 is not the neuroplasticity that you're amplifying

49:45 by listening to tones or smelling odors in sleep,

49:50 but the neuroplasticity that you can access

49:52 with non sleep deep rest.

49:54 So NSDR, non sleep deep rest

49:57 as well as short 20 minute naps,

49:59 which are very close to non sleep deep rest

50:01 because people rarely drop

50:02 into deep States of sleep during short naps,

50:05 unless they're very sleep deprived.

50:08 NSDR has been shown to increase rates of learning

50:12 when done for 20 minute bouts for a proxy-

50:16 to match an approximately 90 minute about of learning.

50:20 So what am I talking about?

50:21 90 minute cycles are these ultradian cycles

50:24 that I've talked about previously.

50:26 And we tend to learn very well by taking a 90 minute cycle

50:30 transitioning into some focus mode early in the cycle,

50:33 and it's hard to focus and then deep focus

50:35 and learning feels almost like agitation and strain

50:39 and then by the end of that 90 minute cycle,

50:41 it becomes very hard to maintain focus

50:44 and learn more information.

50:46 There's a study published in Cell Reports last year.

50:49 Great journal, excellent paper showing that

50:53 20 minute naps or light sleep

50:56 of a sort of non sleep deep rest taken immediately after

51:00 or close to it, doesn't have to be

51:01 immediately after you finished the last sentence

51:03 of learning or whatever it is, or bar of music.

51:07 But you know, a couple of minutes after transitioning

51:09 to a period of non sleep deep rest,

51:11 where you're turning off the analysis of duration path

51:14 and outcome has been shown to accelerate learning

51:17 to a significant degree.

51:19 Both the amount of information

51:20 and the retention of that information.

51:22 So that's pretty cool,

51:24 because this is a cost-free, drug-free way of

51:29 accelerating learning without having to get more sleep.

51:32 But simply by introducing these 20 minute bouts.

51:35 I would encourage people if they want to try this

51:37 to consider the 20 minutes per every 90 minutes

51:41 of ultradian learning cycle, there you're incorporating

51:43 a number of different neuroscience backed tools

51:47 90 minute cycles for focused learning.

51:50 It could be motor, it could be cognitive,

51:51 it could be musical, whatever, and then transitioned

51:55 to a 20 minute non sleep deep rest protocol.

51:58 I just want to cue you the fact that in last` episode

52:00 in the caption on YouTube, we provided links

52:03 to two different yoga nidra, non sleep deep rest protocols

52:06 as well as hypnosis protocols that are clinically backed

52:08 from my colleague David Spiegel

52:10 at Stanford Psychiatry Department.

52:14 All those resources are free.

52:16 There are also a lot of other hypnosis scripts out there.

52:20 I like the ones from Michael Sealey

52:22 S-E-A-L, I think it's E-Y, maybe it's just L-Y,

52:26 you can find them easily on YouTube,

52:28 clinical hypnosis scripts meaning not stage hypnosis.

52:31 They're not designed to get you to do anything.

52:33 In fact they're just designed to

52:35 help rewire your brain circuitry.

52:37 Now, how does hypnosis work that way?

52:39 This has a lot to do with sleep because

52:41 it engages neuro-plasticity by bringing together

52:43 two things that normally are separate from one another,

52:46 one is the alert focused wakeful state

52:49 where you activate the learning.

52:50 And then there's the deep rest where the actual

52:53 reconfiguration of the neurons and synopsis takes place.

52:57 Hypnosis brings both the focus and the deep rest component

53:01 into the same compartment of time.

53:04 It's a very unique state in that way.

53:05 So hypnosis kind of maximizes the learning about

53:10 and the non sleep deep breasts bow and combines them.

53:13 But of course that requires some guidance from a script

53:16 or from a hypnotist clinically, a trained hypnotist

53:20 and it becomes hard to acquire detailed information.

53:23 It's more about shifts in state, like fear to states of calm

53:28 or smoking to quitting smoking, anxiety around a trauma

53:34 to release of anxiety around a trauma

53:36 rather than specific information learned in hypnosis, okay?

53:40 So hypnosis seems more about modulating the circuits

53:43 that underlie state as opposed to specific information.

53:46 Although I would not be surprised

53:48 if there weren't certain forms of hypnosis

53:50 that could increase retention and learning

53:52 of specific information, but I'm not aware

53:54 of any of those protocols out there yet.

53:57 Which brings us to the next thing about learning

53:59 and plasticity which is nootropics, AKA smart drugs.

54:04 [sighs]

54:05 This is a big topic that sigh was

54:08 a sigh of concern about how to address nootropics

54:12 in a thorough enough, but thoughtful enough way.

54:16 Look, I have a lot of thoughts about nootropics.

54:19 First of all, it means smart drugs, I believe.

54:22 And I don't like that phrase because

54:24 let's just take a step back and think about exercise.

54:28 You just say, I want to be more physically fit.

54:31 What does that mean?

54:32 Does it mean I would ask for more specificity, I'd say,

54:34 Do you want to be stronger?

54:36 Okay, maybe you need to lift heavier objects progressively.

54:39 Do you want more endurance

54:41 very different protocol to access endurance.

54:43 Do you want flexibility?

54:44 Do you want explosiveness or suppleness?

54:46 Huge range of things that we call physical fitness.

54:49 Maybe you want all of those.

54:51 If we were talking about emotional fitness

54:54 we would say, well, inability to feel empathy

54:58 but probably also to disengage from empathy

55:00 because you don't want to be tethered

55:01 to other people's emotions all the time.

55:03 That's not healthy either.

55:04 You would think about being able

55:07 to access a range of emotions, but for some people

55:10 their range into the sadness regime is really quite vast

55:14 but their range into the happiness regime

55:16 might be kind of limited.

55:17 For other people who are in a manic state,

55:19 it might be, they can access all that happy stuff

55:21 but not the sadder stuff.

55:22 So I'm speaking by way of analogy here.

55:26 But if we say we're talking about cognitive

55:30 and cognitive abilities we have to ask,

55:34 okay, creativity, memory.

55:38 We tend to associate intelligence with memory.

55:41 And I think this goes back to like spelling bees

55:42 or something, the ability to retain a lot of information

55:46 and just regurgitate information

55:48 which will get you some distance

55:49 in some disciplines of life.

55:51 But it won't allow you creative thinking,

55:53 it's necessary for creative thinking.

55:55 You need a knowledge base, right?

55:57 You can't just look up everything on Google, despite what

56:00 you know, certain educators or so-called educators say,

56:03 you need a database so that you can have the raw materials

56:07 with which to be creative.

56:08 So necessary to have memory

56:10 but not sufficient to be creative, right?

56:13 The creative could have a poor memory for certain things

56:16 but certainly not for everything.

56:17 They can't have anterograde and retrograde amnesia.

56:20 They'd be like the goldfish that every time

56:22 around the tank, it, you know

56:24 I can't remember where it's at.

56:26 I actually don't know that they've ever done that experiment

56:27 by the way, but you know, so no disrespect to goldfish

56:30 but you know, so you get the idea.

56:33 You've got creativity, you have memory,

56:35 you have the ability to task switch, right?

56:37 You have the ability to

56:40 strategy development, strategy implement.

56:43 So the problem I have with the concept of a nootropic

56:45 or a smart drug is it's not specific as to what cognitive

56:50 algorithm you're trying to engage.

