Essentials: Timing Light for Better Sleep, Energy & Mood

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

00:00:02.200 | where we revisit past episodes

00:00:04.040 | for the most potent and actionable science-based tools

00:00:07.220 | for mental health, physical health, and performance.

00:00:10.000 | I'm Andrew Huberman,

00:00:13.020 | and I'm a professor of neurobiology and ophthalmology

00:00:15.720 | at Stanford School of Medicine.

00:00:17.220 | Today, I have the pleasure of introducing Dr. Samer Hattar

00:00:21.120 | as my guest on the Huberman Lab podcast.

00:00:23.360 | And now, my conversation with Dr. Samer Hattar.

00:00:26.840 | Samer, thanks for sitting down with me.

00:00:30.140 | My pleasure.

00:00:30.620 | You are best known in scientific circles

00:00:32.840 | for your work on how light impacts mood,

00:00:36.000 | learning, feeding, hunger, sleep,

00:00:39.960 | and these sorts of topics.

00:00:41.200 | So maybe you could just wade us into

00:00:44.100 | what the relationship is between light

00:00:46.880 | and these things like mood and hunger, et cetera.

00:00:49.380 | Sure.

00:00:49.800 | So, I mean, you do appreciate the effect of light for vision.

00:00:54.400 | So when you wake up in a beautiful area,

00:00:57.800 | beautiful ocean, light is essential.

00:01:00.480 | The sunrise, the sunset.

00:01:02.240 | So that's your conscious perception of light.

00:01:05.180 | But light has a completely different aspect

00:01:08.320 | that is independent of conscious vision.

00:01:10.860 | And that's how it regulates

00:01:12.760 | many important functions in your body.

00:01:15.380 | I think the best that is well-studied and well-known

00:01:18.640 | is your circadian clock.

00:01:19.960 | And the word circadian comes from the word circa,

00:01:23.340 | which is approximate, and DNA is day.

00:01:25.500 | So it's an approximate day.

00:01:27.240 | Why is it an approximate day?

00:01:28.740 | Because if I put you or any other human being

00:01:31.820 | who have a normal circadian clock

00:01:33.500 | in a constant conditions,

00:01:35.360 | with no information about feeding time,

00:01:38.240 | about sleep time,

00:01:39.580 | about what time it is outside,

00:01:41.320 | you still have a daily rhythm,

00:01:43.420 | but it's not exactly 24 hours.

00:01:45.520 | So it will shift out of the solar day

00:01:48.400 | because it's not exactly 24 hours,

00:01:50.560 | and hence the name circadian.

00:01:51.680 | How does that rhythm show up

00:01:53.120 | in the tissues of our body?

00:01:54.520 | It shows up at every level that we know we studied.

00:01:57.560 | It shows up at the level of the cell.

00:01:59.540 | It shows up at the level of the tissue.

00:02:01.680 | and it shows up at your behavior.

00:02:03.200 | The most obvious for you is your sleep-wake cycle.

00:02:06.280 | You sleep and you're awake and sleep

00:02:09.040 | at the 24-hour rhythms.

00:02:10.500 | The period length of the sleep rhythm on average

00:02:13.260 | is 24.2 hours.

00:02:14.900 | So you'll be drifting 0.2 hours every day

00:02:17.680 | out of the solar day if you don't get the sunlight.

00:02:20.540 | So the sunlight adjusts that approximate day

00:02:24.640 | to an exact day.

00:02:25.580 | So now your behavior is adjusted

00:02:27.940 | to the light-dark environment or the solar day.

00:02:31.120 | It's part of the brain that is not consciously driven.

00:02:33.760 | So you actually do not know when it happens

00:02:36.460 | or when it doesn't happen.

00:02:37.440 | And that's what we'll get into

00:02:39.320 | when I tell you why light affects your mood

00:02:41.240 | and why sometimes people don't know

00:02:42.860 | how to deal with light to improve their mood,

00:02:44.900 | for example.

00:02:45.580 | What's the relevance?

00:02:46.700 | I mean, why should we care about that short difference?

00:02:48.660 | So let's do the math.

00:02:49.720 | If you shift out 0.2 hours a day,

00:02:51.940 | in five days, you're shifting out one hour.

00:02:53.860 | So you're literally one hour off

00:02:55.900 | in your social behavior in five days.

00:02:58.500 | In 10 days, you're two hours off.

00:03:00.560 | And if you're an organism that is living in the wild,

00:03:03.660 | shifting out of the right phase of the cycle,

00:03:06.460 | you could either miss food or you could become food.

00:03:08.740 | So it's really essential for survival.

00:03:11.320 | I think it's one of the strongest aspects

00:03:13.440 | of survival for animals to have the anticipation

00:03:17.420 | and the adjustment to the solar cycle.

00:03:20.560 | what is the machinery that allows that to happen?

00:03:24.560 | And how does that machinery work?

00:03:27.580 | Yeah.

00:03:28.020 | So we knew that in mammals, including us,

00:03:30.980 | we are mammals, humans,

00:03:32.080 | that the eyes are required for this function.

00:03:34.460 | So if humans are born without eyes

00:03:37.280 | or the optic nerves are damaged,

00:03:38.980 | humans are not able to adjust to the solar cycle.

00:03:42.780 | So we know that the eyes are required.

00:03:44.960 | In the human retinas,

00:03:46.060 | there are two types of photoreceptors.

00:03:48.060 | They are called rods and cones because of their shapes.

00:03:51.380 | And these rods and cones simply take the photon energy,

00:03:54.820 | which light is made of,

00:03:56.160 | and they change it in a way to an electrical signal

00:03:59.080 | that allow us to build the image of the environment

00:04:02.780 | in our cortices.

00:04:04.340 | However, people have found,

00:04:06.360 | including me with the work of David Burson

00:04:08.820 | and Ignacio Provencio,

00:04:09.900 | that there is a subset of ganglion cells.

00:04:13.020 | The ganglion cells are the cells that leave the retina,

00:04:16.240 | their axon, leave the retina,

00:04:17.800 | and project to the brain.

00:04:19.260 | So these were taught to only relay rod and cone information

00:04:23.100 | from the light environment to the brain.

00:04:24.840 | We found that a small subset of these ganglion cells

00:04:28.880 | are themselves photoreceptors

00:04:30.640 | that were completely missed in the retina.

00:04:33.520 | And these are the photoreceptors

00:04:35.240 | that relay light environment subconsciously

00:04:38.580 | to the areas in the brain

00:04:41.200 | that have and house the circadian clock

00:04:43.660 | or the circadian pacemaker,

00:04:45.200 | which adjusts all the clocks in our bodies

00:04:48.000 | to the central brain clock

00:04:49.540 | that allows them to entrain

00:04:51.280 | to the 24-hour light dark cycle.

00:04:53.660 | So these are cells that connect the eye of the brain

00:04:55.700 | that behave like photoreceptors, essentially.

00:04:57.720 | I think it's worth mentioning now

00:04:59.900 | that people who are pattern vision blind,

00:05:02.700 | so people who cannot see but have eyes,

00:05:05.480 | many of them still have these cells,

00:05:07.260 | these melanopsin intrinsically photosensitive cells,

00:05:10.480 | and can essentially match or entrain, as we say,

00:05:14.700 | onto the light-dark cycle.

00:05:16.460 | In fact, they possibly have no problems

00:05:18.460 | in circadian photoentrainment.

00:05:19.800 | They'll have enormous sleep-wake cycle.

00:05:22.080 | But they're totally blind.

00:05:22.920 | But they are totally image blind.

00:05:24.540 | And what's really interesting is that,

00:05:26.600 | and this story I heard from Chuck Seisler,

00:05:28.920 | so I'll give him credit,

00:05:29.820 | that some of these people who are image blind,

00:05:32.600 | usually they get dry eyes

00:05:34.580 | and they give them a lot of pain.

00:05:36.040 | And doctors used to think,

00:05:38.000 | oh, since they are image blind

00:05:39.660 | and they're getting dry eye,

00:05:40.920 | why don't you just remove their eyes?

00:05:42.500 | They're not using them anymore.

00:05:43.720 | And the minute they would remove their eyes,

00:05:46.060 | they start having cyclical sleep problems,

00:05:48.640 | indicating that now they are not in training

00:05:51.100 | to the light-dark cycle

00:05:52.360 | and are having cyclical jet lags

00:05:55.100 | when their clock shifts

00:05:56.300 | through the light-dark cycle.

00:05:58.280 | That's really interesting.

00:05:59.300 | And I hear from a number of blind people,

00:06:02.060 | a lot of them have issues with sleep,

00:06:04.160 | I think, in part because they don't realize

00:06:06.660 | that they too need to see light

00:06:08.280 | at particular times of day or night

00:06:09.860 | in order to match their schedule.

00:06:11.840 | Absolutely.

00:06:12.280 | What is the proper way to interact with light

00:06:15.600 | in the first part of the day?

00:06:18.180 | Honestly, I think the easiest thing is waking up.

00:06:20.780 | Get as much light as you can.

00:06:22.120 | Into your eyes.

00:06:22.840 | Yeah, it's really nice.

00:06:24.220 | Your system is primed.

00:06:25.640 | If you're entrained, it's primed to get light.

00:06:27.700 | The sun should be out.

00:06:28.860 | Even when it's cloudy,

00:06:30.040 | you're going to get enough intensity

00:06:31.560 | to help you adjust your cycle

00:06:33.520 | to the day-night cycle.

00:06:34.580 | These are general rules of thumb,

00:06:35.760 | but how long do you recommend people go outside?

00:06:38.020 | So if you do it daily,

00:06:38.960 | I would say 15 minutes.

