Essentials: How to Defeat Jet Lag, Shift Work & Sleeplessness

00:00:00.000 | Welcome to Huberman Lab Essentials,

00:00:02.320 | where we revisit past episodes

00:00:04.380 | for the most potent and actionable science-based tools

00:00:07.560 | for mental health, physical health, and performance.

00:00:10.340 | I'm Andrew Huberman,

00:00:13.000 | and I'm a professor of neurobiology and ophthalmology

00:00:16.120 | at Stanford School of Medicine.

00:00:17.900 | Today's podcast episode is about jet lag, shift work,

00:00:22.360 | and we are going to discuss protocols

00:00:24.560 | that are backed by science

00:00:26.260 | that can support particular tools that you can use

00:00:29.440 | to combat things like jet lag,

00:00:31.680 | offset some of the negative effects of shift work,

00:00:34.080 | and make life easier for the new parent,

00:00:37.160 | as well as for the newborn child, the adolescent,

00:00:40.740 | anyone that wants to sleep better,

00:00:42.640 | feel better when they're awake, et cetera.

00:00:45.320 | Let's just take a step back for a moment

00:00:47.700 | and remind everybody what we're talking about.

00:00:50.240 | The circadian rhythm is a 24-hour rhythm

00:00:53.560 | in all sorts of functions.

00:00:56.000 | The most prominent one is a rhythm

00:00:58.460 | in our feelings of wakefulness and sleepiness.

00:01:01.680 | You also have a rhythm in sleepiness and wakefulness

00:01:04.920 | that correlates with that.

00:01:05.860 | We tend to be sleepy as our temperature is falling,

00:01:09.320 | getting lower, and we tend to be more awake or waking

00:01:14.320 | when our temperature is increasing.

00:01:16.840 | We have a clock over the roof of our mouth,

00:01:19.820 | a group of neurons called the suprachiasmatic nucleus.

00:01:23.000 | That clock generates a 24-hour rhythm,

00:01:25.840 | and that clock is entrained,

00:01:27.600 | meaning it is matched to the external light-dark cycle,

00:01:31.760 | which is, no surprise, 24 hours.

00:01:34.960 | Spinning the earth takes 24 hours.

00:01:37.360 | So our cells, our organs, our wakefulness, our temperature,

00:01:42.360 | but also our metabolism, our immune system, our mood,

00:01:48.540 | all of that is tethered to the outside light-dark cycle.

00:01:52.420 | And if we are living our life in a perfect way

00:01:55.860 | where we wake up in the morning

00:01:58.100 | and we view sunlight as it crosses the horizon,

00:02:01.460 | and then by evening we catch a little sunlight,

00:02:04.180 | and then at night we're in complete darkness,

00:02:07.820 | we will be more or less perfectly matched

00:02:10.060 | to the external or ambient light-dark cycle.

00:02:12.680 | Very few of us do that

00:02:15.620 | because of these things that we call artificial lights

00:02:18.580 | and this other thing that we call life demands.

00:02:21.920 | So today we're going to talk about

00:02:24.020 | when we get pulled away from that rhythm.

00:02:26.320 | So what is the perfect day?

00:02:28.500 | What does that look like

00:02:29.560 | from a circadian sleep wakefulness standpoint?

00:02:32.500 | You basically want to get as much light, ideally sunlight,

00:02:36.600 | but as much light into your eyes

00:02:39.020 | during the period of each 24-hour cycle

00:02:41.280 | when you want to be awake, when you want to be alert.

00:02:44.540 | And you want to get as little light into your eyes

00:02:48.500 | at the times of that 24-hour cycle

00:02:50.240 | when you want to be asleep or drowsy and falling asleep.

00:02:53.740 | How much is enough?

00:02:54.920 | Well, a good number to shoot for as a rule of thumb

00:02:58.340 | is to try and get exposure to at least 100,000 lux

00:03:02.740 | before 9 a.m., 10 a.m. maybe, but before 9 a.m.,

00:03:07.740 | assuming you're waking up sometime between 5 and 8 a.m.

00:03:12.820 | The mechanism of circadian clock setting

00:03:14.820 | involves these neurons in your eye

00:03:17.280 | that send electrical signals

00:03:18.740 | to this clock above the roof of your mouth.

00:03:21.160 | And that system sums, meaning it adds photons.

00:03:25.020 | It's a very slow system.

00:03:26.860 | So here we're talking about trying to get

00:03:28.060 | that at least 100,000 photons, but not all at once.

