[0:00] ANDREW HUBERMAN: Welcome to
Huberman Lab Essentials, where
[0:02] we revisit past episodes for
the most potent and actionable
[0:06] science based tools for mental
health, physical health,
[0:08] and performance.
[0:09] [MUSIC PLAYING]
[0:11] I'm Andrew Huberman,
and I'm a professor
[0:13] of neurobiology
and ophthalmology
[0:15] at Stanford School of Medicine.
[0:17] Today's podcast episode
is all about sleep.
[0:21] We're also going to talk about
the mirror image of sleep,
[0:24] which is wakefulness.
[0:25] Now, these two phases of our
life, sleep and wakefulness
[0:29] govern everything about our
mental and physical health.
[0:33] And we're not just going to talk
about what's useful about sleep.
[0:37] We're also going to talk about
how to get better at sleeping,
[0:40] and that will include
how to get better
[0:41] at falling asleep,
timing your sleep
[0:44] and accessing better
sleep quality.
[0:47] In doing so, we're
also going to discuss
[0:48] how to get more focused
and alert in wakefulness.
[0:52] So if you're like most
people, which includes me,
[0:56] you have some
challenges with sleep.
[0:58] At least every third
or fifth night or so,
[1:00] and maybe even more often.
[1:02] So we're really going
to go tool heavy today
[1:04] and talk about tools that
can help you fall asleep,
[1:07] sleep better and emerge from
sleep feeling more rested.
[1:11] So what determines
how well we sleep
[1:13] and the quality of
our wakeful state?
[1:16] It turns out that's
governed by two forces.
[1:19] The first force is
a chemical force.
[1:21] It's called adenosine.
[1:23] Adenosine is a molecule in
our nervous system and body
[1:27] that builds up the
longer we are awake.
[1:30] So if you've just slept for
eight or nine or ten really
[1:34] deep restful hours,
adenosine is going
[1:36] to be very low in
your brain and body.
[1:39] If, however, you've been awake
for 10, 15 or more hours,
[1:43] adenosine levels are
going to be much higher.
[1:46] Adenosine creates a sort of
sleep drive or a sleep hunger.
[1:50] And a good way to remember
this and think about adenosine
[1:54] is to think about caffeine.
[1:56] Caffeine for most
people wakes them up.
[1:59] It makes them feel more alert.
[2:01] Caffeine acts as an
adenosine antagonist.
[2:06] What that means is that when you
ingest caffeine, whether or not
[2:09] it's coffee or soda or
tea or in any other form,
[2:12] it binds to the
adenosine receptor.
[2:15] It sort of parks there
just like a car would
[2:17] park in a given parking slot.
[2:19] And therefore adenosine
can't park in that slot.
[2:22] Now, when caffeine parks in
the adenosine receptor slot,
[2:26] nothing really happens
downstream of that receptor.
[2:30] The receptor can't engage
the normal cellular functions
[2:32] of making that cell
and you feel sleepy.
[2:36] So the reason
caffeine wakes you up
[2:39] is because it blocks
the sleepiness receptor.
[2:42] It blocks the sleepy signal.
[2:44] And this is why when
that caffeine wears off,
[2:47] adenosine will bind
to that receptor
[2:49] sometimes with even greater
what we call affinity.
[2:52] And you feel the crash,
you feel especially tired.
[2:55] Caffeine has a lot
of health benefits.
[2:58] It also, for some people, can
be problematic for health,
[3:01] it can raise blood
pressure, et cetera.
[3:03] Caffeine increases this
molecule that's a neuromodulator
[3:07] that we call dopamine.
[3:08] We discussed this in
episode one, which
[3:10] tends to make us feel good,
motivated and give us energy,
[3:14] because as you may have
learned in episode one,
[3:17] dopamine is related to
another neuromodulator called
[3:21] epinephrine, which
gives us energy.
[3:22] In fact, epinephrine
is made from dopamine.
[3:25] So let's just take a
step back and think
[3:27] about what we're
talking about when
[3:28] we're talking about sleepiness.
[3:30] If you've ever pulled
an all-nighter,
[3:31] you'll noticed
something interesting.
[3:33] As morning rolls
around, you'll suddenly
[3:36] feel an increase in your
energy and alertness
[3:38] again, even though adenosine
has been building up
[3:41] for the entire night.
[3:44] Now, why is that?
[3:45] The reason that
is because there's
[3:47] a second force which is
governing when you sleep
[3:50] and when you're awake.
[3:51] And that force is a
so-called circadian force.
[3:55] Circadian means about a
day or about 24 hours.
[4:00] And inside all of
us is a clock that
[4:02] exists in your
brain and my brain
[4:05] and the brain of every
animal that we're
[4:07] aware of that determines
when we want to be sleepy
[4:11] and when we want to be awake.
[4:13] That block of sleep and when it
falls within each 24 hour cycle
[4:18] is governed by a number
of different things.