56:52 We need more specificity.

56:54 That said, there are elements to learning

56:57 that we've discussed here before

56:58 that are very concrete things like

57:01 the ability to focus and put the blinders

57:04 on to everything else that's happening in

57:06 around you and in your head mainly, right?

57:08 Distractions about things you should be doing,

57:10 could be doing or might be doing

57:12 and focus on what you need to do.

57:14 And then that's required for triggering the acetylcholine

57:17 neuromodulator that will then allow you to

57:21 highlight the particular synopsis that will then

57:23 later change in sleep.

57:24 So no nootropic allows you to bypass the need

57:27 for sleep in deep rest.

57:29 That's important to understand.

57:31 So I daydream about a day when people will be able

57:38 to access compounds that are safe,

57:42 that will allow them to learn better meaning,

57:44 to access information, focus better,

57:47 as well as to sleep better and activate the plasticity

57:50 from the learning about.

57:51 Right now most nootropics

57:53 tend to bundle a bunch of things together.

57:55 Most of them include some form of stimulant, caffeine.

57:59 Episode two, I'll tell you more probably

58:01 than you ever wanted to know about caffeine,

58:03 adenosine and how that works.

58:04 So refer there for how caffeine works.

58:07 But stimulants will allow you to increase focus

58:10 up to a particular point.

58:12 If you have too little alertness in your system,

58:15 you can't focus, too much however,

58:17 you start to cliff and focus drifts, okay?

58:19 So you can't just ingest more stimulant to be more focused.

58:23 It doesn't work that way.

58:24 Most nootropics also include things that increase

58:28 or a desire to increase acetylcholine.

58:30 Things like alpha GPC and other things of that sort.

58:34 And indeed, there's some evidence

58:35 that they can increase acetylcholine.

58:37 I refer you again to examine.com the website to

58:40 evaluate any supplements or compounds for their safety

58:43 and their effects in humans and animals, free website

58:48 as well as with links to studies.

58:49 So we need the focus component.

58:51 We need the alertness component.

58:52 The alertness component comes from epinephrin,

58:54 traditionally from caffeine stimulation.

58:57 The acetylcholine stimulation traditionally comes

59:00 from Coleen donors or alpha GPC, things of that sort.

59:03 And then you would want to have some sort of off switch,

59:07 because anything that's going to really

59:09 stimulate your alertness, that then provides a crash.

59:12 That crash is not a crash

59:14 into the deep kind of restful slumber

59:16 that you would want for learning,

59:18 it's a crash into the kind of,

59:22 let's just call it lopsided sleep, meaning it's deep sleep

59:26 but it lacks certain spindles and other elements

59:29 of the physiology sleep spindles,

59:31 that really engage the learning process

59:33 and the reconfiguration of synopsis.

59:35 So right now, my stance on nootropics is that

59:40 maybe, maybe for occasional use, provided it's safe for you,

59:45 I'm not recommending it, but in general

59:48 it tends to use more of a shotgun approach

59:51 than is probably going to be useful

59:53 for learning and memory in the long run.

59:56 A lot of people ask about Modafinil or armodafinil

59:59 which was designed for treatment of narcolepsy.

1:00:01 So right there, it tells you it's a stimulant.

1:00:03 And yes, there is evidence, it will improve learning memory.

1:00:05 Modafinil is very expensive.

1:00:07 Last time I checked our Modafinil

1:00:08 I think is the recent released a generic version

1:00:12 of this that's far less expensive.

1:00:14 Most of these things look a lot like amphetamine

1:00:17 and many of them have the potential for addiction

1:00:21 or can be habit forming.

1:00:24 But more importantly, a lot of those things

1:00:26 also can create metabolic effects by disruption

1:00:28 to insulin receptors and so forth.

1:00:30 So you want to approach those with a

1:00:32 strong sense of caution.

1:00:34 Now, there are the milder things that act as nootropics

1:00:37 that I mentioned, some of them like alpha GPC.

1:00:41 Some people like Gingko.

1:00:42 Gingko gives me vicious headaches, so I don't take it.

1:00:45 So people really differ.

1:00:47 Last podcast, I recommend magnesium threonate

1:00:52 if you were exploring supplements

1:00:54 I'm not recommending anything directly.

1:00:55 I'm just saying if you're exploring supplements,

1:00:57 magnesium threonate seems among the magnesiums

1:01:00 to be one of the more bioavailable and useful for sleep.

1:01:05 I recommended it actually to a good friend of mine,

1:01:07 it gave him at very low dose, he had stomach issues with it.

1:01:11 He just had to simply stop taking it.

1:01:12 So there's variability there.

1:01:14 You just, it gave him some stomach cramping

1:01:16 and just didn't feel good on it.

1:01:17 Stopped it, he felt better.

1:01:19 Other people take magnesium threonate and feel great.

1:01:22 I was asked, do magnesium need to be taken

1:01:25 with or without food or before sleep?

1:01:27 If you're going to go that route

1:01:29 it should be taken 30 to 60 minutes before sleep,

1:01:31 'cause it's designed to make you sleepy.

1:01:33 And I'm not aware that it has to be taken with food,

1:01:36 but again all of this has to be run by your doctor

1:01:38 and this is your healthcare to govern not,

1:01:42 these are not strict recommendations so look into it.

1:01:44 But magnesium threonate, most people I recommend it to

1:01:50 have benefit from it tremendously.

1:01:52 Some people can't tolerate it, so you have to find out.

1:01:55 There were a number of questions about other supplements

1:01:57 designed to access deep sleep,

1:01:59 in part to access neuroplasticity,

1:02:01 but now I'm just sort of transitioning from neuroplasticity

1:02:04 to these compounds that can regulate sleep.

1:02:07 One of them that I discussed at the end of the last podcast,

1:02:09 I got a lot of questions about is apigenin

1:02:11 A-P-I-G-E-N-I-N, apigenin.

1:02:15 If you will look in the literature

1:02:16 the way it works is it increases some of the enzymes

1:02:19 associated with GABA metabolism.

1:02:21 It actually, GABA's an inhibitory neurotransmitter.

1:02:24 It's the neurotransmitter that is increased

1:02:27 after a couple alcohol drinks containing alcohol.

1:02:31 And that shut down the forebrain.

1:02:34 Apigenin is a derivative of the camomile.

1:02:37 I think that the proper pronunciation

1:02:39 of this is metric caria kemo mila.

1:02:41 Although I always feel like

1:02:42 I should be using a Spanish accent.

1:02:44 Whenever I say something like that

1:02:47 other related things that impact the GABA system

1:02:49 and increase GABA or things like passion flower

1:02:51 which is [speaks in foreign language].

1:02:54 [chuckles] I don't know why the Italian, is that Italian.

1:02:57 Anyway, my Italian colleagues, please forgive me.

1:02:59 I have some very close Italian friends

1:03:02 and colleagues in Genoa.

1:03:04 I butchered the Italian, sorry.

1:03:06 In any event apigenin and passion flower found in a lot of,

1:03:12 a lot of supplements designed to increase sleepiness

1:03:15 and sleep because, and they work presumably

1:03:17 because they increase GABA.

1:03:18 Actually they work on chloride channels

1:03:21 rather than give you a whole lecture

1:03:22 on membrane biophysics in neurons.