00:06:40.340 | If you don't do it daily,

00:06:41.500 | you may want to increase it.

00:06:42.720 | You do it more, it doesn't hurt.

00:06:44.260 | And I'll tell you, if you're sensitive,

00:06:46.080 | you don't even have to go in the sun.

00:06:48.380 | You could be in the shade.

00:06:49.380 | There's going to be so many photons

00:06:51.420 | out there in the shade.

00:06:52.440 | It's going to be perfect.

00:06:53.880 | Okay, and if for some reason

00:06:55.840 | one finds themselves

00:06:56.820 | very far north

00:06:58.020 | and it's very, very dense cloud cover,

00:07:01.440 | how long and at what point

00:07:04.000 | should somebody consider

00:07:05.420 | using an artificial light source

00:07:07.440 | to mimic the sunlight?

00:07:08.840 | Yeah, honestly,

00:07:10.600 | this is where we don't have

00:07:12.080 | a lot of information still

00:07:13.440 | because this is where

00:07:15.440 | we're going to discuss this

00:07:16.480 | maybe in more detail

00:07:17.640 | that if you put humans

00:07:19.400 | in artificial conditions,

00:07:20.800 | the circadian system

00:07:22.560 | is very sensitive to light.

00:07:24.120 | But in reality,

00:07:26.280 | in the real environment,

00:07:28.020 | light also is affecting

00:07:29.600 | other aspects

00:07:30.580 | that are independent

00:07:31.860 | of the setting

00:07:32.980 | of the circadian pacemaker.

00:07:34.440 | Okay.

00:07:35.060 | And these,

00:07:35.640 | which we call

00:07:36.260 | the direct effect of light

00:07:37.500 | on mood, for example.

00:07:38.660 | so that is very hard

00:07:40.920 | to figure out

00:07:41.620 | what intensity

00:07:42.440 | you need to use.

00:07:43.260 | And we haven't done

00:07:44.160 | enough experiments

00:07:44.780 | because the system

00:07:45.420 | has been discovered

00:07:46.260 | just recently.

00:07:47.160 | But yeah,

00:07:48.220 | I mean,

00:07:48.500 | if you're honestly,

00:07:49.700 | if you're that far north

00:07:51.140 | and you're in the winter

00:07:52.080 | and you want to get,

00:07:52.880 | make sure you don't

00:07:53.760 | use these light boxes.

00:07:55.160 | I would suggest that

00:07:56.540 | personally.

00:07:57.340 | okay,

00:07:57.520 | so I think we've

00:07:58.480 | nailed down

00:07:59.640 | that first part of the day.

00:08:00.920 | Basically,

00:08:01.380 | it's get 10 to 30 minutes

00:08:02.640 | depending on how bright it is

00:08:03.900 | and try and do that

00:08:04.760 | as often as possible

00:08:06.440 | to give the system

00:08:07.220 | a regular...

00:08:07.700 | Daily is the best.

00:08:08.440 | This system

00:08:09.080 | is really about,

00:08:10.460 | and you'll see that

00:08:11.940 | even for the effect

00:08:12.960 | on depression,

00:08:13.460 | it's about multiple days.

00:08:14.980 | So you don't have to worry

00:08:16.660 | if you missed it one day,

00:08:17.940 | you know,

00:08:18.640 | stay longer if you want.

00:08:19.920 | But if you're in a hurry

00:08:21.560 | and you want to do other stuff,

00:08:22.860 | that's a great recommend.

00:08:24.100 | So you might want to compensate

00:08:25.560 | with some extra time

00:08:26.480 | if you missed a day

00:08:27.180 | or two.

00:08:27.520 | I've heard you say before,

00:08:28.600 | it's entirely possible

00:08:29.900 | to get severely jet-lagged

00:08:31.700 | without traveling.

00:08:32.480 | Absolutely.

00:08:33.060 | Simply by staying in,

00:08:34.620 | being on your phone too much,

00:08:35.720 | not getting the sunlight.

00:08:36.660 | And you saw this

00:08:37.500 | during the pandemic.

00:08:38.680 | A lot of people mentioned

00:08:40.020 | that their sleep-wake cycles

00:08:41.460 | suffered a lot

00:08:42.480 | because if you're not going out

00:08:45.620 | and if you're staying at home

00:08:47.160 | and you don't have big windows

00:08:48.620 | and you're waking late,

00:08:50.480 | waking up late,

00:08:51.480 | and then you're using

00:08:52.280 | very bright light

00:08:53.280 | till late at night,

00:08:54.240 | your body's going to shift.

00:08:55.440 | And now,

00:08:56.520 | your day is going to start

00:08:58.180 | instead of like really

00:08:59.340 | when the sun comes up,

00:09:00.360 | let's say at 6 o'clock

00:09:01.340 | in the morning,

00:09:01.880 | it's going to,

00:09:02.540 | your day is going to start

00:09:03.580 | at 11 o'clock in the morning.

00:09:04.740 | That's what your body's going to think

00:09:06.340 | is the beginning of the day.

00:09:07.700 | So then you're not going to be able

00:09:10.440 | to sleep at 10 o'clock at night

00:09:12.300 | because now that's really,

00:09:14.620 | for your body,

00:09:16.060 | it's completely different timing.

00:09:17.500 | There is this idea of chronotypes

00:09:19.320 | that we all each intrinsically

00:09:21.780 | have a best rhythm

00:09:23.480 | of either being a morning person,

00:09:24.940 | you called yourself an early person,

00:09:26.760 | or a night owl,

00:09:28.180 | or more of a kind of standard,

00:09:29.880 | you know,

00:09:30.360 | to bed around 10.30,

00:09:31.380 | up around 7 type thing.

00:09:33.420 | And I think there are now good data,

00:09:35.760 | correct me if I'm wrong,

00:09:36.640 | from the National Institutes of Mental Health

00:09:38.960 | and elsewhere showing that

00:09:40.080 | the more we deviate

00:09:41.440 | from that intrinsic rhythm,

00:09:43.620 | the more mental health issues

00:09:45.560 | and physical health issues

00:09:46.720 | start to crop up.

00:09:47.580 | So there is great data on this

00:09:49.420 | and there is a couple of things

00:09:50.500 | that complicate this.

00:09:51.580 | The first is

00:09:52.560 | the people who usually are late.

00:09:54.880 | What do you mean?

00:09:55.380 | People that wake up late

00:09:56.280 | and go to sleep late?

00:09:56.800 | Go to sleep late and wake up late.

00:09:58.360 | They have an overwhelmingly

00:10:00.540 | higher level of depression

00:10:02.140 | because human notice

00:10:04.100 | that people who go to sleep early

00:10:05.620 | and wake up early,

00:10:06.460 | they do better in life.

00:10:07.600 | They notice that.

00:10:08.440 | They just perform better.

00:10:09.440 | They perform.

00:10:09.940 | But the question is,

00:10:11.040 | is that intrinsic to the system

00:10:13.500 | or is that society?

00:10:14.560 | Because society starts things

00:10:16.060 | usually early or late.

00:10:17.220 | That's a hard question.

00:10:18.120 | We discriminate against late risers.

00:10:19.880 | In a way, we discriminate.

00:10:21.260 | And I'm not so sure

00:10:22.680 | that the circadian system

00:10:23.820 | is that variable

00:10:24.840 | in the human population.

00:10:26.020 | I mean, clearly,

00:10:26.760 | there are maybe

00:10:27.540 | some genetic factors

00:10:28.640 | that make a small percentage

00:10:30.660 | of like everything

00:10:31.760 | with a bell shape.

00:10:32.600 | But I think most of the time,

00:10:34.940 | the light environment

00:10:36.060 | may play a role.

00:10:37.040 | And once,

00:10:37.700 | as we've talked about,

00:10:39.400 | this is a long-term effect of light.

00:10:41.300 | Once you get into a rhythm,

00:10:43.380 | it's hard to break

00:10:44.860 | out of that rhythm

00:10:46.200 | because if you start sleeping late

00:10:47.880 | and waking up late,

00:10:48.920 | you're not getting

00:10:50.000 | the morning sunlight.

00:10:50.900 | Right.

00:10:51.480 | And so you're just

00:10:53.160 | going to be late.

00:10:53.960 | It seems to me

00:10:55.120 | is the case

00:10:56.200 | is that the only way

00:10:57.860 | to really know

00:10:58.840 | if you're meant

00:10:59.920 | to be an early bird,

00:11:01.700 | as they call it,

00:11:02.440 | an early person

00:11:03.100 | or a late person

00:11:03.940 | or somewhere in between

00:11:05.480 | is to get morning sunlight

00:11:07.040 | and figure out

00:11:07.840 | whether or not

00:11:08.160 | that makes you feel better.

00:11:09.440 | So what should people do

00:11:11.520 | in the afternoon

00:11:13.040 | slash evening time

00:11:14.520 | in terms of their

00:11:15.220 | light viewing behavior?

00:11:16.060 | I mean,

00:11:16.720 | the best thing to do

00:11:17.800 | is to let the natural light

00:11:19.420 | creep in into darkness,

00:11:20.820 | right?

00:11:21.280 | That would be the best.

00:11:22.840 | but clearly

00:11:23.640 | that would be inefficient.

00:11:25.100 | You want to go home,

00:11:27.120 | you want to read,

00:11:27.880 | you want to talk

00:11:28.620 | to your kids,

00:11:29.380 | you want to talk

00:11:30.820 | to your family.

00:11:31.520 | So I think,

00:11:32.300 | you know,

00:11:32.780 | it's nice to extend the day.

00:11:34.180 | I don't think that's wrong

00:11:35.320 | if you somehow

00:11:36.040 | can block

00:11:37.040 | that light

00:11:38.420 | from affecting

00:11:39.140 | your circadian clock.