[4:21] But the most
powerful thing that's
[4:23] governing when you
want to be asleep
[4:24] and when you want to
be awake is light.
[4:28] And in particular, it's
governed by sunlight.
[4:31] Now, I can't emphasize
enough how important
[4:33] and how actionable this
relationship is between light
[4:37] and when you want to sleep.
[4:40] It's quite simple
on the face of it,
[4:43] and it's quite
simple to resolve.
[4:44] But people tend to make a big
mess of this whole circadian
[4:47] literature frankly.
[4:49] So let's just break it
down from the standpoint
[4:52] of what's going on in
your brain and body
[4:54] as you go through
one 24 hour day.
[4:58] Let's start with waking.
[4:59] So regardless of how
well you slept at night
[5:01] or whether or not you
were up all night,
[5:03] most people tend
to wake up sometime
[5:05] around when the sun rises.
[5:08] When you wake up
in the morning, you
[5:10] wake up because a
particular hormone
[5:12] called cortisol is released
from your adrenal glands.
[5:16] Your adrenal glands sit
right above your kidneys
[5:18] and there's a little
pulse of cortisol.
[5:20] There's also a pulse
of epinephrine,
[5:22] which is adrenaline from your
adrenals and also in your brain.
[5:27] And you feel awake.
[5:29] Now, that pulse of cortisol
and adrenaline and epinephrine
[5:32] might come from
your alarm clock.
[5:34] It might come from you
naturally waking up.
[5:36] But it tends to alert your
whole system and your body
[5:40] that it's time to
increase your heart rate.
[5:41] It's time to start
tensing your muscles.
[5:43] It's time to start moving about.
[5:45] It's very important
that that cortisol pulse
[5:48] come early in the
day, or at least early
[5:51] in your period of wakefulness.
[5:53] When you wake up in the
morning and you experience
[5:55] that rise in cortisol, there's
a timer that starts going
[6:00] and these are cellular
timers and they're
[6:02] dictated by the relation
between different organs
[6:04] in your body that says
to your brain and body
[6:08] that in about 12 to 14
hours a different hormone.
[6:12] This hormone we're
calling melatonin
[6:14] will be released from
your pineal gland.
[6:16] So there's two mechanisms
here a wakefulness signal
[6:19] and a sleepiness signal.
[6:21] And the wakefulness
signal triggers
[6:23] the onset of the timer
for the sleepiness signal.
[6:26] OK, so the rhythm of
cortisol and melatonin
[6:30] is what we call endogenous.
[6:32] It's happening in us all the
time without any external input.
[6:36] In fact, if we were in complete
darkness, living in a cave
[6:39] with no artificial
lights whatsoever,
[6:41] these rhythms of cortisol
and melatonin would continue.
[6:45] So if you were in
complete darkness,
[6:48] it would happen once
per 24 hour cycle,
[6:51] but it would be somewhat
later and later each day.
[6:55] Whereas under normal
circumstances, what happens
[7:00] is you wake up.
[7:01] And what happens
when you wake up?
[7:03] You open your eyes.
[7:04] When you open your eyes.
[7:06] Light comes into your eyes.
[7:07] Now, the way this
system works is
[7:09] that you have a particular
set of neurons in your eye.
[7:12] They're called retinal
ganglion cells.
[7:14] When light comes
into the eye, there's
[7:16] a particular group of
retinal ganglion cells
[7:18] or type of retinal
ganglion cells
[7:21] that perceives a
particular type of light
[7:24] and communicates that to
this clock that resides right
[7:27] above the roof of
your mouth called
[7:28] the suprachiasmatic nucleus.
[7:30] And the suprachiasmatic
nucleus has
[7:33] connections with
essentially every cell
[7:36] and organ of your body.
[7:38] Now, it's vitally
important that we
[7:40] get light communicated to
this central clock in order
[7:43] to time the cortisol
and melatonin properly.
[7:47] When I say properly, I can
say that with confidence
[7:50] because we know based
on a lot of evidence
[7:52] that if you don't get your
cortisol and melatonin rhythms
[7:56] right, there are
tremendously broad
[8:00] and bad effects on
cardiovascular health,
[8:04] metabolic effects, learning,
depression, dementia.
[8:08] So let's think
about what happens
[8:10] when we do this correctly
and how to do it correctly.
[8:12] When we wake up, our eyes open.
[8:15] Now, if we're in
a dark room, there
[8:17] isn't enough light to
trigger the correct timing
[8:21] of this cortisol
melatonin thing.
[8:24] These rhythms, you might say,
well, why won't any light do it?
[8:28] Well, it turns out
that these neurons
[8:31] in our eye that set
the circadian clock
[8:33] and then allow our
circadian clock to set
[8:35] all the clocks of all the
cells and organs and tissues
[8:38] of our body, responds best to
a particular quality of light
[8:43] an amount of light.