1:03:24 I'll just say that when neurons are really active

1:03:27 it's because sodium ions, salt rushes into the cells

1:03:31 and causes them to fire electrically.

1:03:33 The cells tend to become less active as more chloride

1:03:36 which is a negatively charged ion.

1:03:40 This is probably taking some of you back to the

1:03:41 either the wonderful times

1:03:44 or traumas of high school physics.

1:03:46 The chloride is negatively charged so,

1:03:48 it tends to make cells less electrically positive,

1:03:51 'cause carries a negative charge

1:03:53 and hyperpolarizes the neuron.

1:03:55 So apigenin works through these increasing the activity

1:03:58 of these chloride channels.

1:03:59 Passionflower works by increasing the activity

1:04:02 of these chloride channels and GABA transmission.

1:04:04 It tends to increase this inhibitory neurotransmitter

1:04:07 that shuts off our thinking

1:04:09 our analysis of duration path and outcome.

1:04:12 So if you're going to explore these things

1:04:14 I suggest you at least know how they work.

1:04:16 You at least go to examined.com

1:04:19 that you talked to your doctor about them.

1:04:21 Some people asked about serotonin

1:04:23 for getting to sleep and staying asleep.

1:04:26 Now I understand the rationale here.

1:04:29 Just like I understand the rationale of taking something

1:04:31 like Macuna Purina or L-DOPA to increase dopamine

1:04:34 but sometimes what works on paper

1:04:36 doesn't really work in the real world.

1:04:38 I personally have tried taking a supplement

1:04:41 which was Al tryptophan, which is the precursor to serotonin

1:04:45 or five HTP, which is designed to increase,

1:04:48 it is serotonin basically.

1:04:49 You're just a one biochemical step away

1:04:52 from actually taking actual serotonin.

1:04:55 And I'll be honest the sleep that I had

1:04:57 with increased serotonin

1:04:59 by way of tryptophan or five HTP was dreadful.

1:05:01 I fell asleep almost immediately.

1:05:03 You say, well, that's great.

1:05:04 And 90 minutes later, I woke up

1:05:06 and I couldn't sleep almost for 48 hours.

1:05:08 Now that was me, I have a pretty sensitive system

1:05:10 to certain things and not to other things.

1:05:12 Some people love these things.

1:05:13 So you really have to be thoughtful

1:05:15 and explore them with that kind of awareness

1:05:18 of being thoughtful and realizing that what works for you

1:05:22 might not work for everybody

1:05:23 and what works for everybody might not work for you.

1:05:25 Okay?

1:05:26 I'd like to continue by talking about

1:05:27 the role of temperature in sleep, accessing sleep,

1:05:32 staying asleep and wakefulness.

1:05:36 But first I want to tell a joke.

1:05:38 Because I think this joke

1:05:39 really captures some of the critical things to understand

1:05:42 about any self-experimentation that you might do.

1:05:46 So this is a story that was told to me

1:05:48 by a colleague of mine who's now a professor of Caltech

1:05:51 not to be named.

1:05:53 So there's a scientist and they're in their lab.

1:05:57 And they're trying to understand

1:05:59 how the nervous system works.

1:06:01 So they go over to a tank and they pick up a frog,

1:06:04 and they take the frog and they put it down on the table

1:06:08 And they clap. [claps]

1:06:10 And the frog jumps.

1:06:12 So they think for awhile, they pick up the frog, okay.

1:06:16 They go over to the cabinet and they take out

1:06:20 a little bit of a paralytic drug and they inject it locally

1:06:24 into the back leg, set it down and clap. [claps]

1:06:29 And the frog jumps,

1:06:30 but it kind of like jumps to the side a little bit.

1:06:34 They pick it up, they inject the paralytic

1:06:36 into the other back leg.

1:06:38 They clap again, the frog jumps,

1:06:41 but it really doesn't jump well that time,

1:06:42 it kind of drags itself forward.

1:06:45 So they pick it up and they inject the paralytic

1:06:47 into the remaining two legs.

1:06:49 They set it down and they clap and the frog doesn't jump.

1:06:54 And they go,

1:06:55 "Oh my goodness! The legs are used for hearing."

1:06:59 Now they publish the paper.

1:07:02 Paper comes out in a great journal, news releases.

1:07:05 It's a really big deal, their career takes off.

1:07:08 20 years later, a really smart graduate student

1:07:11 comes along and says, "Yeah but that's loss of function.

1:07:15 It doesn't really show gain of function."

1:07:17 So let's take a closer look.

1:07:19 So they repeat the first experiment and checks out,

1:07:22 everything happens the same way, but then they take the frog

1:07:27 and they inject a drug into all four legs that turns off

1:07:32 the paralytic, right?

1:07:34 It's an antagonist.

1:07:35 They set the frog down, they clap, and the frog jumps

1:07:40 and they go, "Oh my goodness! It's true.

1:07:42 The legs really are for hearing."

1:07:45 Now, first of all, I want to make the point that

1:07:48 this is not to illustrate that science

1:07:50 is not a good practice, it is.

1:07:52 We need to do loss of function

1:07:54 and gain and function experiments.

1:07:56 But just to show that correlation and causation

1:07:59 is complicated.

1:08:00 You need to do a variety of control experiments,

1:08:02 and you really need to figure out what works for you.

1:08:04 And so while science can provide answers about what works

1:08:08 under very controlled conditions, it doesn't

1:08:11 and can never address all the situations

1:08:14 in which a given compound,

1:08:15 a given practice will or won't work.

1:08:17 And it's not just individual variability

1:08:19 is that there are a number of different factors.

1:08:21 You all of course know that light can activate

1:08:23 and shift your circadian rhythm, but so can exercise,

1:08:26 so can food.

1:08:27 The last point I want to make is an important one,

1:08:28 which is that no frogs were hurt

1:08:32 in the telling of this joke.

1:08:34 Okay. So let's continue.

1:08:35 I want to talk about temperature.

1:08:37 Temperature is super interesting as it relates to

1:08:40 circadian rhythms and wakefulness and sleep.

1:08:44 First let's take a look at what's happening to our

1:08:48 body temperature across each 24-hour cycle.

1:08:51 In general, our temperature tends to be lowest

1:08:54 right around 4:00 AM and starts creeping up around 6:00 AM,

1:08:59 8:00 AM and peaks sometime between 4:00 PM and 6:00 PM.

1:09:05 Now that varies from person to person, but in general

1:09:07 if we were to continuously monitor or occasionally monitor

1:09:10 temperature that's what we would see.

1:09:12 Now what's interesting is that even in the absence

1:09:14 of any light cues or meal cues, we would have a shift.

1:09:19 We would have an oscillation or a rhythm in our temperature.

1:09:22 They would go from high to low.

1:09:24 This is why the idea that we're all 96.8

1:09:26 and that's our correct temperature.

1:09:27 Forget that. That is no longer true.

1:09:30 It never was true.

1:09:31 It depends on what time of day you measure temperature.

1:09:34 However, there is a range which is within normal range,

1:09:37 I think most of us associate fever with somewhere around

1:09:40 100, 101 103, that's concerning.

1:09:42 And we will be very concerned

1:09:44 if temperature drop too low as well.