00:03:30.820 | So what do you do?

00:03:31.660 | You go outside.

00:03:32.480 | Going outside, even on a cloudy day,

00:03:34.880 | could be 7,000, 10,000 lux.

00:03:36.980 | It's really remarkable how bright it is,

00:03:39.540 | meaning how much photon energy is coming through.

00:03:41.460 | So try and get 100,000 lux before that 9 a.m.

00:03:45.340 | Now, if you can't do that

00:03:46.440 | because you live in an area of the world

00:03:48.300 | where it's just not bright enough.

00:03:50.880 | Some people have sent me pictures from Northern England.

00:03:54.340 | It's just not bright enough in winter.

00:03:56.460 | Then, sure, you can resort to using artificial lights

00:04:00.340 | in order to get enough photons.

00:04:02.860 | And I'm putting out this 100,000 lux number as a target

00:04:06.300 | to get each day before 9 a.m.

00:04:08.380 | You can, in theory, get it all from artificial lights,

00:04:10.660 | but there are some special qualities about sunlight

00:04:12.740 | that make sunlight the better stimulus.

00:04:15.020 | Then I've recommended, based on scientific literature,

00:04:18.660 | that you look at sunlight

00:04:21.220 | sometime around the time when the sun is setting.

00:04:23.500 | And the reason for that, of course,

00:04:24.820 | is because it adjusts down the sensitivity of your eyes,

00:04:28.740 | because here's the diabolical thing.

00:04:31.260 | While we need a lot of photon energy early in the day

00:04:34.420 | to wake up our system and set our circadian clock

00:04:36.580 | and prepare us for a good night's sleep

00:04:38.180 | 14 to 16 hours later,

00:04:40.220 | it takes very little photon energy

00:04:42.580 | to reset and shift our clock after 8 p.m.

00:04:46.700 | And that's why you want to, as much as you safely can,

00:04:49.500 | avoid bright light and even not so bright light

00:04:53.700 | between the hours of 10 or 11 p.m. and 4 a.m.

00:04:56.660 | So let's talk about shifting clocks,

00:04:58.140 | because for the jet lag person,

00:05:00.060 | this ability to shift the clock

00:05:03.340 | with light temperature exercise and food

00:05:05.780 | is vitally important

00:05:07.340 | for getting onto the new local schedule.

00:05:10.540 | And there's so much out there about jet lag today.

00:05:12.540 | I'm going to dial it down to one very specific parameter

00:05:15.500 | that all of you can figure out

00:05:17.820 | without any technology or devices

00:05:20.560 | and can apply for when you travel for work or pleasure

00:05:25.560 | or anytime you're jet lagged.

00:05:27.380 | And I want to absolutely emphasize

00:05:29.980 | that you don't have to travel to get jet lagged.

00:05:32.380 | Many of you are jet lagged.

00:05:34.300 | You're jet lagged because you're looking at your phone

00:05:35.920 | in the middle of the night.

00:05:36.860 | You're jet lagged because you're waking up

00:05:38.020 | at different times of day.

00:05:38.900 | You're jet lagged because your exercise

00:05:41.380 | is on a chaotic regime.

00:05:44.660 | Some days at this time, some days at that time,

00:05:46.860 | but there are some simple things that you can do.

00:05:49.100 | So that's where we're headed.

00:05:50.080 | Let's talk about what jet lag is.

00:05:51.900 | There are quality peer-reviewed papers

00:05:54.980 | showing that jet lag will shorten your life.

00:05:58.020 | Jet lag is a serious thing.

00:05:59.700 | Now, here's what's interesting.

00:06:01.760 | Traveling westward on the globe

00:06:05.460 | is always easier than traveling eastward, okay?

00:06:10.460 | It's interesting because the effects of jet lag

00:06:16.100 | on longevity have shown that traveling east

00:06:20.660 | takes more years off your life than traveling west.

00:06:24.320 | Now, here's what's interesting.

00:06:27.060 | When we think about the effects of jet lag on longevity

00:06:30.540 | or this idea that it can shorten our lives,

00:06:34.760 | we have to ask ourselves why, why is that?

00:06:38.580 | And it turns out there's a pretty simple

00:06:40.160 | explanation for this.

00:06:42.320 | We've talked before about the autonomic nervous system,

00:06:44.520 | this set of neurons in our spinal cord and body and brain

00:06:47.720 | that regulate our wakefulness and our sleepiness.