[8:45] And those are the qualities
of light and amount of light
[8:49] that come from sunlight.
[8:51] So these neurons, what
they're really looking for,
[8:56] although they don't have
a mind of their own,
[8:58] is the sun at what we
call low solar angle.
[9:01] The eye and the nervous
system don't know anything
[9:03] about sunrises or sunsets.
[9:05] It only knows the
quality of light
[9:07] that comes in when the
sun is low in the sky.
[9:10] This system evolved so that
when the sun is low in the sky,
[9:14] there's a particular contrast
between yellows and blues
[9:17] that triggers the
activation of these cells.
[9:20] However, if you
wake up a few hours
[9:22] after the sunrise, which I
tend to most days personally,
[9:26] you still want to get
outside and view sunlight.
[9:29] You don't need the sunlight
beaming you directly
[9:32] in the eyes.
[9:33] There's a lot of photons,
light energy that scattered
[9:36] from sunlight at this time.
[9:37] But the key is to get that light
energy from sunlight ideally
[9:43] into your eyes.
[9:44] It's critically important
that you get outside
[9:46] to get this light.
[9:47] I had a discussion with a
colleague of mine, Dr. Jamie
[9:50] Zeitzer, who's in the Department
of Psychiatry and Behavioral
[9:53] Sciences at Stanford,
a world expert in this.
[9:58] And he tells me that it's
50 times less effective
[10:03] to view this sunlight through a
window, through a car windshield
[10:08] or through a side
window of a car
[10:10] than it is to just get outside
with no sunglasses and view
[10:14] light early in the day.
[10:15] Once the sun is overhead,
the quality of light
[10:18] shifts so that you miss
this opportunity to time
[10:22] the cortisol pulse.
[10:23] And that turns out to
be a bad thing to do.
[10:26] You really want to time that
cortisol pulse properly.
[10:29] Because we'll get into this
a little bit more later.
[10:33] But a late shifted cortisol
pulse in particular a 9:00 PM
[10:37] or 8:00 PM increase in cortisol
is one of the consequences
[10:42] and maybe one of the causes
of a lot of anxiety disorders
[10:47] and depression.
[10:48] So it's kind of a
chicken and egg thing.
[10:49] We don't know whether or not
it's the correlated with it's
[10:52] the cause or the
effect, but it's
[10:53] a signature of depression
and anxiety disorder.
[10:56] Bringing that cortisol pulse
earlier in your wakeful period,
[11:00] earlier in your day
has positive benefits,
[11:03] ranging from blood pressure
to mental health etcetera.
[11:06] I'm not going to list them
all off because they're just
[11:09] so many of them.
[11:10] But many, many
positive things happen
[11:12] when you are getting the
cortisol early in the day,
[11:15] far away from your
melatonin pulse.
[11:18] So how long should
you be outside?
[11:21] Well, this is going
to vary tremendously,
[11:23] because some people live
in environments where
[11:24] it's very bright.
[11:25] So let's say it's Colorado
in the middle of winter,
[11:29] there's a snow field,
there's no cloud cover.
[11:31] And you walk outside,
there's going
[11:33] to be so much photon
light energy arriving
[11:36] on your retina that
probably only takes
[11:38] 30 to 60 seconds to
trigger the central clock
[11:41] and set your cortisol
and melatonin
[11:43] rhythms properly and get
everything in lined up nicely.
[11:47] Whereas if you're in Scandinavia
in the depths of winter and you
[11:51] wake up at 5:00 AM and the sun
is just barely creeping across
[11:54] the horizon and then goes back
down again a few hours later,
[11:57] you probably are not getting
enough sunlight in order to set
[12:01] these rhythms.
[12:02] So many people
find that they need
[12:05] to use sunlight simulators in
the form of particular lights
[12:09] that were designed
to simulate sunlight.
[12:11] You could say, well, the
lights in my house or my phone
[12:14] are really, really bright.
[12:15] Everyone's telling us to
stay off our phones at night
[12:17] because they're really bright.
[12:19] But guess what?
[12:20] It turns out that
early in the day,
[12:22] your retina is not
very sensitive,
[12:25] which means you need
a lot of photons,
[12:28] ideally coming from sunlight
to set these clock mechanisms.
[12:31] So looking at your phone
or artificial lights
[12:33] is fine if you wake
up before sunrise,
[12:35] but it's not going to work to
set these clock mechanisms.
[12:40] So you want to use sunlight.
[12:42] If you can't see sunlight
because of your environment,
[12:45] then you are going to have
to opt for artificial light.
[12:48] And in that case, you're going
to want an artificial light
[12:51] that either simulates sunlight
or has a lot of blue light.
[12:54] Now, without going off course
here, you might be saying, wait,
[12:58] I've heard blue
light is bad for me.
[12:59] Actually, blue light is
great for this mechanism
[13:02] during the day.