1:09:46 The way that the temperature rhythm that's indogenous,

1:09:50 that's within us and rhythmic no matter what,

1:09:52 the way it gets anchored to the pattern I described before,

1:09:57 or being lowest at 4:00 AM and increasing again around,

1:10:00 through the day until about four to 6:00 PM is by way

1:10:04 of entrainment or matching to some external cue,

1:10:09 which is almost always going to be light, but also exercise.

1:10:13 Now you may have experienced this temperature rhythm

1:10:17 and how quickly it can become uninterested

1:10:20 or it can fall out of entrainment.

1:10:23 Here's an experiment I wouldn't want you to do

1:10:25 but you've probably experienced this before,

1:10:28 where you wake up, it's sunny outside,

1:10:31 and maybe you have some email or some things to take care of

1:10:33 or maybe you didn't sleep that well the night before

1:10:35 and so you stay in doors.

1:10:37 You don't change anything about your breakfast,

1:10:39 you don't change anything about your within home temperature

1:10:42 or anything like that.

1:10:43 And somewhere right around 10 or 11 o'clock

1:10:45 you start feeling kind of chilled, like you're cold.

1:10:48 Well, what happened was the oscillators, the clocks

1:10:52 in your various tissues that are governed by temperature

1:10:55 and circadian rhythm are starting to split away

1:10:58 from your central clock mechanisms.

1:11:00 So it's actually important

1:11:02 that your temperature match day length.

1:11:04 Now there's another way

1:11:05 in which temperature matches, oh daytime, excuse me.

1:11:08 There's also an important way

1:11:09 in which temperature matches day length in general

1:11:12 as days get longer, it tends to be hotter out.

1:11:15 Not always, but in general, that's the way it is.

1:11:18 And as days get shorter, it tends to be colder outside.

1:11:21 So temperature and day length are also linked metabolically.

1:11:26 They're linked biologically they're linked, excuse me,

1:11:29 and atmospherically they're linked

1:11:31 for the reason that we talked about before

1:11:32 about duration of day length

1:11:34 and other climate features and so forth.

1:11:37 So one of the most powerful things

1:11:39 about setting your circadian rhythm properly

1:11:41 is that your temperature will start to fall

1:11:44 into a regular rhythm.

1:11:45 And that temperature has a very strong effect

1:11:48 on things like metabolism

1:11:50 and when you will feel most willing and interested

1:11:53 in exercising, typically the willingness to exercise

1:11:57 and engage in any kind of activity mental or physical

1:12:00 is going to be when that rise in temperature is steepest.

1:12:03 When the slope of that line is greatest.

1:12:05 That's why 30 minutes after waking

1:12:07 is one of those key windows,

1:12:08 as well as three hours after waking.

1:12:10 And then when temperature actually peaks

1:12:12 which is generally, generally about 11 hours after waking.

1:12:17 So this is why we say that temperature and circadian rhythm

1:12:21 are linked but they're actually even more linked than that.

1:12:25 We've talked before about how light enters the eye,

1:12:27 triggers activation of these melanopsin cells,

1:12:30 which then triggers activation

1:12:31 of the super charismatic nucleus,

1:12:32 the master circadian clock.

1:12:34 And then I always say the master circadian clock

1:12:36 informs all the cells and tissues of your body

1:12:38 and puts them into a nice cohesive rhythm.

1:12:41 But what I've never answered was how it actually puts them

1:12:45 into that rhythm.

1:12:46 And it does it two ways.

1:12:48 One is it secretes a peptide.

1:12:50 And peptide is just a little protein that floats

1:12:51 through the bloodstream and signals to the cells.

1:12:54 Okay, we're tuning your clock.

1:12:55 Kind of like a little, we know watch store,

1:12:57 the watch store owner would tune the clocks.

1:13:00 But the other way is it synchronizes the temperature

1:13:03 under which those cells exist.

1:13:05 So temperature is actually the effector

1:13:08 of the circadian rhythm.

1:13:10 Now this is really important because

1:13:12 changes in temperature by way of exercise, by way of eating,

1:13:16 but especially by way of exercise

1:13:18 can start to shift our circadian rhythm pretty dramatically.

1:13:22 But let's even go to in a more extreme example.

1:13:24 Nowadays, there's some interest in cold showers

1:13:28 and ice baths, not everybody is doing this I realize.

1:13:30 People seem to either love this or hate this.

1:13:33 I don't mind the cold dunk thing.

1:13:35 I get regular about this from time to time and I'll do it.

1:13:38 I haven't been doing it recently.

1:13:39 It's always painful to do the first couple of times

1:13:41 then you get kind of used to it.

1:13:43 However, I've taken people to a cold, dunk or an ice bath.

1:13:46 I have a family member who wouldn't get in

1:13:48 literally passed her toes.

1:13:50 She was like, this is just too aversive for me.

1:13:52 Some people really like the cold, people very tremendously.

1:13:55 Getting into an ice bath is very interesting

1:13:57 because you have a rebound increase in thermogenesis.

1:14:01 Now you should know from the previous episode

1:14:03 that as that temperature increases,

1:14:06 it will shift your circadian rhythm

1:14:08 and which direction it shifts your circadian rhythm

1:14:10 will depend on whether or not you're doing it

1:14:11 during the daytime or late in the day.

1:14:12 If you do it after 8:00 PM,

1:14:14 it's going to make your day longer, right?

1:14:17 Because your body and your central clocks

1:14:21 are used to temperature going up early in the day

1:14:24 and throughout the day and peaking in the afternoon.

1:14:26 If you then increase that further

1:14:29 or you simply increase it over its baseline at 8:00 PM

1:14:32 after temperature was already falling,

1:14:34 even if it's just by a half a degree or a couple of degrees

1:14:36 or you do that with exercise

1:14:37 doesn't have to be with the ice bath,

1:14:39 you are extending, you are shifting forward your phase,

1:14:42 delaying your clock.

1:14:44 You're convincing your clock

1:14:45 and therefore the rest of your body

1:14:47 that the day is still going, right?

1:14:49 You you're giving it the perception, the cellar

1:14:51 and physiological perception that the day is getting longer.

1:14:54 And you will want to naturally stay up later

1:14:57 and wake up later.

1:14:59 Now you might say, "Wait

1:15:00 I do an ice bath late at night, and I feel great.

1:15:02 And I fall deeply asleep."

1:15:04 Well, cold can trigger the release of melatonin.

1:15:07 There's a rebound increase in melatonin.

1:15:09 So that could be the cause of that effect.

1:15:11 You have to see what works for you,

1:15:13 but if you do the ice bath early in the day and then get out

1:15:17 you will experience a more rapid rise

1:15:20 or cold shower early in the day, a more rapid rise

1:15:22 in your body temperature that will phase advance your clock

1:15:27 and make it easier to get up early the following day.

1:15:30 So for those of you that are having trouble getting up

1:15:32 and this is going to almost sound laughable

1:15:34 but a cold shower first thing in the morning

1:15:36 will wake you up, but that's waking you up in the short term

1:15:40 because of a different mechanism

1:15:41 which I'll talk about in a moment,

1:15:43 but it also is shifting your clock,

1:15:44 it's phase advancing your clock

1:15:47 in a way that makes you more likely to get up

1:15:49 earlier the next day, okay?

1:15:52 So in other words, increasing your temperature

1:15:54 by getting in an ice bath or cold shower or exercising

1:15:59 which causes a compensatory increase in body temperature.

1:16:03 Think about the normal pattern of body temperature.