00:11:40.320 | you do keep your home

00:11:41.340 | quite dim to dark

00:11:42.940 | at night.

00:11:43.440 | I am an extreme,

00:11:44.920 | but I measured it

00:11:45.980 | for myself

00:11:46.560 | and I asked Reiji,

00:11:47.420 | my wife,

00:11:47.960 | if she's okay with it.

00:11:49.080 | She also liked the dimness.

00:11:50.380 | Both of us can see well

00:11:51.520 | in dim conditions,

00:11:53.200 | but I think you have

00:11:54.280 | to measure it for yourself.

00:11:55.360 | You really have to do,

00:11:57.600 | it's a very simple experiment.

00:11:59.020 | Just try to dim the light

00:12:00.540 | as much as you can.

00:12:01.640 | I call it the minimum

00:12:03.220 | amount of light

00:12:04.220 | you require to see

00:12:05.660 | comfortably.

00:12:06.480 | You know,

00:12:07.100 | use red light

00:12:08.700 | that is very dim

00:12:09.580 | if you want to keep

00:12:10.320 | the room for sleeping.

00:12:11.900 | Red light

00:12:12.860 | that is very dim

00:12:13.680 | has very small effect

00:12:15.700 | on circadian clock

00:12:18.100 | and below 10 lux of red light

00:12:20.540 | literally doesn't affect

00:12:21.460 | sleep at all.

00:12:22.320 | So there are ways to do it.

00:12:24.800 | I've seen you

00:12:25.540 | check your phone

00:12:26.520 | after dark

00:12:27.620 | once or twice

00:12:28.880 | and you did it

00:12:30.460 | by sort of

00:12:31.480 | pointing your phone

00:12:32.540 | away from you, right?

00:12:34.060 | It actually makes sense

00:12:35.100 | that, you know,

00:12:35.600 | if you shine a flashlight

00:12:36.440 | in your eye,

00:12:37.060 | it's much brighter

00:12:37.640 | than if you shine

00:12:38.240 | a flashlight on the camera.

00:12:38.960 | direct line.

00:12:39.720 | So if you just look

00:12:40.640 | on the side,

00:12:41.300 | most of the light

00:12:42.180 | is going to go this way

00:12:43.140 | and you're on the same.

00:12:43.940 | And even when I check

00:12:45.560 | sometimes,

00:12:46.020 | I check it so fast

00:12:47.180 | and switch it off so fast.

00:12:48.260 | So ideally,

00:12:48.860 | I should not check

00:12:50.120 | iPhones and iPads.

00:12:51.280 | I don't use iPad at night

00:12:52.700 | because it's hard

00:12:53.480 | to lower it enough

00:12:54.500 | because it's a huge.

00:12:55.960 | But even my iPhone,

00:12:57.880 | I try not to use it at night.

00:12:59.580 | You had a,

00:13:00.320 | what I consider

00:13:01.580 | absolutely landmark,

00:13:03.220 | beautiful paper

00:13:04.200 | published in Nature

00:13:05.180 | a few years ago

00:13:06.220 | showing that

00:13:07.720 | if you disrupt

00:13:09.440 | the exposure to light

00:13:12.420 | or the timing

00:13:13.440 | of the exposure to light,

00:13:14.600 | that there are dramatic effects

00:13:16.360 | on the stress system

00:13:17.680 | and on the learning

00:13:18.860 | and memory system.

00:13:19.820 | So if I interpret

00:13:21.640 | that correctly,

00:13:22.300 | that could mean

00:13:23.880 | that when we view light

00:13:26.300 | and how much light

00:13:27.380 | could make us feel happier

00:13:30.180 | or less happy

00:13:31.220 | or even depressed,

00:13:32.100 | stressed,

00:13:32.720 | learning, etc.

00:13:33.560 | Bingo.

00:13:35.460 | Even if we're sleeping

00:13:36.660 | and waking up

00:13:38.400 | at the appropriate time.

00:13:39.260 | Bingo.

00:13:39.580 | I mean,

00:13:40.260 | eventually,

00:13:40.920 | because we're talking

00:13:42.260 | about the whole system,

00:13:43.400 | eventually,

00:13:43.900 | when you start having

00:13:44.980 | the other problems,

00:13:45.780 | you also develop

00:13:46.740 | sleep problems.

00:13:47.620 | But you're absolutely right.

00:13:49.560 | And in fact,

00:13:50.240 | now,

00:13:50.880 | research from Diego Fernandez

00:13:53.020 | in the lab

00:13:53.580 | have found that

00:13:54.940 | now we know

00:13:56.020 | that they actually require

00:13:57.400 | different brain regions.

00:13:58.440 | so we don't only have

00:13:59.580 | a theory,

00:14:00.160 | we don't only have

00:14:01.360 | a light environment

00:14:02.220 | that showed

00:14:02.780 | they can be dissociated.

00:14:04.140 | We know that they use

00:14:05.640 | completely different

00:14:06.520 | brain regions.

00:14:07.180 | So the SCN

00:14:08.600 | that I told you about earlier,

00:14:09.920 | the place where

00:14:10.660 | the central pacemaker

00:14:11.720 | is the one that receives

00:14:12.940 | direct input

00:14:13.620 | from the retina

00:14:14.440 | through the IPRGCs

00:14:15.900 | to adjust your circadian clock

00:14:17.680 | is not the area

00:14:19.940 | that receives the light input

00:14:21.360 | for mood regulation.

00:14:22.360 | It's a completely

00:14:23.380 | different brain region.

00:14:24.380 | And what's really amazing,

00:14:25.520 | this region also receives

00:14:26.940 | direct input

00:14:27.600 | from the IPRGCs

00:14:28.800 | but projects to areas

00:14:30.360 | in the brain

00:14:30.880 | that are known

00:14:31.700 | to regulate mood

00:14:32.640 | including the ventral medial

00:14:34.280 | prefrontal cortex

00:14:36.480 | which has been studied

00:14:38.180 | for many years

00:14:39.280 | to be impacted

00:14:40.500 | in a human depression.

00:14:41.800 | So just by

00:14:43.860 | this amazing serendipity

00:14:46.200 | to find

00:14:46.760 | that a region

00:14:48.280 | that is so deep

00:14:49.300 | in the advanced brain

00:14:51.400 | like the prefrontal cortex

00:14:53.460 | is your executive brain

00:14:55.380 | is your executive brain

00:14:55.400 | one of the most

00:14:56.320 | elaborated in humans

00:14:58.300 | to see that

00:14:59.240 | they receive input

00:15:00.400 | from these ancient

00:15:01.440 | photoreceptor

00:15:02.400 | was stunning to us.

00:15:04.240 | How does that

00:15:05.340 | finding inform

00:15:06.920 | daily protocols

00:15:08.600 | for you

00:15:09.220 | or for other people?

00:15:10.080 | So that's why

00:15:10.920 | we came up

00:15:11.500 | with the tripartite model

00:15:12.840 | because as a circadian biologist

00:15:15.060 | I only thought of light

00:15:16.400 | through the circadian clock

00:15:17.500 | affecting behavior.

00:15:18.440 | As a sleep biologist

00:15:19.940 | they only thought

00:15:20.600 | of the homeostatic drive

00:15:21.960 | affecting sleep

00:15:23.040 | affecting behavior

00:15:23.920 | and for people

00:15:25.320 | who study light

00:15:26.040 | for vision

00:15:26.700 | and other things

00:15:27.300 | they thought only

00:15:27.920 | of the environmental input

00:15:29.200 | but now if you put them

00:15:30.700 | all together

00:15:31.460 | you get with this

00:15:32.360 | tripartite model

00:15:33.360 | where it's really

00:15:34.220 | mind-boggling

00:15:34.980 | and it makes so much sense.

00:15:36.580 | The organism

00:15:37.700 | doesn't want to depend

00:15:38.660 | on a single component

00:15:39.900 | but if you could

00:15:40.940 | incorporate these three together

00:15:42.680 | you could have

00:15:44.100 | a beautiful system

00:15:45.180 | that is well adapted.

00:15:46.280 | So let me tell you

00:15:47.500 | the sleep-wake cycle, right?

00:15:49.080 | So we know there is

00:15:49.860 | a homeostatic drive

00:15:50.940 | to affect sleep.

00:15:52.240 | You've had beautiful

00:15:53.380 | talks about that.

00:15:54.520 | Which is basically

00:15:55.120 | the longer you're awake

00:15:56.080 | the more you want to be asleep.

00:15:57.180 | So that's your homeostatic drive.

00:15:58.560 | We've talked about

00:15:59.840 | the circadian influence

00:16:01.000 | of sleep

00:16:01.520 | and the fact that

00:16:02.520 | light-dark cycle

00:16:03.360 | affect the circadian system

00:16:04.620 | which eventually

00:16:05.900 | affects sleep.

00:16:06.740 | So these two components

00:16:07.760 | are well understood.

00:16:08.460 | Now the third factor

00:16:10.140 | is your direct light

00:16:11.400 | or environmental input.

00:16:12.600 | How much stress

00:16:13.640 | how much light

00:16:14.400 | you get from there

00:16:15.080 | also can highly

00:16:16.220 | impact sleep.

00:16:17.560 | So even if you have

00:16:18.520 | a good circadian

00:16:19.460 | and homeostatic drive

00:16:20.880 | if you're getting

00:16:21.820 | light at the wrong

00:16:22.940 | time of the day

00:16:23.700 | or if you're being

00:16:24.440 | stressed and thinking

00:16:25.520 | then your sleep

00:16:26.720 | is going to suffer.