00:06:50.160 | Turns out that human beings and probably most species

00:06:54.940 | are better able to activate and stay alert

00:06:58.600 | than they are to shut down their nervous system

00:07:01.600 | and go to sleep on demand.

00:07:03.000 | So if you really have to push

00:07:05.080 | and you really have to stay awake, you can do it.

00:07:06.820 | You can stay up later,

00:07:08.540 | but falling asleep earlier is harder.

00:07:11.240 | And that's why traveling east

00:07:12.840 | has a number of different features associated with it

00:07:16.040 | that because you're traveling east,

00:07:18.160 | you're trying to go to bed earlier.

00:07:20.680 | You know, as a Californian, if I go to New York city,

00:07:23.840 | I've got to get to bed three hours early

00:07:25.420 | and wake up three hours earlier,

00:07:26.640 | much harder than coming back to California

00:07:29.060 | and just staying up a few more hours.

00:07:31.040 | And this probably has roots in evolutionary adaptation

00:07:36.040 | where under conditions where we need to suddenly gather up

00:07:38.800 | and go or forage for food or fight

00:07:41.760 | or do any number of different things

00:07:44.120 | that we can push ourselves

00:07:45.320 | through the release of adrenaline and epinephrine

00:07:47.080 | to stay awake.

00:07:47.960 | Whereas being able to slow down and deliberately fall asleep

00:07:51.180 | is actually much harder to do.

00:07:53.160 | So there's an asymmetry to our autonomic nervous system

00:07:55.380 | that plays out in the asymmetry of jet lag.

00:07:59.740 | All right, well, let's think about travel and what happens.

00:08:03.100 | Let's say you're not going eastward or westward,

00:08:06.680 | but you're going north or south.

00:08:08.760 | So if you go from, for instance, Washington DC

00:08:11.280 | to Santiago, Chile, you're just going north and south.

00:08:15.240 | You're not really moving into a different time zone.

00:08:17.680 | You're not shifting.

00:08:18.680 | So you will experience travel fatigue.

00:08:21.880 | And it turns out that jet lag has two elements,

00:08:23.800 | travel fatigue and time zone jet lag.

00:08:27.840 | Time zone jet lag is simply the inability

00:08:32.540 | of local sunlight and local darkness

00:08:36.020 | to match to your internal rhythm,

00:08:38.500 | this endogenous rhythm that you have.

00:08:40.260 | So before we get too complicated

00:08:43.220 | and too down in the weeds about this,

00:08:45.700 | I want to just throw out a couple important things.

00:08:48.020 | First of all, some people suffer from jet lag a lot,

00:08:50.860 | other people, not so much.

00:08:52.900 | Most people experience worse jet lag as they get older.

00:08:57.140 | There are reasons for that because early in life,

00:08:59.780 | patterns of melatonin release are very stable and flat

00:09:03.640 | and very high actually in children.

00:09:05.720 | Then it becomes cyclic during puberty,

00:09:07.400 | meaning it comes on once every 24 hours

00:09:10.300 | and turns off once every 24 hours.

00:09:11.760 | And then as we get older, the cycles get more disrupted

00:09:15.040 | and we become more vulnerable to even small changes

00:09:17.880 | in schedule, et cetera, meal times, right?

00:09:21.140 | So jet lag gets worse as we age.

00:09:23.280 | I want to make changing your internal rhythm really easy

00:09:28.280 | or at least as easy and as simple

00:09:30.620 | as one could possibly make it, I believe.

00:09:32.660 | What I want to talk about is perhaps

00:09:34.900 | one of the most important things to know

00:09:36.700 | about your body and brain,

00:09:38.240 | which is called your temperature minimum.

00:09:40.260 | Your temperature minimum is the point in every 24-hour cycle

00:09:44.800 | when your temperature is lowest.

00:09:46.400 | Now, how do you measure that without a thermometer?

00:09:50.860 | It tends to fall 90 minutes to two hours

00:09:53.240 | before your average waking time.

00:09:55.420 | Temperature actually is the signal

00:09:57.600 | by which this clock above the roof of your mouth

00:10:00.560 | entrains or collectively pushes all the cells

00:10:04.080 | and tissues of our body to be on the same schedule.

00:10:07.400 | Temperature is the effector.

00:10:09.240 | And once you hear that, there should be an immediate,

00:10:12.280 | oh, of course, because how else would you get

00:10:14.520 | all these different diverse cell types

00:10:17.920 | to follow one pattern, right?

00:10:19.680 | A pancreatic cell does something very different

00:10:21.900 | than a spleen cell or a neuron, right?