1:16:05 Low around 4:35 AM starts to peak right around waking start,

1:16:09 excuse me, starts to increase right around waking

1:16:11 then steep slope, steep slope to a peak

1:16:13 around four to 6:00 PM and then drops off.

1:16:16 If you introduce an increase in body temperature

1:16:18 by way of cold exposure early in the day,

1:16:21 let's say 6:00 AM or 5:00 AM

1:16:24 if you're masochistic enough to get into a cold shower

1:16:27 at that time more power to you,

1:16:28 it's going to make, you want to wake up about half hour

1:16:31 to an hour earlier the next day than you normally would.

1:16:34 Whereas if you do it while your temperature is falling,

1:16:37 it will tend to delay and make your body perceive

1:16:39 as if the day is getting longer.

1:16:41 These are phase advances and phase delays.

1:16:43 We're going to get into this in far more detail

1:16:45 when we talk about jet lag and shift work in episode four

1:16:48 as well as other other things.

1:16:50 But temperature is,

1:16:52 again is not just one tool to manipulate

1:16:55 wake up time and circadian rhythm and metabolism.

1:16:58 It is the effector.

1:17:00 It is the way that the central circadian clock

1:17:02 impacts all the cells and tissues of your body.

1:17:04 If you want to read further about this

1:17:06 and you're really curious about the role of temperature

1:17:08 work by Joe Takahashi

1:17:09 who used to be at Northwestern University

1:17:12 and is now at UT Southwestern in Dallas,

1:17:15 incredible scientist and has really worked out

1:17:19 a lot of the mechanisms around temperature

1:17:20 in circadian rhythms.

1:17:22 You can just Google his name

1:17:23 and you'll see a whole bunch of studies there.

1:17:27 I want to talk about cold and cold exposure

1:17:30 because there's a great misconception about this

1:17:32 that actually you can leverage once you understand

1:17:35 how to use cold to either increase thermogenesis

1:17:39 and fat loss, metabolism,

1:17:42 or you can use it for stress, mitigation and mood.

1:17:45 And it really depends on one simple feature

1:17:47 of how you approach the ice bath or cold shower.

1:17:51 If you get into an ice bath or cold shower

1:17:54 and you are calming yourself you're actively calming

1:17:57 the autonomic nervous system.

1:17:58 Maybe through some deep breathing,

1:17:59 maybe through visualization, maybe you sing a song.

1:18:02 You know, people do this stuff.

1:18:04 They use various tools.

1:18:05 Some people find paying attention

1:18:07 to an external stimulus is more helpful.

1:18:09 You know, thinking about something

1:18:11 not the experience of the cold,

1:18:12 other people find that directly experiencing the cold

1:18:14 in its most intense form and kind of "going into the cold"

1:18:18 is the best way to approach it.

1:18:19 It really varies for people.

1:18:21 There's no right or wrong way to go about this.

1:18:24 But the goal of using cold exposure for stress inoculation

1:18:28 and to raise your stress threshold

1:18:30 to be able to tolerate heightened levels

1:18:32 of real life stress, not the ice bath, but real life stress

1:18:36 like work stress and relational stress, et cetera

1:18:40 is by suppressing the activation

1:18:43 of the so-called sympathetic nervous system,

1:18:46 meaning the alertness or stress system.

1:18:49 That involves buffering

1:18:51 or trying to resist the shiver response.

1:18:53 The shiver response is an autonomic response

1:18:56 designed to generate heat, presumably,

1:18:59 and actually that is what it does

1:19:01 in order to counter the cold.

1:19:03 So when you use cold exposure

1:19:05 and you're kind of muscling through it,

1:19:07 or you're learning to relax within it

1:19:09 as a form of stress inoculation,

1:19:11 that's great and works quite well for that purpose.

1:19:14 And there's a reason why cold exposure is used

1:19:16 in a variety of forms of military stress inoculation,

1:19:20 most famous of which of course is the Navy seal buds,

1:19:23 a strep test really,

1:19:26 which is screening procedure for becoming a seal

1:19:27 involves a lot of exposure to cold water.

1:19:31 However, if you're interested in using cold exposure

1:19:35 for fat loss and thermogenesis,

1:19:37 you want to do the exact opposite thing.

1:19:40 There was a paper published in nature two years ago

1:19:43 which showed that cold induced shiver,

1:19:47 the actual physical shiver activates the release of

1:19:52 a chemical in the body from muscle called succinate

1:19:56 S-U-C-C-I-N-A-T-E.

1:19:59 Succinate travel in the bloodstream and then goes

1:20:02 and activates a particular category of fat

1:20:05 not the typical kind pink or white fat

1:20:08 that we think of is like blubber in humans.

1:20:10 That the stuff that people will seem to

1:20:11 generally want less of,

1:20:13 except for those genetic freaks that seem to have none of it

1:20:16 depending what they consume.

1:20:18 Congratulations.

1:20:21 Brown fat is called Brown fat

1:20:23 because it's actually dark under the microscope.

1:20:25 It's rich with mitochondria and it exists mostly

1:20:29 between the scapulae and in the upper neck.

1:20:31 And it generates thermogenesis and heat in the body.

1:20:35 It's rich with a certain category of agile anergic receptor,

1:20:40 in insanely epinephrin binds to adrenergic receptors.

1:20:46 These Brown fat cells increase metabolism,

1:20:50 it's called Brown fat thermogenesis

1:20:52 and cause fat burning, burning of other kinds of fat,

1:20:56 the pink and white fat.

1:20:57 So what does this all mean?

1:20:58 This means if you want to use the ice bath

1:21:01 in order to increase metabolism, shiver away.

1:21:04 If you want to use the ice bath or cold shower

1:21:06 in order to stress inoculate, resist the shiver

1:21:10 and learn to stay calm or "muscle through it".

1:21:14 I mean, I don't know that anyone's ever really talked

1:21:15 about this publicly because I think the data are so new.

1:21:19 And I think that people assume that the ice bath

1:21:22 or cold exposure is just one thing.

1:21:24 Here I've talked about it three ways

1:21:26 to shift your circadian rhythm depending on whether or not

1:21:28 you're doing it early in the day

1:21:30 while your temperature is still rising or at its peak

1:21:34 or after that peak, in order to extend the perception

1:21:38 of your day as continuing and make you want to go

1:21:41 to sleep later and wake up later.

1:21:45 Now, and then the third way of course is to either

1:21:48 activate brown fat thermogenesis and increase metabolism.

1:21:51 I suppose the fourth way would be to

1:21:55 increase stress tolerance or stress threshold, okay?

1:21:58 But remember, temperature is the effector

1:22:01 of circadian rhythms.

1:22:02 Light is the trigger.

1:22:05 The super charismatic nucleus is the master circadian clock

1:22:08 that mediates all these changes,

1:22:10 also influenced by non-photic influence

1:22:12 like exercise and feeding and things of that sort.

1:22:15 But temperature is the effector.

1:22:18 Now you can also shift your circadian rhythm with eating.

1:22:21 When you travel and you land in a new location

1:22:24 and your schedule is inverted 12 hours.

1:22:27 One way that we know you can shift your rhythm

1:22:29 more quickly is to get onto the local meal schedule.

1:22:32 Now that probably has to do with two effects.

1:22:34 One or changes in temperature inducer,

1:22:36 eating induced increases in body temperature.