00:16:27.360 | So you have to think

00:16:28.820 | of the three together

00:16:29.900 | to have a beautiful

00:16:31.820 | sleep-wake cycle.

00:16:32.900 | Let's talk about food

00:16:34.620 | and eating

00:16:35.500 | and appetite.

00:16:36.320 | You had yet another

00:16:39.000 | yes, I greatly admire

00:16:42.360 | your success

00:16:43.140 | success in this way.

00:16:44.100 | Yet another

00:16:45.040 | incredible discovery

00:16:46.100 | showing that

00:16:47.540 | there are direct

00:16:48.300 | effects of light

00:16:50.780 | on appetite

00:16:52.040 | and feeding behavior.

00:16:53.200 | So for somebody

00:16:54.940 | who's interested

00:16:56.320 | in affecting

00:16:57.300 | their eating behavior

00:16:59.100 | how should they

00:16:59.900 | use light

00:17:00.640 | in order to

00:17:01.540 | adjust their

00:17:02.400 | eating behavior?

00:17:03.380 | Right.

00:17:03.760 | So now that

00:17:05.020 | I've told you

00:17:05.660 | about all these

00:17:06.400 | interactions

00:17:06.980 | between the different

00:17:08.080 | inputs to the

00:17:08.940 | circadian clock

00:17:09.700 | just you think

00:17:11.540 | about it

00:17:11.880 | as an engineer

00:17:12.560 | what would be

00:17:13.200 | the best thing?

00:17:13.980 | The best thing

00:17:14.820 | is to know

00:17:15.660 | when your food

00:17:17.040 | times happen

00:17:18.060 | in the day

00:17:18.700 | when should you

00:17:19.560 | get light

00:17:20.140 | and when is

00:17:22.100 | your circadian

00:17:22.780 | clock in your system?

00:17:23.760 | Right?

00:17:24.140 | So if you eat

00:17:26.340 | at very specific

00:17:27.280 | times of the day

00:17:28.200 | that's another

00:17:29.280 | signal that is

00:17:30.160 | telling your body

00:17:30.960 | your clock

00:17:31.520 | you're in a certain

00:17:32.240 | time of the day.

00:17:33.000 | So if you're

00:17:34.020 | having lunch

00:17:34.660 | at the correct

00:17:35.220 | time every day

00:17:36.040 | and you're

00:17:36.540 | getting bright light

00:17:37.420 | now you have

00:17:38.060 | two systems

00:17:39.140 | that are

00:17:39.620 | informing your

00:17:40.300 | clock

00:17:40.600 | your clock

00:17:41.400 | is going to

00:17:41.720 | be better.

00:17:42.180 | So regular

00:17:43.120 | mealtimes.

00:17:43.800 | Regular mealtimes

00:17:45.000 | that fit

00:17:45.720 | your circadian

00:17:46.640 | clock.

00:17:47.000 | So and in fact

00:17:48.100 | if you do that

00:17:49.220 | when I started

00:17:50.060 | doing this

00:17:50.820 | and it helped

00:17:51.720 | me lose weight

00:17:52.480 | is that I'm

00:17:53.680 | exposing myself

00:17:54.460 | to the right

00:17:55.100 | amount of light

00:17:56.220 | dark cycle

00:17:56.820 | I'm eating

00:17:57.440 | at regular time

00:17:58.360 | it is amazing

00:17:59.720 | you will be

00:18:00.320 | not hungry

00:18:00.960 | let's say

00:18:01.360 | let's say

00:18:01.740 | you eat at noon

00:18:02.440 | you will not

00:18:03.120 | feel any hunger

00:18:04.000 | at 11.45

00:18:04.900 | and then all

00:18:06.040 | of a sudden

00:18:06.380 | the hunger

00:18:07.160 | jumps in

00:18:08.020 | this is clearly

00:18:08.780 | not an energy

00:18:09.520 | issue

00:18:09.860 | because it

00:18:10.660 | could not

00:18:11.060 | be that

00:18:11.620 | drastic.

00:18:12.140 | Right.

00:18:12.380 | No the desire

00:18:13.000 | to eat

00:18:13.400 | is mainly

00:18:14.000 | driven by

00:18:14.580 | these

00:18:14.960 | these cues

00:18:16.920 | these hormone

00:18:17.780 | cues

00:18:18.200 | that are

00:18:19.340 | very exquisitely

00:18:20.900 | timed

00:18:21.480 | to

00:18:22.200 | sleep-wake cycle

00:18:23.640 | but also

00:18:24.320 | to light.

00:18:25.080 | Exactly.

00:18:25.600 | How regular

00:18:27.280 | are you

00:18:28.100 | or do you

00:18:28.940 | recommend people

00:18:29.520 | be about

00:18:29.920 | mealtimes?

00:18:30.540 | Are we talking

00:18:31.260 | about down

00:18:31.660 | to the minute?

00:18:32.620 | like if I

00:18:33.060 | absolutely

00:18:33.400 | not.

00:18:33.660 | All right

00:18:34.280 | plus or

00:18:34.900 | so 12 noon

00:18:35.900 | is my normal

00:18:36.500 | lunch

00:18:36.900 | let's say

00:18:37.740 | plus or minus

00:18:39.440 | half an hour.

00:18:40.460 | Okay.

00:18:40.960 | Yeah.

00:18:41.380 | So eat

00:18:41.840 | around

00:18:42.340 | between 11.30

00:18:43.320 | and 12.30

00:18:44.180 | if that's the

00:18:45.360 | time

00:18:45.700 | and it depends

00:18:46.420 | if you also

00:18:47.060 | do multiple meals

00:18:48.040 | remember

00:18:48.500 | three meals

00:18:49.540 | that's a decision

00:18:50.320 | that somebody

00:18:51.280 | came up with

00:18:51.920 | I don't know

00:18:52.420 | why.

00:18:52.680 | Nowadays

00:18:53.040 | fewer people

00:18:54.140 | are doing that

00:18:54.720 | I think.

00:18:54.960 | Yeah.

00:18:55.180 | Given our

00:18:56.100 | friend Sachin

00:18:56.700 | Panda's work.

00:18:57.500 | right.

00:18:57.740 | I mean

00:18:58.220 | so you

00:18:58.520 | could have

00:18:58.920 | two meals

00:18:59.620 | you could

00:19:00.060 | have

00:19:00.500 | very

00:19:01.500 | multiple

00:19:02.160 | meals

00:19:03.180 | that are

00:19:03.780 | distributed

00:19:04.420 | across your

00:19:05.040 | active time.

00:19:05.980 | Some people

00:19:06.940 | are not hungry

00:19:07.780 | early in the

00:19:08.400 | day.

00:19:08.640 | They might

00:19:09.120 | be late

00:19:09.520 | shifted people

00:19:10.180 | in which case

00:19:10.740 | eating later

00:19:11.340 | in the day

00:19:11.700 | will work

00:19:12.340 | well for them.

00:19:12.940 | It will work

00:19:13.140 | as long as

00:19:13.660 | they don't eat

00:19:14.200 | early in the

00:19:14.680 | morning.

00:19:14.940 | That's just

00:19:15.560 | you have to

00:19:16.220 | work with

00:19:16.720 | your schedule

00:19:17.380 | with your

00:19:17.760 | active

00:19:18.180 | schedule.

00:19:18.660 | What we're

00:19:19.380 | talking about

00:19:19.820 | really is

00:19:20.240 | finding your

00:19:20.860 | ideal sleep

00:19:21.560 | schedule

00:19:22.040 | and finding

00:19:23.920 | your ideal

00:19:24.500 | eating

00:19:25.080 | schedule

00:19:25.520 | and

00:19:26.520 | understanding

00:19:27.060 | how those

00:19:27.640 | two things

00:19:28.060 | interact.

00:19:28.620 | And you

00:19:29.220 | know the

00:19:29.460 | nice thing

00:19:29.880 | as you

00:19:30.260 | said

00:19:30.440 | finding them

00:19:31.100 | out is

00:19:31.520 | going to

00:19:31.780 | help you

00:19:32.140 | to understand

00:19:32.600 | how they

00:19:32.940 | interact

00:19:33.380 | because we

00:19:34.300 | know from

00:19:34.720 | the

00:19:34.900 | tripartite

00:19:35.560 | model that

00:19:36.120 | they are

00:19:36.480 | all

00:19:36.840 | interconnected

00:19:37.460 | and for

00:19:38.680 | each person

00:19:39.420 | they're going

00:19:39.740 | to be

00:19:39.980 | interconnected

00:19:40.520 | differently.

00:19:41.380 | It's striking

00:19:42.660 | to me that

00:19:43.260 | in all

00:19:44.200 | animals

00:19:44.800 | besides

00:19:45.680 | humans

00:19:46.360 | if they

00:19:47.480 | deviate

00:19:48.060 | too much

00:19:48.680 | from the

00:19:49.240 | appropriate

00:19:49.760 | exposure to

00:19:50.520 | light and

00:19:50.980 | light-dark

00:19:51.420 | cycle

00:19:51.780 | they essentially

00:19:52.600 | don't mate

00:19:53.820 | and or

00:19:54.420 | die and

00:19:55.780 | or get

00:19:56.140 | killed off.

00:19:56.740 | but in

00:19:57.760 | humans

00:19:58.220 | we are

00:19:58.980 | able to

00:19:59.380 | override that

00:20:00.100 | at least

00:20:00.460 | to some

00:20:00.820 | extent.