00:10:26.640 | They're all doing different things at different rates.

00:10:29.000 | So the temperature signal can go out

00:10:30.560 | and then each one of those

00:10:31.400 | can interpret the temperature signal

00:10:32.760 | as one unified and consistent theme of their environment.

00:10:37.440 | Here's the deal.

00:10:38.400 | If you expose your eyes to bright light

00:10:43.380 | in the four hours after your temperature minimum,

00:10:48.960 | your circadian clock will shift

00:10:51.940 | so that you will tend to get up earlier

00:10:54.320 | and go to sleep earlier in the subsequent days, okay?

00:10:58.340 | It's what's called a phase advance,

00:11:00.420 | if you'd like to read up on this further.

00:11:02.340 | You advance your clock.

00:11:04.240 | However, if you view bright light

00:11:07.840 | in the four to six hours before your temperature minimum,

00:11:11.560 | you will tend to phase delay your clock.

00:11:13.960 | You will tend to wake up later and go to sleep later.

00:11:17.480 | I tend to wake up at about 6 a.m.,

00:11:20.160 | sometimes 6.30, sometimes 7.

00:11:21.920 | It depends a lot on what I was doing the night before

00:11:24.040 | as I'm guessing it does for you.

00:11:25.500 | But that means that my temperature minimum

00:11:28.480 | is probably somewhere right around 4.30 a.m.,

00:11:31.480 | which means that if I wake up at 4.30 a.m.

00:11:34.960 | and I were to view bright light at 4.35 a.m.,

00:11:39.240 | I'm going to advance my clock.

00:11:41.700 | I'm going to want to go to bed earlier the subsequent night

00:11:45.400 | and wake up earlier the subsequent morning.

00:11:47.640 | And as I shift my wake-up time,

00:11:51.340 | my temperature minimum shifts too, right?

00:11:53.400 | If I were to view bright light in the four to six hours

00:11:56.120 | before 4.30 a.m., guess what?

00:11:59.240 | The next night I'm going to want to stay up later

00:12:01.600 | and I'm going to want to wake up later

00:12:03.640 | the subsequent morning.

00:12:04.760 | Your temperature minimum is a reference point,

00:12:08.000 | not a temperature reading.

00:12:10.120 | Again, if you want to measure your temperature minimum

00:12:12.700 | and figure out what it is, 98 point whatever,

00:12:14.900 | 96 point whatever, that's fine.

00:12:16.860 | You can do that, but that information won't help you.

00:12:19.420 | What you need to know is what time

00:12:21.140 | your body temperature is lowest

00:12:22.420 | and understand that in the four hours or so

00:12:25.060 | just after that time,

00:12:26.460 | viewing light will advance your clock

00:12:28.940 | to make you want to get up earlier.

00:12:30.740 | So now you can start to see and understand

00:12:33.180 | the logic of this system.

00:12:35.540 | You can now start to shift that temperature

00:12:37.460 | according to your travel needs.

00:12:39.700 | Here's one way in which you might do that.

00:12:42.140 | Let's say I am going to travel to Europe,

00:12:44.260 | which is nine hours ahead, typically, from California.

00:12:48.380 | I would want to determine my temperature minimum,

00:12:51.940 | which for me is about 4.30 a.m., maybe 5.00 a.m.,

00:12:55.040 | and I would want to start getting up at about 5.30 a.m.

00:13:00.040 | and getting some bright light exposure,

00:13:03.580 | presumably from artificial sources,

00:13:05.060 | because the sunlight isn't going to be out at that time,

00:13:08.660 | maybe even exercising as well,

00:13:10.100 | maybe even eating a meal at that time.

00:13:12.780 | You would want to start doing that

00:13:14.260 | two or three days before travel,

00:13:15.900 | because once you land in, or I land in Europe,

00:13:20.660 | chances are just viewing the sunrise or sunset in Europe

00:13:25.300 | is not going to allow me to shift my circadian clock.

00:13:28.060 | Some people say get sunlight in your eyes when you land,

00:13:30.220 | but that's not going to work,

00:13:32.380 | because one of two things is likely to happen.

00:13:35.660 | With a nine-hour shift like that,

00:13:37.080 | either I'm going to view sunlight

00:13:39.000 | at a time that corresponds to the circadian dead zone,

00:13:41.720 | the time in which my circadian clock can't be shifted,

00:13:45.140 | or I'm going to end up viewing sunlight

00:13:47.580 | at a time that corresponds to the four- to six-hour window

00:13:51.300 | before my temperature minimum.