1:22:39 Now you should understand why that would work

1:22:41 as well as eating has this anticipatory secretion

1:22:45 of beta, of hyper cretin orexin

1:22:47 that I talked about it earlier.

1:22:49 So, if this is getting a little too down in the weeds,

1:22:51 don't worry about it.

1:22:53 I will get more into this in episode four

1:22:55 of how to shift one's rhythm.

1:22:56 But I would love for people to understand that light

1:22:59 and temperature are the real heavy duty leavers

1:23:02 when it comes to moving your circadian rhythm

1:23:03 and sleep times and activity schedules

1:23:06 and exercise and feeding can help,

1:23:08 but really temperature and light,

1:23:10 with light being the primary one are the most important

1:23:13 when it comes to sleep and wakefulness.

1:23:16 Many people asked questions about food and neurotransmitters

1:23:20 and how those relate to sleep, wakefulness and mood,

1:23:23 which is essentially 25 hours of content for me to cover.

1:23:28 But I'm going to try and distill out the most common questions.

1:23:32 We've talked a lot about neuromodulators like dopamine,

1:23:34 acetylcholine and norepinephrine.

1:23:37 You may notice in those discussions that the precursors

1:23:40 to say serotonin is tryptophan.

1:23:42 Tryptophan actually comes from the diet.

1:23:44 It comes from the foods that we eat.

1:23:47 tyrosine is the precursor to dopamine.

1:23:51 It comes from the foods that we eat.

1:23:53 And then once we ingest them

1:23:56 those compounds are circulated to a variety

1:23:59 of different cells and tissues, but it is true that our food

1:24:03 and the particular foods we can influence,

1:24:06 things like neuromodulator levels to some extent,

1:24:09 it's not the only way, because there are also enzymes

1:24:12 and biochemical pathways that are going to regulate

1:24:14 how much tyrosine gets converted into dopamine

1:24:17 and there are elements of the dopaminergic neurons,

1:24:19 the dopamine neurons themselves that are electrical

1:24:22 that have influence on this as well.

1:24:24 But there are a couple fair assumptions that we can make.

1:24:28 First of all, nuts and meats in particular red meats,

1:24:32 tend to be rich in things like tyrosine, right?

1:24:36 That tells you right there,

1:24:37 that because tyrosine is the precursor of dopamine,

1:24:40 and dopamine is the precursor of norepinephrine,

1:24:42 and epinephrine that those foods tend to lend themselves

1:24:47 toward the production of dopamine

1:24:50 and epinephrin and the sorts of things

1:24:53 that are associated with wakefulness.

1:24:55 Now, of course, the volume of food that we eat

1:24:58 also impacts our wakefulness.

1:24:59 If we eat a lot of anything,

1:25:01 whether or not it's ribeye steaks, rice, or cardboard,

1:25:05 please don't eat cardboard,

1:25:06 your stomach if it's very distended it will

1:25:09 draw a lot of blood into your gut and you will divert blood

1:25:12 from other tissues and you'll become sleepy.

1:25:14 So it's not just about food content,

1:25:16 it's also about food volume, all right?

1:25:18 Fasting states generally are associated with more alertness,

1:25:22 epinephrin so forth and fed states are generally associated

1:25:28 with more quiescence and relaxation, serotonin,

1:25:31 and the kind of things that lend themselves more towards

1:25:34 sleep and less toward alertness.

1:25:37 Foods that are rich in tryptophan tend to be things

1:25:39 like white meat, turkey, also complex carbohydrates.

1:25:43 So if you like you can start experimenting

1:25:46 depending on what foods you eat.

1:25:48 You can start experimenting with carbohydrate rich meals

1:25:53 for accessing sleep and more depth of sleep.

1:25:57 This is actually something I personally do.

1:25:59 I tend to eat pretty low carbs during the day.

1:26:02 I actually fast for until about noon.

1:26:03 Not because I have to work to do that,

1:26:05 but because I'd rather just drink caffeine

1:26:07 and water during that time.

1:26:08 And then sometime around noon

1:26:10 I can't take it anymore and I'm hungry.

1:26:12 And I eat and I try and eat low carb-ish

1:26:14 unless I've worked out extremely hard

1:26:16 in the previous two hours, which I rarely do,

1:26:19 although I do it sometimes.

1:26:21 And that meal is then designed to prolong my period

1:26:25 of wakefulness into the late afternoon.

1:26:27 And then sometime around dinner time

1:26:29 which for me is around 6:37 PM, 8:00 PM.

1:26:31 Sometimes as late as 9:00 PM, I tend to eat things

1:26:34 like white meat, fish, pastas, rice, that kind of thing.

1:26:39 My favorite food of all

1:26:41 for accessing tryptophan is actually a starch.

1:26:43 It's actually a vegetable.

1:26:44 And it's the croissant, which is my favorite vegetable.

1:26:47 I don't eat those all the time, but I love them

1:26:50 and they seem to increase dopamine as well.

1:26:53 I've never actually done the mass spectrometry

1:26:55 on a croissant, but they definitely increase tryptophan

1:26:57 and relaxation for me.

1:27:00 In all seriousness, low carbohydrate/fasted/ketogenic diets

1:27:05 tend to lend themselves toward wakefulness

1:27:07 by way of increasing epinephrin, norepinephrine, adrenaline

1:27:11 dopamine, and things of that sort.

1:27:14 Carbohydrate rich meals.

1:27:16 And I suppose we talked about meals as opposed to diet

1:27:19 tend to lend themselves more toward tryptophan, serotonin

1:27:23 and more lethargic states.

1:27:26 There is very limited evidence that I am aware of

1:27:29 that carbohydrates should be eaten at one time a day

1:27:32 as it relates to metabolism, et cetera.

1:27:35 I'm sure that will open up a certain amount of debate.

1:27:39 If you work out very hard

1:27:40 and you deplete glycogen, then this all changes.

1:27:43 So some people are working out very hard

1:27:44 in depleting glycogen and other people are not.

1:27:46 That gets way outside the context

1:27:48 of this particular podcast, but yes indeed different foods

1:27:51 can bias different neuromodulators

1:27:54 and thereby can modulate awaking

1:27:57 or our feelings of lethargy and sleepiness.

1:28:02 There are a couple effects of food that are independent

1:28:06 or I should say a couple of facts of eating,

1:28:07 'cause the food won't do it when it's sitting

1:28:09 across the table, but of eating that are powerful

1:28:13 for modulating circadian, rhythm, wakefulness, et cetera.

1:28:16 And that's because every time we eat

1:28:18 we get eating induced thermogenesis

1:28:20 regardless of what we eat.

1:28:21 Now that eating induced thermogenesis

1:28:24 and increase in metabolism,

1:28:25 which is an increase in temperature really,

1:28:28 is probably greatest for amino acid rich foods like meats,

1:28:34 but also other types of foods.

1:28:37 It's a minimal increase in body temperature

1:28:39 compared to say cold exposure or exercise.

1:28:42 Now, whether or not it's a quarter of a degree

1:28:44 or half a degree or a degree,

1:28:46 it really depends on the individual.

1:28:48 And of course there are blood sugar effects.