00:20:01.260 | But the

00:20:02.120 | ways in

00:20:02.660 | which we

00:20:03.140 | suffer

00:20:03.980 | appear to

00:20:05.240 | be things

00:20:05.720 | like obesity

00:20:06.940 | metabolic

00:20:07.480 | syndromes

00:20:08.480 | reproductive

00:20:09.440 | syndromes that

00:20:10.480 | accompany the

00:20:11.180 | other syndromes

00:20:11.920 | you know

00:20:12.140 | endocrine

00:20:12.600 | syndromes

00:20:13.100 | and mood

00:20:14.440 | and depressive

00:20:15.000 | disorders.

00:20:15.600 | Is there

00:20:16.640 | any effort

00:20:17.340 | at the level

00:20:18.360 | of the

00:20:18.740 | nationally

00:20:20.460 | or laboratories

00:20:21.680 | that you're

00:20:22.120 | aware of

00:20:22.500 | to try

00:20:23.220 | to try

00:20:23.220 | and use

00:20:23.760 | light in

00:20:24.720 | order to

00:20:25.360 | improve mood

00:20:26.380 | and mental

00:20:26.880 | health?

00:20:27.160 | I mean

00:20:27.780 | honestly this

00:20:28.580 | is my

00:20:28.940 | moonshot.

00:20:29.380 | This is the

00:20:30.160 | thing that I

00:20:30.760 | think people

00:20:31.460 | because it's

00:20:32.840 | I say don't

00:20:34.360 | take a pill

00:20:34.860 | take a photon

00:20:35.600 | and not I

00:20:36.580 | mean you take

00:20:37.060 | pills it's

00:20:37.560 | important.

00:20:38.000 | I'm just

00:20:38.520 | making it

00:20:39.100 | that really

00:20:40.240 | we have an

00:20:41.000 | opportunity

00:20:41.560 | right now

00:20:42.460 | with the

00:20:43.020 | incredible

00:20:43.840 | advances of

00:20:44.620 | LED lights

00:20:45.460 | of changing

00:20:46.080 | spectra of

00:20:46.800 | light of

00:20:48.100 | regulating

00:20:48.880 | intensities

00:20:50.100 | and just

00:20:51.800 | for simple

00:20:53.560 | changes you

00:20:54.240 | could really

00:20:54.860 | improve sleep

00:20:55.820 | wake cycle

00:20:56.520 | productivity

00:20:57.200 | and still

00:20:58.480 | you could

00:20:58.820 | actually get

00:20:59.540 | more done

00:21:00.460 | because as

00:21:01.740 | we've talked

00:21:02.180 | about when you

00:21:02.900 | have all these

00:21:03.700 | messed up

00:21:04.360 | now you have

00:21:05.180 | to sleep

00:21:05.580 | more but your

00:21:06.620 | sleep is

00:21:07.060 | fragmented

00:21:07.780 | it's not very

00:21:08.620 | good.

00:21:08.980 | And you can't

00:21:09.780 | focus when you

00:21:10.500 | can't focus

00:21:11.260 | when you don't

00:21:11.700 | have alertness

00:21:12.500 | when you need

00:21:13.000 | the alertness

00:21:13.880 | so having

00:21:15.360 | all these

00:21:15.960 | could allow

00:21:16.900 | you to do

00:21:17.340 | even more

00:21:18.200 | actually at

00:21:18.980 | the end

00:21:19.440 | than less

00:21:20.140 | and that's

00:21:20.800 | the exciting

00:21:21.540 | part of it.

00:21:22.280 | Let's talk

00:21:22.920 | about jet lag

00:21:24.340 | what are the

00:21:25.680 | two or three

00:21:26.240 | things that

00:21:26.780 | people can do

00:21:27.440 | to adjust

00:21:28.260 | their schedule

00:21:29.480 | quickly like

00:21:30.280 | let's say fall

00:21:30.880 | classes are

00:21:31.500 | starting you

00:21:31.920 | start a new

00:21:32.400 | job or you

00:21:32.900 | have a baby

00:21:33.440 | or a puppy

00:21:33.980 | or whatever

00:21:34.480 | what is the

00:21:35.840 | best way to

00:21:36.360 | shift the

00:21:36.800 | clock quickly?

00:21:37.660 | So it's

00:21:38.560 | very simple

00:21:39.100 | as we've

00:21:39.560 | talked yesterday

00:21:40.220 | so imagine

00:21:41.000 | you're in

00:21:41.480 | the outside

00:21:42.420 | with no

00:21:43.000 | environmental

00:21:43.620 | with no

00:21:44.640 | industrial

00:21:45.220 | light

00:21:45.700 | if you

00:21:47.240 | if your

00:21:47.720 | body thinks

00:21:48.280 | you're in

00:21:48.820 | early evening

00:21:49.640 | and you

00:21:50.120 | see a bright

00:21:50.820 | light what

00:21:51.660 | does this

00:21:52.100 | tell you?

00:21:52.500 | Oh wait

00:21:53.360 | this is not

00:21:54.260 | early evening

00:21:54.980 | yet it's

00:21:55.640 | still early

00:21:56.480 | afternoon or

00:21:57.540 | late afternoon

00:21:58.220 | so I have

00:21:59.520 | to delay my

00:22:00.340 | clock to go

00:22:01.280 | back to late

00:22:01.960 | afternoon so

00:22:02.940 | if you get

00:22:03.840 | light early

00:22:04.920 | in the evening

00:22:05.640 | it delays

00:22:06.540 | your clock

00:22:07.200 | so what does

00:22:08.340 | meaning that

00:22:08.820 | makes you want

00:22:09.380 | to go to

00:22:09.700 | sleep later?