00:13:55.300 | So it's going to shift me

00:13:56.140 | in exactly the opposite direction that I want to go.

00:13:59.820 | So it can be very, very challenging

00:14:02.460 | for people to adjust to jet lag.

00:14:04.580 | So you need to ask, am I traveling east,

00:14:06.860 | or am I traveling west?

00:14:07.760 | Am I trying to advance my clock or delay my clock?

00:14:10.580 | Remember, viewing light, exercise, and eating

00:14:14.420 | in the four to six hours before your temperature minimum

00:14:16.740 | will delay your clock.

00:14:17.760 | Eating, viewing sunlight, and exercising,

00:14:20.880 | you don't have to do all three,

00:14:21.920 | but some combination of those in the four to six hours

00:14:24.580 | after your temperature minimum will advance your clock.

00:14:27.700 | And this is a powerful mechanism

00:14:29.320 | by which you can shift your clock anywhere

00:14:31.320 | from one to three hours per day, which is remarkable.

00:14:35.780 | That means your temperature minimum is going to shift out

00:14:37.860 | as much as three hours,

00:14:40.060 | which can make it such that you can travel

00:14:42.500 | all the way to Europe.

00:14:44.440 | And as long as you've prepared for a day or so

00:14:47.580 | by doing what I described back home,

00:14:50.460 | and then doing it when you arrive,

00:14:52.800 | you can potentially accomplish the entire shift

00:14:55.060 | within anywhere from 24 to 36 hours.

00:14:58.500 | And so a lot of people are landing in Europe,

00:15:00.640 | getting sunlight in their eyes,

00:15:02.580 | and throwing their clock out of whack,

00:15:05.180 | or not shifting their clock at all.

00:15:07.460 | This brings me to the other thing that's highly recommended,

00:15:10.720 | and I've mentioned this before,

00:15:11.760 | but you want to eat on the local meal schedule.

00:15:14.140 | If it's in your practice to fast, fast, that's fine.

00:15:18.580 | But when you eat,

00:15:19.840 | you want to eat within the local schedule for alertness.

00:15:23.900 | Okay, I talked about traveling eastward,

00:15:27.060 | but we haven't talked about traveling westward.

00:15:29.340 | Let's say you're traveling from New York to California,

00:15:31.660 | or from Europe to California.

00:15:33.780 | The challenge there tends to be,

00:15:36.220 | how can you stay up late enough?

00:15:38.200 | Now, some people are able to do this,

00:15:40.260 | because as I mentioned earlier,

00:15:41.660 | the autonomic nervous system is asymmetrically wired,

00:15:44.780 | such that it's easier to stay up late,

00:15:47.020 | later than we would naturally want to,

00:15:49.180 | than it is to go to sleep earlier.

00:15:50.680 | So let's say you land, and it's 4 p.m.,

00:15:53.820 | and you're just dying.

00:15:55.380 | You're in California, you came from Europe,

00:15:56.980 | it's 4 p.m., and you really, really want to go to sleep.

00:16:00.500 | That's where the use of things like caffeine, exercise,

00:16:03.920 | and sunlight can shift you, right?

00:16:06.400 | If it's after your temperature peak,

00:16:08.720 | then viewing sunlight around 6 p.m. or 8 p.m.,

00:16:11.660 | or artificial light, if there isn't sunlight,

00:16:15.140 | will help shift you later, right?

00:16:17.500 | It's going to delay your clock,

00:16:19.100 | and you're going to be able to stay up later.

00:16:21.260 | The worst thing you can do is take a nap

00:16:24.120 | that was intended to last 20 minutes or an hour.

00:16:27.100 | I do this routinely, and then wake up four hours later,

00:16:30.060 | or you wake up, and it's midnight,

00:16:32.260 | and you can't fall back asleep.

00:16:33.460 | You really want to avoid doing that.

00:16:35.180 | So provided it's not excessive amounts,

00:16:38.220 | stimulants like caffeine and coffee or tea

00:16:40.100 | can really help you push past that afternoon barrier

00:16:43.300 | and get you to sleep more like on the local schedule,

00:16:47.420 | and eating on the local schedule as well.

00:16:50.700 | A number of people have asked

00:16:51.820 | about the use of melatonin to induce sleepiness.

00:16:55.000 | Melatonin is this hormone

00:16:56.260 | that's released from the pineal gland.

00:16:57.820 | Melatonin induces sleepiness.