[13:03] A lot of people will say I
should be wearing blue blockers
[13:06] throughout the day.
[13:07] No, that's the
exact wrong thing.
[13:09] That should be reserved
for late in the evening.
[13:12] Because light
suppresses melatonin.
[13:15] Sunlight inhibits the pineal.
[13:18] It prevents it from
releasing melatonin.
[13:21] Darkness allows the pineal
to release melatonin.
[13:25] So the pineal is not the gland
or the organ of sunlight.
[13:29] It is the gland of darkness.
[13:31] In fact, melatonin
can be thought
[13:33] of as a sleepiness signal
that's correlated with darkness.
[13:36] So get up each morning,
try and get outside.
[13:39] I know that can be
challenging for people,
[13:41] but anywhere from two to ten
minutes of sunlight exposure
[13:45] is going to work
well for most people.
[13:47] If you can't do it
every day or you
[13:48] sleep through this period of
the early day low solar angle,
[13:51] don't worry about it.
[13:53] The systems in the body,
these hormone systems
[13:55] and neurotransmitter
systems that
[13:57] make you awake at certain
periods of the day
[13:59] and sleepy at other
times are operating
[14:03] by averaging when you
view the brightest light.
[14:08] Some of you, many of
you might be asking,
[14:10] what else can help
set this rhythm?
[14:12] Well, it turns out
that light is what
[14:14] we call the primary
zeitgeber, the time giver.
[14:18] But other things
can help establish
[14:21] this rhythm of cortisol,
followed by melatonin
[14:24] 12 to 16 hours later as well.
[14:26] The other things besides light
are timing of food intake,
[14:31] timing of exercise, as well
as various drugs or chemicals
[14:36] that one might ingest.
[14:38] Not illegal drugs,
although those
[14:39] will impact circadian
mechanisms, as well.
[14:42] The other thing is sunset,
when the sun is also
[14:46] at low solar angle low
close to the horizon.
[14:50] By viewing sunlight
at that time of day,
[14:52] in the evening or afternoon,
depending on what time of year
[14:55] it is and where you
are in the world.
[14:57] These melanopsin cells,
these neurons in your eye
[15:00] signal the central
circadian clock
[15:02] that it's the end of the day.
[15:04] There was a really
nice study that
[15:06] showed that viewing sunlight
around the time of sunset
[15:11] doesn't have to be just
crossing the horizon,
[15:13] but circa sunset within
an hour or so of sunset
[15:17] prevents some of the
bad effects of light
[15:22] in preventing melatonin
release later that same night.
[15:26] So let me repeat this viewing
light early in the day is key.
[15:28] Viewing light later
in the day when
[15:31] the sun is setting
or around that time
[15:33] can help protect these
mechanisms, your brain and body
[15:37] against the negative effects
of light later in the day.
[15:41] So let me talk about
how you would do that.
[15:43] You'd go view the sunset
or you would go outside
[15:46] in the late
afternoon or evening.
[15:48] Again, if you want to do this
through a window at work,
[15:50] that's fine, but it'll
take 50 times longer.
[15:52] So the best thing to do
is just to get outside
[15:54] for a few minutes, anywhere
from two to ten minutes also
[15:57] in the afternoon.
[15:58] Having those two
signals arriving
[16:00] to your central
clock that your body,
[16:03] your internal world
knows when it's morning
[16:05] and knows when it's evening
is tremendously powerful.
[16:08] There's always a lot of
questions about how long?
[16:11] How much How do I know
if I've had enough?
[16:12] You'll know because
your rhythm will
[16:14] start to fall into some
degree of normalcy.
[16:18] You'll start to wake up at more
or less the same time each day.
[16:20] You'll fall asleep
more easily at night.
[16:22] Generally, it takes about two
or three days for these systems
[16:24] to align.
[16:25] So if you've not been
doing these behaviors,
[16:27] it's going to take a few days.
[16:29] But they can have
tremendous benefits
[16:31] and sometimes rather
quickly on a number
[16:33] of different mental and
physical aspects of your health.
[16:36] Now let's talk about the
bad effects of light.
[16:39] Because light is not supposed
to arrive in our system
[16:44] at any time.
[16:45] And nowadays, because of
screens and artificial light,
[16:48] we have access to light at times
of day and night that normally
[16:53] we wouldn't.
[16:54] Now, earlier I
said that you need
[16:56] a lot of light in
particular sunlight
[16:58] to set these clock mechanisms.
[17:00] That's true.
[17:01] But there's a kind of
diabolical feature to the way
[17:03] all this works, which is the
longer you've been awake,
[17:07] the more sensitive your retina
and these cells are to light.
[17:11] So that if you've been
awake for 10, 12, 14 hours,
[17:15] it becomes very easy for even
a small amount of light coming
[17:19] from a screen or from
an overhead light
[17:23] to trigger the activation
of the clock and make
[17:26] you feel like you
want to stay up later,
[17:27] make it harder to fall asleep
and disrupt your sleep pattern.