00:22:10.260 | yes it

00:22:11.160 | delays your

00:22:11.540 | clock so

00:22:11.940 | later in

00:22:12.940 | the night

00:22:13.560 | later in

00:22:14.480 | your night

00:22:15.220 | and actually

00:22:16.780 | it just

00:22:17.300 | happens that

00:22:18.220 | in humans

00:22:18.700 | you get a

00:22:19.220 | temperature

00:22:19.660 | in a deer

00:22:20.160 | later in

00:22:20.940 | the night

00:22:21.320 | low temperature

00:22:22.320 | in your body

00:22:22.920 | after that

00:22:24.140 | lights start

00:22:25.060 | advancing your

00:22:25.980 | clock

00:22:26.300 | if I understand

00:22:27.380 | correctly what

00:22:27.980 | you're saying

00:22:28.420 | is if your

00:22:30.160 | typical wake up

00:22:30.840 | time is say

00:22:31.920 | 7 a.m

00:22:32.600 | then your

00:22:34.100 | low point in

00:22:34.900 | temperature probably

00:22:35.740 | occurs somewhere

00:22:36.420 | around 5 a.m

00:22:37.440 | and if you

00:22:39.020 | view light

00:22:39.780 | right around

00:22:40.820 | then it's going

00:22:42.140 | to essentially

00:22:42.700 | advance your

00:22:43.420 | clock

00:22:43.700 | yeah because

00:22:44.420 | then your

00:22:44.920 | body thinks

00:22:46.080 | oh it's 7 o'clock

00:22:46.940 | so advance your

00:22:47.700 | clock by 1 to

00:22:48.540 | 2 hours

00:22:49.120 | but if I were

00:22:49.900 | to view light

00:22:50.580 | say at 3 a.m

00:22:52.080 | then it would

00:22:53.600 | probably delay

00:22:54.340 | my clock

00:22:54.940 | yeah

00:22:55.220 | okay

00:22:55.640 | yeah so

00:22:56.780 | and then let's

00:22:57.820 | say I land

00:22:58.660 | in a new

00:22:59.060 | schedule

00:22:59.440 | I want to

00:22:59.860 | adjust to a

00:23:00.300 | new schedule

00:23:00.640 | let's say I

00:23:01.040 | didn't manage

00:23:01.760 | to do anything

00:23:02.300 | with my light

00:23:02.880 | viewing before

00:23:03.460 | I went

00:23:03.800 | and I didn't

00:23:04.180 | anticipate the

00:23:05.440 | trip

00:23:05.640 | suddenly I'm

00:23:06.480 | on a new

00:23:06.880 | schedule

00:23:07.280 | okay

00:23:07.740 | I was told

00:23:09.200 | that one

00:23:10.220 | of the ways

00:23:10.680 | to help

00:23:11.080 | shift the

00:23:11.520 | clock

00:23:11.840 | and to

00:23:12.360 | avoid

00:23:12.660 | gastrointestinal

00:23:13.620 | issues

00:23:14.200 | is to

00:23:14.840 | eat on

00:23:15.900 | the local

00:23:16.260 | schedule

00:23:16.720 | to start

00:23:18.160 | basically behaving

00:23:19.340 | like a local

00:23:20.040 | even though

00:23:21.320 | your circadian

00:23:22.420 | clock will take

00:23:23.040 | a little bit

00:23:23.400 | of time

00:23:23.660 | to catch up

00:23:24.220 | absolutely

00:23:24.660 | but you have

00:23:25.880 | to remember

00:23:26.280 | the light

00:23:26.840 | right

00:23:27.340 | so let's

00:23:28.260 | let's now

00:23:28.820 | that we

00:23:29.180 | explained it

00:23:29.700 | very simply

00:23:30.260 | let's take

00:23:30.840 | a very simple

00:23:31.480 | example

00:23:31.980 | right

00:23:32.360 | New York

00:23:33.600 | to Italy

00:23:34.120 | that's a

00:23:34.900 | simple example

00:23:35.700 | New York

00:23:36.580 | time

00:23:36.820 | Italy

00:23:37.080 | time

00:23:37.340 | six hour

00:23:37.860 | difference

00:23:38.320 | right

00:23:38.660 | so let's

00:23:39.640 | say you fly

00:23:40.260 | from New York

00:23:40.900 | at night

00:23:41.540 | you reach

00:23:42.400 | Italy at

00:23:43.100 | eight o'clock

00:23:43.620 | in the morning

00:23:44.140 | what is the

00:23:44.760 | time in your

00:23:45.480 | New York

00:23:45.840 | time

00:23:46.200 | although you

00:23:47.640 | reach

00:23:47.800 | six hours

00:23:48.260 | back

00:23:48.540 | six hours

00:23:49.040 | it's 2 a.m

00:23:50.340 | so when you land

00:23:51.580 | Italy

00:23:52.000 | you want to

00:23:52.640 | avoid light

00:23:53.500 | like the plague

00:23:54.380 | yeah you could

00:23:55.080 | eat

00:23:55.440 | but you really

00:23:56.260 | don't want to

00:23:56.720 | get a light

00:23:57.160 | because otherwise

00:23:57.720 | it's going to

00:23:58.220 | delay

00:23:58.460 | it's going to

00:23:59.540 | send you to

00:24:00.000 | California

00:24:00.540 | instead of

00:24:01.040 | sending you to

00:24:01.660 | Italy

00:24:01.960 | what Sam

00:24:02.660 | is saying

00:24:03.000 | is so

00:24:03.460 | crucial

00:24:03.920 | just because

00:24:05.600 | getting bright

00:24:06.520 | light in your

00:24:07.000 | eyes early

00:24:07.660 | in the day

00:24:08.120 | is really

00:24:08.560 | beneficial

00:24:08.980 | when you're

00:24:09.360 | at home

00:24:09.680 | when you travel

00:24:10.340 | to a new

00:24:10.760 | time zone

00:24:11.340 | you have to

00:24:12.200 | take into

00:24:12.560 | account where

00:24:13.460 | your body

00:24:13.960 | thinks you

00:24:14.460 | are

00:24:14.660 | and so if

00:24:15.100 | you're looking

00:24:15.460 | at the

00:24:15.720 | Italian

00:24:16.080 | sunrise

00:24:16.560 | having just

00:24:17.400 | flown from

00:24:17.940 | New York

00:24:18.260 | to Italy

00:24:18.680 | and you

00:24:19.360 | didn't

00:24:19.620 | prepare for

00:24:20.200 | that trip

00:24:20.620 | by waking

00:24:21.060 | up a little

00:24:21.480 | bit earlier

00:24:21.920 | in anticipation

00:24:22.700 | multiple days

00:24:23.560 | and you view

00:24:24.060 | light at

00:24:24.560 | 2 a

00:24:25.040 | excuse me

00:24:25.900 | at 6 or

00:24:26.880 | 7 a.m

00:24:27.560 | Italian time

00:24:28.760 | beautiful

00:24:29.120 | Italian sunrise

00:24:30.080 | you are going

00:24:31.160 | to delay

00:24:31.760 | your clock

00:24:32.240 | you're going

00:24:32.640 | to basically

00:24:33.140 | throw yourself

00:24:34.020 | back to

00:24:34.580 | California

00:24:35.060 | but you are

00:24:35.580 | in Italy

00:24:36.000 | you're going

00:24:36.660 | to throw

00:24:36.880 | your biology

00:24:37.540 | back to

00:24:37.980 | California

00:24:38.320 | and you

00:24:38.740 | are going

00:24:38.960 | to be

00:24:39.200 | up in

00:24:39.680 | the middle

00:24:40.040 | of the

00:24:40.300 | Italian

00:24:40.640 | night

00:24:41.000 | and you're

00:24:41.660 | going

00:24:41.740 | to be

00:24:41.880 | miserable

00:24:42.720 | miserable

00:24:43.280 | it's

00:24:44.040 | very

00:24:44.400 | important

00:24:45.020 | to avoid

00:24:46.540 | getting the

00:24:47.420 | wrong light

00:24:47.860 | information

00:24:48.400 | when you're

00:24:48.840 | trying to

00:24:49.260 | adjust

00:24:49.620 | your body

00:24:50.080 | because

00:24:50.460 | otherwise

00:24:51.140 | it shifts

00:24:51.660 | you to the

00:24:52.080 | other side

00:24:53.300 | absolutely

00:24:53.960 | right

00:24:54.440 | you are

00:24:55.360 | one of

00:24:55.600 | these people

00:24:56.100 | that has

00:24:56.780 | such vigor

00:24:57.460 | I think

00:24:58.100 | a lot

00:24:58.440 | of your

00:24:58.720 | ability

00:24:59.040 | to work

00:24:59.540 | hard

00:24:59.880 | and focus

00:25:00.460 | and really

00:25:00.900 | do so

00:25:01.460 | many

00:25:01.740 | things

00:25:02.300 | at an

00:25:02.680 | impressive

00:25:02.980 | level

00:25:03.400 | is because

00:25:04.260 | you think

00:25:04.660 | about these

00:25:05.100 | issues

00:25:05.400 | and you

00:25:05.860 | think about

00:25:06.800 | when you're

00:25:07.320 | going to be

00:25:07.840 | optimal

00:25:08.340 | for focus

00:25:09.180 | when you're

00:25:09.660 | going to be

00:25:10.020 | optimal

00:25:10.340 | for exercise

00:25:11.060 | and the

00:25:12.180 | when is

00:25:12.800 | the key

00:25:13.240 | and I think

00:25:14.540 | a lot of

00:25:14.940 | people live

00:25:15.440 | in the

00:25:15.680 | landscape

00:25:16.020 | of feeling

00:25:16.560 | like

00:25:16.780 | there's

00:25:17.000 | something

00:25:17.260 | broken

00:25:17.700 | inside

00:25:18.200 | them

00:25:18.520 | I really

00:25:19.480 | agree

00:25:19.920 | with you

00:25:20.260 | that I

00:25:20.640 | think

00:25:20.800 | part of

00:25:21.240 | the reason

00:25:21.580 | I'm

00:25:21.900 | continuing

00:25:22.300 | to be

00:25:22.780 | able

00:25:23.080 | to do

00:25:23.460 | this

00:25:23.700 | that

00:25:23.960 | I

00:25:24.700 | really

00:25:25.000 | think

00:25:25.300 | about

00:25:25.620 | it

00:25:25.820 | and I

00:25:26.120 | make sure

00:25:26.760 | that I

00:25:27.380 | keep

00:25:27.720 | everything

00:25:28.300 | aligned

00:25:28.940 | and that

00:25:29.980 | actually helps

00:25:30.780 | me a lot

00:25:31.280 | like I