00:17:00.220 | Melatonin during development is also responsible

00:17:04.180 | for timing the secretion of certain hormones

00:17:06.860 | that are vitally important for puberty.

00:17:09.780 | Does melatonin control the onset of puberty?

00:17:13.460 | Not directly, but indirectly.

00:17:16.060 | Melatonin inhibits something

00:17:17.900 | called gonadotropin-releasing hormone,

00:17:19.740 | which is a hormone that's released from your hypothalamus,

00:17:21.900 | also roughly above the roof of your mouth and your brain.

00:17:24.660 | Gonadotropin-releasing hormone is really interesting

00:17:26.500 | 'cause it stimulates the release of another hormone

00:17:28.900 | called luteinizing hormone,

00:17:30.360 | which in females causes estrogen

00:17:34.120 | to be released within the ovaries.

00:17:37.100 | It's involved in reproductive cycles,

00:17:38.820 | and in males stimulates testosterone

00:17:41.900 | from the sertoli cells of the testes.

00:17:44.960 | Melatonin is inhibitory to GNRH,

00:17:49.180 | gonadotropin-releasing hormone,

00:17:50.460 | and therefore is inhibitory to LH, luteinizing hormone,

00:17:53.180 | and therefore is inhibitory to testosterone and estrogen.

00:17:56.140 | There's just no two ways about it.

00:17:57.300 | So melatonin is used widely for inducing sleepiness

00:18:01.940 | when you want to fall asleep

00:18:03.100 | in the new location that you've arrived, right?

00:18:05.500 | You can't fall asleep.

00:18:06.340 | You take melatonin, it helps you fall asleep.

00:18:08.720 | It does not help you stay asleep.

00:18:11.140 | In addition to that,

00:18:12.740 | melatonin has been kind of touted

00:18:14.980 | as the best way to shift your circadian clock.

00:18:17.700 | I'm happy to go on record saying,

00:18:19.380 | "Look, if you need melatonin

00:18:20.220 | and you can work with a doctor

00:18:21.620 | or somebody who really understands circadian

00:18:23.300 | and sleep biology, go for it, if that's your thing."

00:18:26.160 | But I, as always on this podcast and elsewhere,

00:18:30.660 | I have a bias toward behavioral things

00:18:33.900 | that you can titrate and control,

00:18:35.200 | like exposure to light, exercise, temperature, et cetera,

00:18:38.100 | that have much bigger margins for safety

00:18:40.900 | and certainly don't have these other endocrine effects

00:18:42.900 | that we've been thinking about and talking about.

00:18:45.620 | So if you want to take melatonin in the afternoon

00:18:48.940 | in order to fall asleep or in the evening,

00:18:51.020 | be my guest, that's up to you.

00:18:53.080 | Again, you're responsible for your health, not me.

00:18:55.940 | But for many people,

00:18:57.860 | melatonin is not going to be the best solution.

00:19:00.500 | The best solution is going to be to use light

00:19:03.380 | and temperature and exercise

00:19:05.140 | on either side of the temperature minimum

00:19:07.420 | to shift your clock both before your trip

00:19:09.260 | and when you land in your new location

00:19:11.000 | and your clock starts to shift.

00:19:12.540 | Okay, so now you know my opinions about melatonin.

00:19:15.820 | Feel free to filter them through your own opinions

00:19:18.860 | and experiences with melatonin.

00:19:21.220 | And now you also understand what your temperature minimum is

00:19:24.780 | and how it represents an important landmark,

00:19:27.460 | either side of which you can use light temperature

00:19:30.860 | and exercise to shift your clock.

00:19:33.380 | Just to remind you a little bit about temperature,

00:19:35.000 | if you want to shift your clock,

00:19:36.960 | you can take a hot shower

00:19:38.060 | and then that will have a cooling effect

00:19:40.120 | after the hot shower.

00:19:41.480 | And if you were to get into a cold shower or an ice bath,

00:19:45.780 | if you have access to one,

00:19:47.160 | afterward, there's going to be a thermogenic effect

00:19:49.460 | of your body increasing temperature.

00:19:51.660 | So you can start to play these games

00:19:52.960 | with timing and hot and cold,

00:19:55.060 | with meals, whether or not you eat or you don't eat,

00:19:57.580 | and with light exposure,

00:19:58.780 | whether or not you view light or you don't view light.

00:20:01.260 | So now you can start to see why understanding

00:20:03.260 | the core mechanics of a system

00:20:05.320 | can really give you the most flexibility.