1:28:50 There are things like whether or not

1:28:53 you are type one or type two diabetic,

1:28:55 whether or not you're insulin resistant,

1:28:56 whether or not like there's a kid who

1:28:59 interns on the podcast here, who's 17 years old

1:29:03 and I'm convinced that he can eat anything

1:29:05 and he just seems to like burn it up

1:29:08 and he's growing it every time.

1:29:09 Actually the other day, he walked into the other room

1:29:11 and two days later, he walked out of the same room.

1:29:14 He came out in between of course,

1:29:15 but and I was like, you're grow?

1:29:18 And he was like, you know, but he's at that stage where

1:29:20 he's just growing.

1:29:21 Food is going to affect a teenager very differently

1:29:23 than it's going to affect a full-grown person.

1:29:26 So, in general, starchy carbohydrates, white meat,

1:29:31 such as turkey, some fish increased tryptophan,

1:29:33 therefore serotonin, therefore

1:29:36 more lethargic states more calm.

1:29:39 Meat, nuts and there are probably some plant-based foods

1:29:42 that I'm not aware of and I apologize,

1:29:44 I should read up on this that also are high in tyrosine

1:29:48 that can increase things like dopamine,

1:29:50 norepinephrine, epinephrin alertness.

1:29:53 So you can vary these however you like.

1:29:56 Most people I think are eating a variety of these things

1:29:58 in a given meals.

1:30:00 And there are other parameters of nutrition

1:30:02 that are important too.

1:30:03 Volume of food for the reasons that I mentioned before,

1:30:05 the volume of food in the gut, less food in the gut

1:30:09 whether or not it's empty or a small amount of food

1:30:10 which tend to correlate with wakefulness.

1:30:14 Large volumes of food of any kind will tend to correlate

1:30:18 and drive the calming response

1:30:21 and that's by way of this nerve pathway called the vegas.

1:30:23 We actually have sensory fibers in the gut that communicate

1:30:25 to a little protrusion of neurons

1:30:27 that sit right next to the juggler called the nodose ganglia

1:30:30 N-O-D-O-S-E unlike Costello,

1:30:34 it's no dose right now he's all dose.

1:30:36 Nodose actually means having many protrusions

1:30:39 and it's like kind of a lumpy collection of neurons.

1:30:42 A ganglia is just a collection of neurons.

1:30:43 And then it goes into the brain stem and then forward

1:30:47 in the brain to the areas of the brain they're involved

1:30:49 in production of various neuromodulators.

1:30:53 So what we eat and the volume of food

1:30:57 are both signaling to the brain.

1:30:59 It's not just one or the other.

1:31:01 And then there's also this eating induced thermogenesis.

1:31:04 And now, you know, from the discussion about temperature

1:31:06 that if you're eating early in the day

1:31:08 you're tending to shift your rhythm earlier.

1:31:10 So that you'll want to wake up earlier the next day

1:31:13 if you're eating very late in the day,

1:31:15 even if you can fall asleep after that,

1:31:17 there's a tendency for you to want to sleep later

1:31:19 the next day.

1:31:20 Now this of course is all going to be constrained by

1:31:23 when your kids need to eat,

1:31:24 and when your spouse needs to eat,

1:31:25 and when your friends need to eat,

1:31:26 or if you live alone or what other things you're doing,

1:31:28 if you're like me and you kind of don't eat until noon

1:31:31 then eat sometime around noon.

1:31:32 And then I'm terrible about meals.

1:31:33 I just start eating the ingredients

1:31:35 while I'm supposed to be cooking

1:31:36 and then eventually they're all gone

1:31:37 and I guess that's a meal.

1:31:40 It varies.

1:31:41 Some people are neurotically attached

1:31:43 to a particular meal schedule.

1:31:45 Some people are not.

1:31:46 I take my light exposure schedule far more seriously

1:31:49 than I take my meal schedule.

1:31:50 Although in general, try and eat healthy foods

1:31:53 for the most part croissants included.

1:31:56 I was asked several times whether or not

1:31:58 men and women or males and females

1:32:00 differ in terms of these neurotransmitter phenotypes

1:32:03 and the rhythms of sleep and temperature,

1:32:08 or we could probably devote a whole month

1:32:09 and we probably will devote an entire month

1:32:11 to what are called sex differences

1:32:13 because those tend to be related to things

1:32:14 we absolutely know like XX, or XY chromosomes

1:32:18 or XYY in some cases are double X chromosomes

1:32:21 as opposed to gender, sex and karyotype as we call it

1:32:24 genetic makeup is crystal clear.

1:32:28 There are things that correlate with one or the other

1:32:32 but it's complicated

1:32:33 and it's not something that's been explored in

1:32:36 what I think is enough detail.

1:32:38 Actually recently, I guess it was about five years ago,

1:32:42 the national institutes of health made it a mandate

1:32:44 that all studies use sex as a biological variable,

1:32:48 and actually explore both sexes of mice,

1:32:51 both sexes of humans when doing any kind of study

1:32:53 because there was a bias towards only using male animals

1:32:56 or male subjects prior to that time.

1:32:58 So a lot of data now coming out

1:33:00 revealing important sex differences

1:33:02 that I think are going to have powerful impact

1:33:05 on health practices, et cetera.

1:33:06 Response to drugs,

1:33:07 response to just different sleep schedules, et cetera.

1:33:10 Perhaps the most salient and obvious one

1:33:13 is that during pregnancy females experience a whole range

1:33:18 of endocrine and neuro effects

1:33:21 and we definitely will devote a month to pregnancy

1:33:23 and childbirth and child rearing.

1:33:26 And for that, I'd really like to bring in some experts.

1:33:29 I've got terrific colleagues at Stanford and elsewhere

1:33:31 that work on these things,

1:33:32 so that we can go into those in more depth.

1:33:33 So I'm not blowing off those questions.

1:33:35 I'm just, I'm kind of pushing them down the road

1:33:37 a little bit where I can give you a more thorough answer.

1:33:42 So as we finish up, I just want to offer you

1:33:45 the opportunity to do an experiment.

1:33:48 We've talked about a lot of variables

1:33:49 that can impact sleep and wakefulness.

1:33:51 And in keeping with the theme of the podcast

1:33:53 we are going to continue to talk about sleep and wakefulness

1:33:57 and tools for those, and the science behind those tools

1:34:00 as we go forward.

1:34:01 But there are really just four simple parameters

1:34:05 that you have control over,

1:34:07 that you can immediately start to record

1:34:11 and take note of just to see how you're doing

1:34:14 with these things.

1:34:15 With no judgment or perhaps no change

1:34:18 to what you're actually doing.

1:34:20 It might be interesting, just a suggestion to write down

1:34:24 for each day when you went outside to get sunlight

1:34:29 and when you did that, relative to waking.

1:34:31 So you would write down,

1:34:31 like the way I do this in my calendar is I'll

1:34:33 write down that I don't get exact about it.

1:34:36 I might say, I woke up at 6:15 and then I,

1:34:40 as I'll put a W 6:15, and then SL for sunlight

1:34:45 and you'll sometimes get outside right away.

1:34:46 Other times I'm less good at that.

1:34:47 And I'll go out around, let's say seven

1:34:51 and for how long, I don't maybe like 10, 15 minutes or so.

1:34:55 And then I'll put a little check

1:34:56 at the times that I eat my so-called meals.

1:34:59 Although, as I mentioned, sometimes my meals are

1:35:01 a bunch of small checks that just kind of extend

1:35:03 through the late hours of the day.