[17:31] OK, so the simple way
to think about this
[17:33] is want as much light
as safely possible
[17:36] early in the day, morning
and throughout the day,
[17:38] including blue light.
[17:40] And you want as little
light coming into your eyes,
[17:43] artificial or sunlight
after, say 8:00 PM.
[17:46] And certainly you do not want
to get bright light exposure
[17:49] to your eyes between
11 PM and 4 AM.
[17:51] And here's why.
[17:52] Light that arrives to the eyes
between 11:00 PM and 4:00 AM
[17:58] approximately, suppresses
the release of dopamine.
[18:04] This neuromodulator
that makes us feel good
[18:06] is sort of an endogenous
antidepressant
[18:09] and can inhibit learning
and create all sorts
[18:11] of other detrimental effects.
[18:14] It does this through a
mechanism for those of you
[18:16] who want to the neural pathways
that involves light to the eyes.
[18:19] That's then signaled to a
structure called the habenula.
[18:22] When that habenula
gets activated,
[18:24] it's actually called the
disappointment nucleus
[18:26] because it actually makes
us feel less happy and more
[18:31] disappointed and can lead to
certain forms of depression
[18:34] in the wakeful state.
[18:35] Now, if you wake up in
the middle of the night
[18:37] and you need to use the bathroom
or you're on an all night flight
[18:40] and you need to read or
whatever it is, fine.
[18:44] Every once in a
while it's not going
[18:46] to be a problem to get bright
light exposure to your eyes
[18:49] in the middle of the night.
[18:50] But if you think
about our lifestyle
[18:52] nowadays and being up
late looking at phones,
[18:55] even if you dim
that screen, you're
[18:57] triggering this activation
because your retinal sensitivity
[19:00] and the sensitivity
of these neurons
[19:01] has gone up late in the day.
[19:03] For those of you that are
experiencing challenges
[19:05] with mood, those of you that
have anxiety, learning problems,
[19:08] issues, focusing, the
questions I usually get
[19:10] are how can I focus better?
[19:11] One of the best ways you
can support your mechanisms
[19:13] for good mood, mental health,
learning, focus, metabolism,
[19:18] et cetera, is to take control
of this light exposure behavior
[19:22] at night and not get much
or any bright light exposure
[19:26] in the middle of the night.
[19:27] These cells in our
eye, these neurons that
[19:30] signal the central
clock reside mostly
[19:33] not exclusively, but mostly in
the bottom half of our retina.
[19:36] And because we have a lens
in front of our retina
[19:39] and because of the
optics of lenses,
[19:41] that means that these
cells are actually
[19:43] viewing our upper visual field.
[19:45] This is probably
not coincidental
[19:48] that these cells
were essentially
[19:51] designed to detect sunlight,
which is overhead, of course.
[19:55] So if you want to avoid improper
activation of these neurons,
[20:02] it's better to place
lights that you
[20:05] use in the evening low in
your physical environment.
[20:08] So on desktops or even the
floor, if you want to go
[20:11] that way as opposed
to overhead lights.
[20:15] So overhead fluorescent
lights would be the worst.
[20:18] That would be the
worst case scenario.
[20:20] Lights that are
overhead that are
[20:22] a little bit softer of the
yellow or reddish tints
[20:25] would be slightly better.
[20:26] But dim lights that
are set low in the room
[20:28] are going to be best
because they aren't going
[20:31] to activate these neurons and
therefore shift your circadian
[20:35] clock.
[20:36] But let's talk
about what light can
[20:39] do in terms of shifting
us in healthy ways.
[20:42] So the way to think about
this whole system again,
[20:45] is you've got
adenosine building up
[20:47] depending on how long
you've been awake
[20:48] and it's making you sleepy.
[20:50] And then you've got their
circadian mechanisms
[20:51] that are timing your
wakefulness and timing
[20:54] when you want to
be asleep, mainly
[20:55] through cortisol and melatonin.
[20:57] But there are a
bunch of other things
[20:58] that are downstream of
cortisol and melatonin
[21:00] like we tend to be hungrier
during our wakeful period
[21:05] than late at night.
[21:06] Some people like to
eat it late at night.
[21:07] But if you're finding that
you can't become a day
[21:10] person or a morning person,
shifting your light exposure,
[21:14] exercise and food intake
to the daytime will help.
[21:17] Jamie Zeitzer and colleagues
did a beautiful study
[21:20] showing that if you turn on
the lights before waking up,
[21:25] so around 45 minutes to
an hour before waking up.
[21:28] Even if your eyelids
are closed provided
[21:30] you're not under the covers.
[21:33] After doing that
for a few days, that
[21:36] increases your total sleep time
and shifts forward the time
[21:40] at which you feel sleepy.
[21:41] It makes you want to go
to bed earlier each night.