00:20:07.100 | And that really underscores the most important thing

00:20:08.980 | is that when you understand mechanism,

00:20:10.420 | it's not about being neurotically attached

00:20:13.140 | to a specific protocol, it's the opposite.

00:20:15.340 | It can give you great confidence and flexibility

00:20:18.020 | in being able to shift your body rhythms however you want.

00:20:20.100 | And when things get out of whack,

00:20:21.060 | you can tuck them right back into place.

00:20:23.240 | One thing that's common

00:20:25.060 | is that people need to do a quick trip.

00:20:27.060 | It's not always that you're going to go to,

00:20:28.820 | you know, on vacation for two weeks

00:20:30.180 | or, you know, work someplace else for weeks on end.

00:20:34.980 | If your trip is 48 hours or less,

00:20:38.300 | stay on your home schedule.

00:20:39.740 | 72, that's when you start running into trouble.

00:20:42.160 | The transit time is also important,

00:20:44.480 | but I would say if it's three days or less,

00:20:46.900 | stay on your home schedule as much as you can.

00:20:50.140 | So let's talk a little bit about a different form of jet lag

00:20:54.460 | that requires no planes, no trains, no automobiles,

00:20:58.240 | and that's shift work.

00:20:59.720 | Shift work is becoming increasingly common.

00:21:03.480 | Many of us are shift working even though we don't have to.

00:21:07.360 | We're doing work in the middle of the night.

00:21:09.220 | We are, you know, working on our computers at odd hours,

00:21:13.500 | sleeping during the day.

00:21:14.580 | Here's the deal with shift work.

00:21:16.260 | If there's one rule of thumb for shift work,

00:21:19.140 | it's that if at all possible,

00:21:21.960 | you want to stay on the same schedule for at least 14 days,

00:21:25.920 | including weekends.

00:21:27.740 | Now that should immediately cue the non-shift workers

00:21:31.020 | to the importance of not getting too far off track

00:21:33.720 | on the weekend, even if you're not a shift worker.

00:21:35.460 | So sleeping in on Sunday is not a good idea.

00:21:39.020 | The most important thing about shift work

00:21:40.760 | is to stay consistent with your schedule.

00:21:43.500 | If you're going to work a shift where,

00:21:46.180 | let's say you start at 4 p.m. and you end at 2 a.m.,

00:21:50.180 | excuse me, then there's some important questions that arise.

00:21:54.280 | For instance, should you see light during your shift?

00:21:58.700 | Well, this is a matter of personal choice,

00:22:02.020 | but ideally you want to view as much light as possible

00:22:04.700 | and as safely possible when you need to be alert.

00:22:07.660 | So that would mean from 4 p.m. to 2 a.m.

00:22:10.540 | And then you would want to sleep.

00:22:14.380 | So using light as a correlate of alertness

00:22:18.340 | and using darkness as a correlate of sleepiness,

00:22:21.340 | what this means is see as much light as you safely can

00:22:23.900 | during the phase of your day when you want to be awake.

00:22:27.300 | So let's say you go to sleep at,

00:22:30.260 | you get home after this 4 p.m. to 2 a.m. shift,

00:22:33.720 | you maybe eat something, you go to sleep,

00:22:36.620 | and you wake up and it's noon or 1 p.m.

00:22:41.620 | Should you get light in your eyes?

00:22:43.820 | You guessed it, you need to know your temperature minimum.

00:22:46.920 | You need to know whether or not

00:22:48.620 | your temperature is increasing or decreasing.

00:22:51.460 | And now we can make this whole thing even simpler

00:22:53.540 | and just say, if your temperature is decreasing,

00:22:57.380 | avoid light.

00:22:58.220 | If your temperature is increasing, get light.

00:23:02.260 | It's that simple.

00:23:05.420 | I'm going to pause there,

00:23:06.300 | and then I want to talk about kids and the elderly.

00:23:08.700 | In other words, how do we control sleep

00:23:12.300 | and circadian rhythms and wakefulness in babies,

00:23:15.440 | adolescents, teens, and aged folks?

00:23:19.220 | All right, as I mentioned earlier,

00:23:20.720 | melatonin is not cyclic, it's not cycling in babies.

00:23:25.540 | It's more phasic.

00:23:26.700 | It's being released at a kind of a constant level.

00:23:29.820 | And babies tend to be smaller than adults, they are.

00:23:32.760 | And so those concentrations of melatonin are very high.

00:23:35.580 | As a baby grows, those concentrations per unit volume

00:23:38.500 | are going to go down.