00:25:31.740 | don't suffer

00:25:32.940 | in sleep

00:25:33.540 | I don't suffer

00:25:34.240 | in waking up

00:25:34.840 | I never

00:25:35.380 | use a timer

00:25:36.120 | to wake up

00:25:36.880 | system

00:25:37.540 | is so aligned

00:25:38.840 | it works

00:25:39.580 | a lot

00:25:39.800 | a lot

00:25:40.400 | a lot

00:25:40.400 | of times

00:25:40.760 | people

00:25:41.060 | will say

00:25:41.500 | how come

00:25:41.920 | I go

00:25:42.200 | to sleep

00:25:42.640 | I fall

00:25:43.000 | asleep

00:25:43.300 | fine

00:25:43.680 | but then

00:25:44.060 | I wake

00:25:44.420 | up at

00:25:44.640 | three or

00:25:44.920 | four in

00:25:45.160 | the morning

00:25:45.460 | and can't

00:25:45.900 | fall back

00:25:46.320 | asleep

00:25:46.660 | is it

00:25:47.440 | possible

00:25:47.840 | that those

00:25:48.280 | people were

00:25:48.740 | supposed to

00:25:49.220 | go to bed

00:25:49.600 | at 8pm

00:25:50.240 | yeah I mean

00:25:50.960 | it is possible

00:25:51.720 | or it's possible

00:25:53.080 | that their clock

00:25:53.960 | is completely

00:25:54.640 | misaligned

00:25:55.240 | that they are

00:25:56.180 | getting maybe

00:25:56.940 | enough time

00:25:57.740 | at night

00:25:58.220 | when they are

00:25:58.680 | supposed

00:25:58.920 | and then they

00:25:59.400 | possibly feel

00:26:00.040 | so sleepy

00:26:00.660 | in the day

00:26:01.160 | so there

00:26:01.580 | all these

00:26:02.240 | are possible

00:26:02.800 | combinations

00:26:03.460 | that's an

00:26:04.020 | interesting idea

00:26:04.560 | and considered

00:26:05.240 | so I mean

00:26:05.820 | that what they

00:26:06.360 | think is their

00:26:06.960 | sleep

00:26:07.380 | their body

00:26:08.020 | is so out

00:26:08.760 | of whack

00:26:09.280 | with the

00:26:09.580 | light dark

00:26:09.940 | cycle

00:26:10.220 | that it's

00:26:10.640 | actually a

00:26:11.240 | nap

00:26:11.380 | or the

00:26:12.500 | weaker

00:26:12.860 | part of

00:26:13.400 | the sleep

00:26:13.800 | I mean

00:26:14.100 | you see

00:26:14.500 | this in

00:26:15.080 | when you

00:26:16.140 | travel to

00:26:16.660 | different

00:26:16.920 | time zone

00:26:17.360 | before you

00:26:17.880 | adjust

00:26:18.400 | you go to

00:26:19.720 | sleep

00:26:20.020 | really well

00:26:20.640 | but two

00:26:21.060 | hours later

00:26:21.660 | you're

00:26:22.040 | fully up

00:26:22.680 | two hours

00:26:23.700 | if you were

00:26:24.580 | so tired

00:26:25.200 | and this

00:26:25.620 | is your

00:26:25.900 | regular

00:26:26.200 | sleep

00:26:26.560 | there's

00:26:26.880 | no way

00:26:27.460 | you're

00:26:28.040 | going to

00:26:28.180 | wake up

00:26:28.560 | in two

00:26:28.920 | hours

00:26:29.320 | let's

00:26:29.960 | talk about

00:26:30.380 | seasonality

00:26:31.160 | a little

00:26:31.500 | bit

00:26:31.760 | are there

00:26:32.600 | other

00:26:32.920 | effects

00:26:33.640 | of

00:26:33.840 | seasonality

00:26:34.460 | on humans

00:26:34.940 | that we

00:26:35.240 | are aware

00:26:35.660 | of

00:26:36.120 | honestly

00:26:36.500 | you could

00:26:36.820 | see it

00:26:37.220 | perfectly

00:26:37.700 | I think

00:26:38.320 | in

00:26:38.860 | in

00:26:39.320 | Scandinavia

00:26:40.000 | I mean

00:26:40.300 | you could

00:26:40.680 | talk to

00:26:41.180 | people

00:26:41.520 | who live

00:26:42.480 | in

00:26:42.780 | sure

00:26:43.260 | they get

00:26:43.660 | seasonal

00:26:44.120 | depression

00:26:44.620 | what

00:26:45.100 | seasonal

00:26:45.560 | depression

00:26:45.940 | is one

00:26:46.360 | but actually

00:26:46.840 | when you

00:26:47.120 | start

00:26:47.420 | asking

00:26:47.840 | them

00:26:48.080 | questions

00:26:48.560 | they tell

00:26:49.200 | you

00:26:49.340 | like

00:26:49.560 | in the

00:26:49.940 | winter

00:26:50.260 | they

00:26:50.540 | barely

00:26:51.040 | could

00:26:51.320 | wake

00:26:51.640 | up

00:26:51.960 | they

00:26:52.540 | barely

00:26:53.020 | have

00:26:53.360 | the

00:26:53.540 | energy

00:26:53.860 | before

00:26:54.280 | even

00:26:54.580 | depression

00:26:55.060 | even

00:26:55.520 | people

00:26:55.820 | who

00:26:56.000 | don't

00:26:56.180 | get

00:26:56.360 | seasonal

00:26:56.720 | depression

00:26:57.200 | they'll

00:26:57.920 | tell you

00:26:58.200 | our

00:26:58.460 | energy

00:26:58.960 | level

00:26:59.280 | is lower

00:26:59.740 | our

00:27:00.080 | ability

00:27:00.560 | to go

00:27:00.880 | to work

00:27:01.360 | is not

00:27:02.520 | the same

00:27:03.000 | and in

00:27:03.320 | the summer

00:27:03.880 | most people

00:27:05.260 | actually sleep

00:27:05.980 | very little

00:27:06.580 | they tell

00:27:07.120 | you we

00:27:07.480 | really can

00:27:08.600 | we feel

00:27:10.120 | like we're

00:27:10.600 | manic

00:27:10.880 | we have

00:27:11.320 | all this

00:27:11.720 | energy

00:27:12.340 | and not

00:27:13.420 | in a

00:27:13.680 | negative

00:27:13.960 | way

00:27:14.380 | in a

00:27:14.660 | funny

00:27:14.840 | way

00:27:15.040 | right

00:27:15.360 | I mean

00:27:15.760 | but if

00:27:16.400 | you want

00:27:16.640 | to sleep

00:27:16.940 | we have

00:27:17.260 | to put

00:27:17.560 | this

00:27:17.840 | curtain

00:27:18.200 | I think

00:27:19.200 | in these

00:27:19.720 | situations

00:27:20.480 | you could

00:27:21.320 | really

00:27:21.840 | appreciate

00:27:22.600 | the seasonality

00:27:23.600 | of humans

00:27:24.180 | I think

00:27:24.740 | we kind

00:27:25.600 | of

00:27:25.740 | destroyed

00:27:26.260 | our

00:27:26.560 | seasonality

00:27:27.300 | because we

00:27:27.900 | don't get

00:27:28.560 | exposed

00:27:29.120 | to that

00:27:30.500 | much

00:27:30.800 | natural

00:27:31.220 | light

00:27:31.480 | we have

00:27:31.820 | all this

00:27:32.280 | artificial

00:27:32.680 | light

00:27:33.120 | but I

00:27:33.480 | think

00:27:33.880 | honestly

00:27:34.360 | one of

00:27:35.380 | the things

00:27:35.720 | that is

00:27:36.280 | going to

00:27:36.580 | happen

00:27:36.900 | if they

00:27:37.500 | follow

00:27:37.860 | your

00:27:38.080 | recommendation

00:27:38.600 | this is

00:27:39.400 | going to

00:27:39.700 | cause

00:27:39.960 | them to

00:27:40.320 | also

00:27:40.700 | experience

00:27:41.600 | some

00:27:41.900 | changes

00:27:42.420 | across

00:27:42.760 | the

00:27:42.980 | season

00:27:43.260 | because

00:27:43.620 | now

00:27:44.160 | they're

00:27:45.140 | going to

00:27:45.280 | see

00:27:45.420 | the

00:27:45.620 | sun

00:27:45.820 | differently

00:27:46.420 | if

00:27:46.800 | you're

00:27:47.100 | going to

00:27:47.260 | go out

00:27:47.760 | in the

00:27:48.080 | morning

00:27:48.460 | in the

00:27:49.440 | summer

00:27:49.720 | you're

00:27:50.040 | going to

00:27:50.160 | get

00:27:50.340 | much

00:27:50.780 | bright

00:27:51.100 | that's

00:27:51.380 | why I

00:27:51.600 | don't

00:27:51.740 | like

00:27:51.940 | the

00:27:52.100 | change

00:27:52.380 | in

00:27:52.560 | time

00:27:52.820 | I

00:27:52.980 | know

00:27:53.240 | people

00:27:54.060 | think

00:27:54.320 | oh

00:27:54.500 | because

00:27:54.800 | you're

00:27:55.060 | biased

00:27:55.520 | you

00:27:55.860 | because

00:27:56.480 | I

00:27:56.660 | think

00:27:56.880 | wait

00:27:57.120 | wait

00:27:57.420 | sorry

00:27:58.000 | the

00:27:58.240 | change

00:27:58.460 | time

00:27:58.580 | you're

00:27:58.700 | talking

00:27:58.860 | about

00:27:59.020 | daylight

00:27:59.340 | savings

00:27:59.780 | daylight

00:28:00.100 | saving

00:28:00.540 | it's such

00:28:01.160 | a bad

00:28:01.520 | idea

00:28:02.040 | because

00:28:02.460 | it disrupts

00:28:03.420 | that rhythm

00:28:04.100 | that you're

00:28:04.760 | having

00:28:05.160 | because I

00:28:06.240 | think

00:28:06.460 | your body

00:28:07.000 | if you

00:28:07.880 | keep

00:28:08.140 | that

00:28:08.360 | rhythm

00:28:08.620 | you will

00:28:09.000 | see

00:28:09.200 | the

00:28:09.400 | whole

00:28:09.640 | seasonality

00:28:10.360 | and I

00:28:10.780 | look at

00:28:11.320 | it from

00:28:11.660 | a different

00:28:12.160 | aspect

00:28:12.580 | than

00:28:12.820 | other

00:28:13.080 | people

00:28:13.420 | if

00:28:14.020 | you

00:28:14.140 | think

00:28:14.380 | about

00:28:14.680 | it

00:28:14.900 | there

00:28:15.440 | is

00:28:15.600 | a

00:28:15.780 | situation

00:28:16.400 | where

00:28:16.960 | you're

00:28:17.560 | getting

00:28:17.840 | light

00:28:18.140 | perfectly

00:28:18.680 | well

00:28:18.940 | and

00:28:19.140 | then