[21:44] Now, in a kind of
diabolical way,
[21:47] they did this with
teenagers who are
[21:49] notorious for wanting to wake
up late and stay up late.
[21:51] And what they found was bright
light flashes just turning
[21:53] on the lights in their
environment, overhead lights,
[21:56] because they're trying
to activate the system.
[21:58] And that's why they're
using overhead lights even
[22:00] through the eyelids
before these kids woke up,
[22:03] then made those kids naturally
want to go to bed earlier
[22:06] and they ended up
sleeping longer.
[22:08] So that's something
you could try.
[22:09] You could put your lights on a
timer to go on early in the day
[22:13] before you wake up.
[22:14] You could open your blinds so
that sunlight is coming through.
[22:18] And again, if you curl
up under the covers,
[22:20] then it's not going to
reach these neurons.
[22:23] But it's remarkable,
the light can actually
[22:24] penetrate the eyelids,
activate these neurons
[22:27] and go to the central clock.
[22:29] That study illustrates a
really important principle
[22:31] of how you're
built, which is have
[22:34] the capacity for what are called
phase advances and phase delays.
[22:38] And I don't want to
complicate this too much.
[22:41] So the simplest way to think
about phase advances and phase
[22:45] delays is that if you
see light late in the day
[22:49] and in particular in the
middle of the night, your brain
[22:52] and body, for
reasons that now you
[22:54] understand will think that
that's morning light, even
[22:58] though it's not sunlight,
because you have this heightened
[23:00] sensitivity and it will phase
delay, it will delay your clock.
[23:04] It will essentially make
you want to get up later
[23:06] and go to sleep later.
[23:07] So the simple way
to think about this
[23:09] is if you're having
trouble waking up early
[23:12] and feeling alert
early in the day,
[23:14] you're going to want to try and
get bright light exposure even
[23:17] before waking up because
it will advance your clock.
[23:21] It's sort of like turning
the clock forward.
[23:23] Whereas if you are having
trouble waking up early,
[23:26] you definitely don't want to
get too much light exposure
[23:29] or any light exposure to
your eyes late in the evening
[23:31] and in the middle of the night
because it's just going to delay
[23:34] your clock more and more.
[23:36] And what you're trying to
do is provide them anchors.
[23:39] You're trying to provide them
consistent, powerful anchors so
[23:43] that your cortisol, your
melatonin, and then everything
[23:46] that cascades down from
that, like your metabolism
[23:49] and your ability to learn
and your sense of alertness,
[23:52] your dopamine, your
serotonin, all that stuff
[23:55] is timed regularly.
[23:58] One of the reasons
why there's so much
[24:00] challenge out there with focus
and anxiety and depression.
[24:06] There are a lot of
reasons for that.
[24:07] But one of the reasons is that
people's internal mechanisms
[24:11] aren't anchored to
anything regular.
[24:13] These systems,
again, will average,
[24:15] but if you can provide them
consistent light anchors early
[24:18] in the day and in the evening
and avoiding light at night,
[24:21] you will be amazed at
the tremendous number
[24:24] of positive effects
that can come
[24:25] from that at the level of
metabolic factors, hormones,
[24:29] and just general
feelings of well-being.
[24:31] And this is why whenever people
ask me, what should I take?
[24:34] Which is one of the most
common questions I get.
[24:36] What supplements should I take?
[24:37] What drugs should I be taking?
[24:39] What things should I be taking?
[24:40] The first question I always
ask them is how is your sleep?
[24:45] And 90% of the time
they tell me they
[24:47] either have trouble falling
asleep or staying asleep
[24:50] or they don't feel rested
throughout the day.
[24:52] A brief note about naps.
[24:54] Naps provided that they're
less than one ultradian cycle,
[24:58] provided they're 20
minutes or 30 minutes
[24:59] or even an hour can be very
beneficial for a lot of people.
[25:02] You don't have to take them,
but many people naturally
[25:06] feel a dip in energy and
focus late in the afternoon.
[25:09] In fact, if we were going
to look at wakefulness, what
[25:11] we would find is that you get
that morning light exposure,
[25:13] hopefully your cortisol goes
up, people start feeling awake
[25:15] and then around 2 or 3
or 4 in the afternoon,
[25:18] there's a spike in everything
from alertness to ability
[25:22] to learn.
[25:23] Some metabolic factors drop
and then it just naturally
[25:25] comes back up.
[25:26] And then it tapers off
as the night goes on.
[25:29] So for some of you,
naps are great.
[25:32] I love taking naps.
[25:33] Some people, they wake up from
naps, feeling really groggy.
[25:36] That's probably
because they're not
[25:38] sleeping as well as
they should at night
[25:40] or as long as they
should at night.
[25:42] And so they're dropping into REM
sleep or deeper forms of sleep
[25:46] in the daytime.
[25:47] And then they wake up and
they feel kind of disoriented.