1:35:05 Yours might be more confined to certain times.

1:35:09 And then you might just take note of when you exercised,

1:35:14 just put down an E for when you exercise.

1:35:16 Weight training or aerobic exercise.

1:35:19 And you might note when you might've felt chilled or cold

1:35:23 if you do, or you might've felt particularly hot,

1:35:25 or if you woke up in the middle of night,

1:35:26 when you felt particularly hot.

1:35:28 And then the last thing you might want to do

1:35:29 is just write down

1:35:31 if and when you did a non sleep deep rest protocol,

1:35:33 an STR protocol, that could be meditation,

1:35:35 that could be yoga nidra, that could be hypnosis.

1:35:38 Anything that you're using to deliberately

1:35:42 teach your nervous system, how to go from more alertness

1:35:45 to more calmness in the waking state,

1:35:48 even if it's waking up in the middle of the night

1:35:49 and doing an SDR protocol or in the afternoon,

1:35:52 or first thing in the morning to recover some sleep

1:35:54 and ability to perform DPOs that you might've lost

1:35:57 from a minimal or poor night's sleep.

1:35:59 So you're going to rite down when you woke up,

1:36:01 when you viewed sunlight, that might be in the morning

1:36:04 and the evening, or just the morning, hopefully

1:36:06 it's the morning and the evening, when you exercised,

1:36:08 when you eat your meals and using a simple

1:36:11 record keeping scheme like W for waking, SL for sunlight

1:36:16 maybe you come up with a system where it's a check

1:36:18 or an X or something for exercise.

1:36:19 This is not designed to make you neurotically attached

1:36:22 to tracking all your behaviors and everything you do.

1:36:28 I for instance, don't track what I eat.

1:36:30 In particular, I kind of know what works for me

1:36:32 and I'd just try and stay within that range.

1:36:35 But by doing this you can start to reveal

1:36:38 some really interesting patterns.

1:36:39 Patterns that no answer that I could provide you about

1:36:43 any existing tool or protocol could counter.

1:36:48 It's really about taking the patterns of behaviors,

1:36:51 of waking, and light viewing, and eating,

1:36:53 and exercise and superimposing that on

1:36:58 what you're learning

1:36:58 in this podcast and elsewhere of course

1:37:01 and what you already know and trying to see where

1:37:03 certain problem or problems or pain points might be arising.

1:37:07 Maybe you're eating really late in the day

1:37:08 and you're waking up

1:37:09 in the middle of the night, really warm.

1:37:10 Well, now you would say, "Well, that could be due to

1:37:13 kind of an increase in temperature that is extending my day

1:37:17 or maybe you start to find that using cold exposure

1:37:21 early in the day is great for you,

1:37:22 but using it late, if it's too late in the day,

1:37:25 that's not great.

1:37:25 Or if you're into the sauna or it's even

1:37:29 like some people, including myself, if I take a hot shower

1:37:31 or sit in a hot tub or a sauna late at night,

1:37:34 well then I get a compensatory decrease in body temperature

1:37:37 and I sleep great provided I hydrate well enough,

1:37:40 'cause that can be kind of a dehydrating thing to sit

1:37:42 in hot, hot conditions.

1:37:44 But if I do the sauna early in the day,

1:37:46 unless I exercise immediately afterward

1:37:49 then I tend to get the temperature drop, which makes sense

1:37:52 because when you get in the sauna, you're get vasodilation.

1:37:55 You throw off a lot of heat and then you

1:37:56 generally get a compensatory drop in temperature.

1:37:58 If you do that early in the day, that's right

1:38:00 about the time that temperature

1:38:02 is trying to entrain the circadian clocks of your body.

1:38:04 That's what happens to me.

1:38:06 Other people, it might be slightly different

1:38:08 and some people have more resilient systems than others.

1:38:12 So I just encourage you to start becoming scientists

1:38:15 of your own physiology of your own brain and body

1:38:19 and seeing how the various tools that you may

1:38:21 or may not be using are effecting your patterns of sleep,

1:38:25 your patterns of attention and wakefulness.

1:38:27 It's vitally important that if you do this,

1:38:30 that you know that it's not about trying to get

1:38:32 onto an extremely rigid schedule,

1:38:35 it's really about trying to identify variables

1:38:38 that are most powerful for you, and that push you

1:38:41 in the direction that you want to go.

1:38:42 And changing the variables that are pushing your body

1:38:45 and your mind in the directions that you don't want to go.

1:38:47 Self experimentation is something that should be done

1:38:50 slowly, carefully, you don't want to be reckless about this.

1:38:54 And this is where I would say manipulating one

1:38:57 or two variables at a time is really going to be best

1:38:59 as opposed to changing of a dozen things all at once

1:39:02 to really identify what it is that's most powerful for you.

1:39:06 As always, thank you so much for your questions.

1:39:09 We are going to continue to answer questions.

1:39:12 I certainly didn't get to all of them

1:39:13 but we tried to get to most all of the ones

1:39:15 that were frequently asked.

1:39:17 Episode four of the podcast, I'm going to get into,

1:39:20 shift work, jet lag and age dependent changes

1:39:24 in sleeping and wakefulness and cognition.

1:39:28 So for those of you with kids,

1:39:30 for those of you that are kids

1:39:32 for those of you with older relatives or who might be older

1:39:36 meaning probably when you start to get into

1:39:39 late '60, '70 and '80 is when there's some marked

1:39:42 biological shifts in temperature regulation

1:39:44 and things that relate to sleep.

1:39:47 And for those of you that travel,

1:39:49 we're going to talk about jet lag.

1:39:50 The shift work discussion might seem only relevant

1:39:53 to those that work nights, but actually that's not the case.

1:39:56 Most people because of the way they're interacting

1:39:58 with devices are actually in a form of shift work now,

1:40:03 where the days are certainly not nine to five,

1:40:05 the so-called banker's hours,

1:40:06 and then the lights are out at nine

1:40:08 and they're asleep until 5:00 AM.

1:40:10 Some people have that schedule, most people do not.

1:40:12 So episode four, we will go deeply into shift work, jet lag

1:40:17 age dependent changes in sleep alertness and cognition

1:40:20 and I will touch back on a few of your questions

1:40:22 but don't think that

1:40:23 if your question wasn't answered during these office hours

1:40:25 that we won't get to it, I absolutely will at some point.

1:40:30 In addition to that, several of you

1:40:32 have graciously asked how you can help support the podcast.

1:40:35 And we very much appreciate that.

1:40:37 You can support the podcast by liking it on YouTube,

1:40:41 by subscribing on YouTube,

1:40:43 by recommending the YouTube videos to others,

1:40:46 as well as subscribing and downloading the podcast on Apple

1:40:50 where you can also leave a review and on Spotify,

1:40:53 we're all three, if you like.

1:40:55 you can also help us by supporting our sponsors.

1:40:58 So check out some of the sponsor links that were described

1:41:00 at the beginning of the episode.

1:41:02 And in general, recommending the podcast

1:41:04 to people that you know and that you think would benefit

1:41:06 from the information would be terrific.

1:41:08 As always I will be continuing to post on Instagram.

1:41:12 You can expect another podcast episode out next Monday

1:41:15 about the topics that we've been discussing this month

1:41:17 and above all, [upbeat music]

1:41:19 thank you for your interest in science.