00:23:39.940 | Babies are not born with a typical sleep-wake cycle,

00:23:43.080 | and now all the parents are saying,

00:23:44.620 | "Tell me something I didn't know."

00:23:46.460 | Perhaps the most important thing,

00:23:49.580 | if you're having to map to a baby's schedule

00:23:52.820 | in order to make sure that they're getting changings

00:23:55.080 | and nursing, et cetera, at the appropriate times,

00:23:57.640 | is to try and maintain, if you can't sleep,

00:24:02.640 | or you can't sleep continuously,

00:24:05.140 | to try and maintain your autonomic nervous system

00:24:09.340 | in a place where you're not going into heightened states

00:24:12.620 | of alertness when you would ideally be sleeping.

00:24:16.380 | Now, I realize that this could be translated

00:24:19.200 | to try and stay calm while you're sleep-deprived,

00:24:21.180 | which is very hard for people to do.

00:24:23.300 | But this is where the non-sleep-deep rest protocols

00:24:26.260 | surface again, and can potentially be very beneficial

00:24:29.420 | for people to be able to recover, not necessarily sleep,

00:24:33.220 | but for them to maintain a certain amount

00:24:35.640 | of autonomic regulation.

00:24:37.260 | Last night, I woke up, I went to bed about 10.30.

00:24:40.220 | I woke up at three in the morning.

00:24:42.140 | I knew I wasn't feeling rested.

00:24:44.380 | I did a NSDR protocol.

00:24:47.220 | I fell back asleep.

00:24:48.300 | I woke up at 6.30.

00:24:49.500 | You need to teach your brain and your nervous system

00:24:52.420 | how to turn off your thoughts and go to sleep.

00:24:54.660 | And ideally, you do that without medication,

00:24:56.300 | unless there's a real need.

00:24:57.700 | You do that through these behavioral protocols.

00:24:59.340 | They work because they involve using the body

00:25:02.660 | to shift the mind, not trying to just turn off

00:25:04.560 | your thoughts in the middle of the night.

00:25:05.940 | Similar circumstances can arise if you're taking care

00:25:08.100 | of a very sick loved one, you're up all night.

00:25:10.700 | Try and stay calm using NSDR protocols.

00:25:13.300 | I know it's harder to do than to say,

00:25:16.480 | but those protocols are there, they're free.

00:25:18.780 | There's research to support them.

00:25:20.500 | Try and get sleep whenever you can,

00:25:22.500 | but also try to get morning sunlight

00:25:25.780 | and evening sunlight in your eyes if you can.

00:25:28.040 | And if you can't get that, use artificial light, okay?

00:25:31.780 | Once again, I've thrown a tremendous amount

00:25:33.580 | of information at you.

00:25:35.660 | I hope you will figure out your temperature minimum

00:25:38.220 | and start working with that to access

00:25:41.620 | the sleep and wakeful cycles that you want to access.

00:25:44.860 | I hope that you'll explore NSDR.

00:25:47.180 | You have now access to a lot of mechanism

00:25:50.200 | about sleep and wakefulness.

00:25:51.540 | I really believe that as we drill deeper and deeper

00:25:54.340 | into these mechanisms and you start hearing

00:25:56.560 | some of the same themes again and again,

00:25:58.700 | you're going to start to develop an intuition

00:26:01.220 | and an understanding of how these systems work in you

00:26:03.560 | and your particular life circumstances.

00:26:05.220 | So know your temperature minimum.

00:26:07.300 | Understand light in the early part of the day is valuable.

00:26:10.420 | Light when you want to be awake,

00:26:11.540 | provided it's not so bright, it's damaging.

00:26:13.200 | It's great for you whether or not it comes from screens

00:26:14.900 | or sunlight, but sunlight's better.

00:26:16.900 | Avoid light in the four to six hours

00:26:19.760 | before your temperature minimum,

00:26:21.120 | or else you're going to delay your clock

00:26:22.560 | unless you're traveling and that's what you want to do, okay?

00:26:25.420 | Use temperature, increase temperature to shift your clock.

00:26:28.340 | Decrease temperature to delay your clock.

00:26:30.620 | Thanks so much for your time and attention.

00:26:32.220 | I really appreciate it.

00:26:33.600 | See you next time on the Huberman Lab Podcast.

00:26:36.400 | And as always, thanks for your interest in science.

00:26:39.260 | [upbeat music]

00:26:41.840 | (upbeat music)

Essentials: How to Defeat Jet Lag, Shift Work & Sleeplessness

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