[25:49] Other people feel
great after a nap.
[25:51] So that's another case where
just like with caffeine,
[25:53] you sort of have to
evaluate for yourself.
[25:55] OK, so naps are going to be good
for some people, not for others.
[25:58] I personally like to take
a nap around 3 or 4 PM,
[26:01] but there's a practice that I've
adopted in the last five years
[26:05] that I've found to be
immensely beneficial.
[26:08] That is sort of like
napping but isn't napping.
[26:10] It's a thing that
they call yoga nidra.
[26:14] Yoga nidra actually
means yoga sleep.
[26:16] And it's a sort of meditation
that you listen to.
[26:19] Meditation and
yoga nidra scripts
[26:21] have been immensely
helpful for me
[26:23] in terms of accelerating
the transition to sleep.
[26:26] So they involve taking a few
minutes, 10 to 30 minutes or so,
[26:31] just like you would
for a nap and just
[26:33] listening to a script
almost passively,
[26:35] and it has do some particular
patterns of breathing
[26:38] and some other kind of body
scan things that can really
[26:42] help people learn to relax,
not just in that moment,
[26:45] but get better at
relaxing and turning off
[26:48] thinking in order
to fall asleep when
[26:49] they want to do that at night.
[26:51] In other words, they're
always good for you
[26:53] because it's a training
mechanism by which you self
[26:55] train your nervous system to
go from a state of heightened
[26:59] alertness, that you
don't want to heighten,
[27:01] relaxation that you do want.
[27:03] And so it's really teaching
you to hit the brake.
[27:06] And that brings us to an even
more important point, perhaps,
[27:09] which is we've all experienced
that we can stay up
[27:13] if we want to.
[27:14] If we want to stay up
late on New Year's or we
[27:17] want to push an all-nighter.
[27:18] Some people can do that
more easily than others,
[27:20] but we're all capable
of doing that.
[27:23] But it's very hard to make
ourselves fall asleep.
[27:26] And so there's a sort
of asymmetry to the way
[27:28] our autonomic
nervous system, which
[27:30] governs this alertness,
calmness thing,
[27:32] the sympathetic and
parasympathetic nervous system,
[27:34] there's an asymmetry
there where we
[27:36] are more easily able to
engage wakefulness and drive
[27:40] wakefulness.
[27:40] We can force ourselves
to stay awake
[27:43] than we are able to force
ourselves to fall asleep.
[27:46] And one of the things that
I say over and over again
[27:49] and I'm going to continue
to say over and over again
[27:51] is it's very hard to control
the mind with the mind.
[27:54] When you have trouble
falling asleep,
[27:56] you need to look to
some mechanism that
[27:58] involves the body.
[27:59] And all the things I described
meditation, hypnosis, yoga
[28:02] nidra, all involve
exhale, emphasized,
[28:06] breathing certain ways of lying
down and controlling the body.
[28:10] We're going to get into
breathing in real depth
[28:12] at another time.
[28:13] But all of those involve using
the body to control the mind
[28:16] rather than trying to wrestle
your mind into a certain pattern
[28:21] of relaxation.
[28:22] And when we're having
trouble controlling the mind,
[28:25] I encourage people to
look towards the body,
[28:27] look toward sunlight, avoid
sunlight and bright light
[28:30] if that happens to
be late at night.
[28:32] So there's a theme that's
starting to emerge,
[28:34] which is in order to control
this thing that we call
[28:36] the nervous system,
we have to look back
[28:38] to some of the things
we discussed earlier,
[28:40] like sensation,
perception, etcetera.
[28:42] But we have to ask,
what can we control?
[28:45] Well, I'm talking about
controlling light exposure,
[28:47] controlling your
breathing and body,
[28:49] non-sleep deep rest
or what I hereafter
[28:52] we will refer to as NSDR
non-sleep deep rest as a way
[28:58] to reset one's
ability to be awake
[29:01] after you emerge from NSDR.
[29:03] So to get some more
wakefulness and ability
[29:05] to attend some emotional
stability reset,
[29:08] as well as make it
better and easier
[29:11] to fall asleep when you want
to go to sleep at night.
[29:14] Now, non-sleep deep rest
does have some research
[29:17] to support it.
[29:18] There's a beautiful study done
out of a university in Denmark.
[29:22] I will later provide a
link to that study that
[29:25] showed that this meditation
and yoga nidra type
[29:29] meditation allows dopamine
and other neuromodulators
[29:33] in an area of the brain
called the striatum that's
[29:35] involved in motor planning and
motor execution to reset itself.
[29:39] In other words, this NSDR
can reset our ability
[29:43] to engage in the world in a
way that's very deliberate.
[29:46] OK, so what about things
that we can and maybe
[29:49] should or should
not take in order
[29:51] to control and access better
sleep and better wakefulness?