00:28:19.300 | all

00:28:19.540 | of

00:28:19.660 | sudden

00:28:19.840 | they

00:28:20.000 | delay

00:28:20.280 | it

00:28:20.420 | by

00:28:20.580 | one

00:28:20.820 | hour

00:28:21.120 | because

00:28:21.480 | and

00:28:22.200 | then

00:28:22.440 | even

00:28:23.400 | though

00:28:23.620 | it's

00:28:23.820 | the

00:28:24.020 | summer

00:28:24.320 | your body

00:28:24.860 | now

00:28:25.120 | if

00:28:25.340 | you're

00:28:25.560 | still

00:28:25.900 | not

00:28:26.280 | adjusting

00:28:26.840 | think

00:28:27.240 | oh

00:28:27.580 | wait

00:28:27.900 | what

00:28:28.120 | happened

00:28:28.580 | what

00:28:28.980 | kind

00:28:29.220 | of

00:28:29.360 | happened

00:28:29.740 | well

00:28:29.980 | I'm

00:28:30.160 | glad

00:28:30.320 | you're

00:28:30.500 | bringing

00:28:30.680 | this

00:28:30.900 | up

00:28:31.080 | because

00:28:31.420 | I

00:28:32.200 | always

00:28:32.520 | thought

00:28:32.900 | you know

00:28:33.520 | what's

00:28:33.780 | the big

00:28:34.100 | deal

00:28:34.380 | one

00:28:34.680 | hour

00:28:35.020 | right

00:28:35.500 | one

00:28:35.720 | hour

00:28:35.920 | shift

00:28:36.240 | you know

00:28:36.440 | spring

00:28:36.700 | forward

00:28:37.120 | just

00:28:38.000 | one

00:28:38.320 | hour

00:28:38.660 | but

00:28:39.620 | the

00:28:39.860 | but

00:28:40.160 | this

00:28:40.940 | goes

00:28:41.140 | back

00:28:41.380 | to

00:28:41.520 | the

00:28:41.660 | beginning

00:28:42.000 | of

00:28:42.200 | our

00:28:42.340 | discussion

00:28:42.800 | it's

00:28:43.260 | not

00:28:43.560 | just

00:28:43.860 | one

00:28:44.160 | hour

00:28:44.440 | right

00:28:44.760 | because

00:28:45.360 | it's

00:28:45.640 | one

00:28:45.860 | hour

00:28:46.200 | across

00:28:46.620 | that

00:28:46.860 | one

00:28:47.100 | day

00:28:47.420 | but

00:28:47.640 | there's

00:28:47.880 | this

00:28:48.060 | cumulative

00:28:48.520 | effect

00:28:49.040 | on

00:28:49.240 | the

00:28:49.380 | clock

00:28:49.760 | and

00:28:50.100 | these

00:28:50.420 | three

00:28:51.460 | elements

00:28:51.900 | of

00:28:52.120 | your

00:28:52.380 | tripartite

00:28:53.500 | model

00:28:53.900 | homeostatic

00:28:54.920 | sleep

00:28:55.340 | and the

00:28:55.800 | light

00:28:56.040 | direct

00:28:56.420 | effects

00:28:56.760 | on

00:28:56.960 | mood

00:28:57.200 | and

00:28:57.400 | when

00:28:57.560 | it's

00:28:57.840 | so

00:28:58.040 | close

00:28:58.520 | it's

00:28:58.820 | sometimes

00:28:59.180 | hard

00:28:59.620 | to

00:28:59.900 | figure

00:29:00.660 | out

00:29:00.960 | how

00:29:01.120 | to

00:29:01.280 | adjust

00:29:01.680 | it

00:29:01.880 | perfectly

00:29:02.400 | because

00:29:02.840 | we're

00:29:03.760 | already

00:29:04.120 | sleep

00:29:04.500 | deprived

00:29:04.920 | in

00:29:05.120 | our

00:29:05.340 | society

00:29:05.860 | and

00:29:06.080 | then

00:29:06.260 | you

00:29:06.420 | shift

00:29:06.780 | it

00:29:07.020 | by

00:29:07.240 | you

00:29:07.900 | know

00:29:08.020 | so

00:29:08.220 | it

00:29:08.460 | just

00:29:08.900 | it

00:29:09.280 | all

00:29:09.600 | accumulates

00:29:10.260 | and

00:29:10.440 | it

00:29:10.640 | has

00:29:11.040 | no

00:29:11.400 | benefit

00:29:11.880 | I

00:29:12.360 | just

00:29:12.580 | don't

00:29:12.820 | understand

00:29:13.200 | why

00:29:13.460 | they

00:29:13.620 | do

00:29:13.800 | this

00:29:14.100 | it

00:29:14.320 | makes

00:29:14.580 | no

00:29:14.780 | sense

00:29:15.140 | well

00:29:15.660 | I

00:29:15.880 | think

00:29:16.120 | that

00:29:16.380 | the

00:29:16.820 | reason

00:29:17.100 | they

00:29:17.300 | do

00:29:17.580 | it

00:29:17.780 | is

00:29:18.120 | because

00:29:18.340 | they

00:29:18.500 | don't

00:29:18.780 | understand

00:29:19.220 | the

00:29:19.380 | biology

00:29:19.800 | because

00:29:20.660 | one

00:29:21.000 | hour

00:29:21.260 | seems

00:29:21.660 | trivial

00:29:22.200 | unless

00:29:22.680 | you

00:29:22.900 | understand

00:29:23.540 | the

00:29:23.940 | repercussions

00:29:25.000 | of

00:29:25.260 | that

00:29:25.420 | one

00:29:25.640 | hour

00:29:25.860 | shift

00:29:26.220 | because

00:29:26.880 | what's

00:29:27.800 | also

00:29:28.020 | clear

00:29:28.400 | now

00:29:28.800 | based

00:29:29.220 | on

00:29:29.340 | what

00:29:29.460 | you're

00:29:29.600 | saying

00:29:29.840 | is

00:29:30.020 | that

00:29:30.200 | that

00:29:30.380 | one

00:29:30.600 | hour

00:29:30.800 | shift

00:29:31.100 | is

00:29:31.280 | taking

00:29:31.580 | you

00:29:32.000 | out

00:29:32.480 | of

00:29:32.600 | alignment

00:29:33.000 | with

00:29:33.260 | the

00:29:33.400 | natural

00:29:33.700 | light

00:29:33.920 | dark

00:29:34.180 | cycle

00:29:34.500 | in

00:29:34.940 | exactly

00:29:35.480 | the

00:29:35.760 | wrong

00:29:36.220 | direction

00:29:36.820 | it's

00:29:37.160 | pushing

00:29:37.440 | people

00:29:37.860 | to

00:29:38.040 | get

00:29:38.200 | even

00:29:38.480 | later

00:29:38.960 | in

00:29:39.820 | the

00:29:40.020 | summer

00:29:40.300 | when

00:29:40.580 | light

00:29:40.900 | is

00:29:41.040 | going

00:29:41.180 | to

00:29:41.280 | push

00:29:41.480 | you

00:29:41.600 | later

00:29:41.920 | anyway

00:29:42.440 | it's

00:29:43.340 | really

00:29:43.740 | compounding

00:29:44.700 | the

00:29:44.820 | problem

00:29:45.160 | that

00:29:45.340 | already

00:29:45.680 | exists

00:29:46.200 | Samer

00:29:47.600 | this

00:29:47.960 | has

00:29:48.160 | been

00:29:48.460 | an

00:29:49.560 | amazing

00:29:50.180 | march

00:29:50.860 | through

00:29:51.320 | the

00:29:51.860 | importance

00:29:52.360 | of

00:29:52.580 | light

00:29:52.840 | I'm

00:29:53.420 | certain

00:29:53.660 | that

00:29:53.940 | people

00:29:54.660 | are

00:29:55.120 | going

00:29:55.440 | to

00:29:55.680 | start

00:29:56.000 | thinking

00:29:56.340 | about

00:29:56.620 | how

00:29:56.860 | to

00:29:57.020 | change

00:29:57.260 | their

00:29:57.420 | relationship

00:29:57.900 | with

00:29:58.540 | light

00:29:58.840 | as

00:29:59.060 | a

00:29:59.200 | way

00:29:59.360 | to

00:29:59.600 | anchor

00:29:59.940 | everything

00:30:00.560 | that

00:30:01.600 | they

00:30:02.080 | do

00:30:02.320 | and

00:30:02.460 | that's

00:30:02.660 | important

00:30:02.980 | to

00:30:03.160 | their

00:30:03.320 | health

00:30:03.560 | let's

00:30:03.980 | talk

00:30:04.160 | a

00:30:04.260 | little

00:30:04.340 | bit

00:30:04.460 | about

00:30:04.600 | where

00:30:04.760 | people

00:30:05.100 | can

00:30:05.280 | find

00:30:05.540 | you

00:30:05.660 | your

00:30:05.840 | laboratories

00:30:06.280 | at

00:30:06.460 | the

00:30:06.560 | National

00:30:06.800 | Institutes

00:30:07.240 | of

00:30:07.380 | Mental

00:30:07.620 | Health

00:30:07.960 | he's

00:30:08.660 | head

00:30:08.840 | of

00:30:08.940 | the

00:30:09.020 | chronobiology

00:30:09.640 | unit

00:30:09.940 | all

00:30:10.080 | these

00:30:10.240 | things

00:30:10.440 | that

00:30:10.580 | I've

00:30:10.740 | mentioned

00:30:11.000 | earlier

00:30:11.460 | but

00:30:12.320 | you

00:30:13.400 | are

00:30:13.600 | active

00:30:14.040 | on

00:30:14.480 | Twitter

00:30:14.720 | and

00:30:14.880 | Instagram

00:30:15.240 | right

00:30:15.740 | so

00:30:16.080 | what

00:30:16.340 | is

00:30:16.460 | your

00:30:16.680 | Twitter

00:30:17.340 | handle

00:30:17.740 | it's

00:30:18.260 | at

00:30:18.500 | Samer

00:30:18.900 | Hattar

00:30:19.420 | and

00:30:19.760 | I

00:30:19.900 | think

00:30:20.080 | the

00:30:20.260 | same

00:30:20.460 | for

00:30:20.680 | Instagram

00:30:21.160 | definitely

00:30:21.620 | give him

00:30:21.980 | a

00:30:22.100 | follow

00:30:22.320 | there

00:30:22.700 | and

00:30:23.040 | on

00:30:23.520 | Twitter

00:30:23.880 | and

00:30:24.660 | I'm

00:30:26.140 | sure

00:30:26.440 | that

00:30:26.600 | he'll

00:30:26.720 | be

00:30:26.840 | happy

00:30:27.080 | to

00:30:27.420 | answer

00:30:27.760 | questions

00:30:28.400 | and

00:30:29.620 | entertain

00:30:31.040 | any

00:30:31.500 | and

00:30:31.800 | all

00:30:31.960 | discussions

00:30:32.400 | about

00:30:32.800 | chronobiology

00:30:33.780 | absolutely

00:30:34.440 | yeah

00:30:35.020 | and light

00:30:35.740 | yeah

00:30:36.640 | great

00:30:37.740 | thank you

00:30:38.200 | Samer

00:30:38.500 | awesome

00:30:38.880 | thank you

00:30:39.440 | Andrew

00:30:39.720 | you

00:30:41.780 | you

Essentials: Timing Light for Better Sleep, Energy & Mood | Dr. Samer Hattar

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