[29:55] There are a couple
of things that
[29:56] are directly in line
with the biology
[29:58] related to falling and
staying asleep and directly
[30:00] in line with the
biology of wakefulness.
[30:03] There's a whole category of
things like stimulants, cocaine,
[30:07] amphetamine and
prescription stimulants
[30:10] that are the
prescription ones were
[30:12] designed for the
treatment of narcolepsy.
[30:13] So things like
modafinil or armodafinil
[30:17] that are designed to
create wakefulness,
[30:18] they are all essentially
chemical variants
[30:23] of things that increase
epinephrine and dopamine.
[30:26] Now, of course, I'm
of the standpoint
[30:28] that things like
cocaine and amphetamine
[30:30] are just across the board bad.
[30:31] They have so many addictive
and terrible effects.
[30:34] In the proper setting prescribed
by the proper professional,
[30:38] things like modafinil for
narcolepsy might be appropriate.
[30:42] I know that a lot of people
out there take Adderall,
[30:46] even though they haven't been
prescribed Adderall in order
[30:49] to increase wakefulness.
[30:50] That is essentially, well,
it's illegal for one,
[30:54] but it's also abusing
the system in the sense
[30:57] that you're pushing back
on the adenosine system,
[30:59] slightly differently
than you do caffeine.
[31:01] It will make you
feel more alert.
[31:02] There tends to be
a heavy rebound
[31:04] and they do have an
addictive potential.
[31:05] There are also
some other effects
[31:07] of those that can be quite bad.
[31:08] But there are some
supplements and some things
[31:10] that are safer, certainly safer,
and that in cases where you're
[31:16] doing all the right behaviors,
you're exercising and eating
[31:19] correctly and you're
still having trouble
[31:21] with sleep, that can be
beneficial for falling
[31:24] and staying asleep.
[31:25] Now, I want to be very clear.
[31:26] I am not pushing supplements.
[31:28] I'm just pointing you
toward some things
[31:30] that have been shown in
peer reviewed studies
[31:32] to have some benefit.
[31:34] The first one is magnesium.
[31:37] There are many
forms of magnesium,
[31:38] but certain forms of magnesium
can have positive effects
[31:41] on sleepiness and the
ability to stay asleep,
[31:44] mainly by way of increasing
neurotransmitters, like GABA.
[31:48] There are a lot of forms
of magnesium out there,
[31:50] but one in particular
is magnesium threonate.
[31:53] T-H-R-E-O-N-A-T-E, which you
have to check to see if this is
[31:59] right for you.
[31:59] Check with your doctor.
[32:00] The other thing is theanine.
[32:02] T-H-E-A--
T-H-E-A-N-I-N-E. Theanine.
[32:09] 100 to 200 milligrams
of theanine for me
[32:12] also helps me turn off
my mind and fall asleep.
[32:15] Interestingly, theanine
is now being introduced
[32:17] to a lot of energy
drinks in order
[32:20] to take away the jitters
that are associated
[32:22] with drinking too much caffeine
or with some other things that
[32:24] are in the energy drinks.
[32:26] So just a consideration.
[32:28] Again, I'm not here
to tell you what
[32:29] to do or not do, but just want
to arm you with information.
[32:33] The thing about theanine and
magnesium is taken together,
[32:38] they do for some people,
they can make them so sleepy
[32:41] and sleep so deeply that they
actually have trouble waking up
[32:43] in the morning.
[32:44] So you have to play with
these things and titrate them
[32:46] if you decide to use them again,
if you decide to go this route,
[32:49] I would not start by
taking supplements.
[32:51] I would start by getting your
light viewing behavior correct.
[32:54] And then think
about your nutrition
[32:56] and then think
about your activity
[32:57] and then think about whether
or not you want to supplement.
[33:00] We already talked about
melatonin earlier.
[33:02] There's another supplement
that can be quite useful,
[33:04] which is apigenin.
[33:05] A-P-I-G-E-N-I-N, which is
the derivative of chamomile.
[33:09] 50 milligrams of apigenin
also can augment or support
[33:14] this kind of creation of a
sleepiness to help fall asleep
[33:18] and stay asleep.
[33:20] As an important point, apigenin
is a fairly potent estrogen
[33:24] inhibitor.
[33:25] So women who want to keep
their estrogen levels high
[33:28] or at whatever levels
they happen to be at
[33:31] should probably avoid
apigenin altogether.
[33:33] And men take that into
consideration as well.
[33:37] Men need estrogen also.
[33:38] You don't want to completely
eliminate your estrogen.
[33:40] That can create all
sorts of bad effects
[33:42] on libido and
cognition, etcetera.
[33:45] So apigenin in some
people is going
[33:47] to be a pretty strong
estrogen inhibitor.
[33:49] So keep that in mind.
[33:50] So thank you so much for
your time and attention.
[33:52] And above all, thank you for
your interest in science.
[33:54] [MUSIC PLAYING]