summarize: Once you have ruled out (or addressed) serious problems like sleep apnea,
there are concrete steps that you can take to improve your sleep, or at least
improve your chances of getting good sleep.
Most important, you must create an environment for yourself that is
conducive to sleeping well. The first requirement for good sleep is darkness.
Light is the enemy of sleep, full stop. Thus, you want to make your bedroom
itself as dark as possible—installing room-darkening curtains if you live
somewhere with a lot of outdoor evening light, and removing all light sources
in the bedroom, even down to electronic equipment like TVs and cable boxes
and such. Their little pinpoint LEDs are more than bright enough to keep you
from sleeping well. Digital clocks are especially deadly, not only because of
their bright numerals but also because if you wake up and see that it’s
3:31 a.m., you might start worrying about your 7 a.m. flight and never fall
back asleep.
This is easier said than done, because it essentially amounts to evicting the
twenty-first century from your bedroom. Modern life almost systematically
destroys our ability to sleep properly, beginning with the ubiquity of electric
light. Not only does non-natural lighting interfere with our natural circadian
rhythm, but it also blocks the release of melatonin, the darkness-activated
hormone that tells our brain that it is time to fall asleep. It’s similar to the way
that the SAD interferes with satiety hormones that normally tell us that we
are full and we can stop eating.
Even worse is the relatively recent advent of LED household lighting,
which is predominantly on the blue end of the spectrum, meaning it more
resembles daylight. When our brain detects that blue light, it thinks it is
daytime and that we should be awake, so it tries to block us from falling
asleep. Therefore, you should also reduce the amount of bright, LED light
that you’re exposed to in the evening. A couple of hours before you go to bed,
begin turning off unnecessary lights in your house, gradually reducing your
light exposure from there. Also, try to swap out blue-intensive LED bulbs for
those on the warmer end of the spectrum.
The devices we stare at before bed—phones, laptops, video games—are
even worse for our sleep. Not only do they bombard us with more blue light,
but they also activate our minds in ways that impede our ability to sleep. One
large-scale survey found that the more interactive devices subjects used
during the hour before bedtime, the more difficulties they had falling asleep
and staying asleep—whereas passive devices such as TV, electronic music
players, and, best of all, books were less likely to be associated with poor
sleep. This may partially explain why watching TV before bed does not seem
to affect sleep quite as negatively as playing video games or scrolling social
media does, according to research by Michael Gradisar, a sleep researcher
and professor of psychology at Flinders University in Australia.
I am increasingly persuaded that our 24-7 addiction to screens and social
media is perhaps our most destructive habit, not only to our ability to sleep
but to our mental health in general. So I banish those from my evenings (or at
least, I try to). Turn off the computer and put away your phone at least an
hour before bedtime. Do NOT bring your laptop or phone into bed with you.
Another very important environmental factor is temperature. Many
people associate sleep with warmth, but in fact the opposite is true: One of
the signal events as we are falling asleep is that our body temperature drops
by about one degree Celsius. To help that happen, try to keep your bedroom
cool—around sixty-five degrees Fahrenheit seems to be optimal. A warm
bath before bed may actually help with this process, not only because the bath
itself is relaxing but also because when we get out of the bath and climb into
our cool bed, our core temperature drops, which signals to our brain that it is
time to fall asleep. (There are also a variety of cooling mattresses and
mattress toppers out there that could help people who like to sleep cool.)
Our internal “environment” is just as important to good sleep. The first
thing I tell my patients who are having difficulty sleeping is to cut back on
alcohol—or better yet, give it up entirely. It’s counterintuitive, because
alcohol initially acts as a sedative, so it can help us fall asleep more quickly.
But as the night wears on, alcohol turns from friend of sleep to foe, as it is
metabolized into chemicals that impair our ability to sleep. Depending on
how much we’ve had to drink, during the second half of the night we may
have a harder time entering REM sleep and be more prone to waking up and
lingering in unproductive light sleep.
The effects of alcohol on memory and cognition are apparent even in
moderate drinkers. Studies have found that young people who drink heavily
are more likely to forget even basic tasks like locking the door or mailing a
letter. Students who averaged nine drinks per week (not much, by collegiate
standards) performed worse on a word-based memory test. And, in a finding
that will surprise no one, students who drank more slept later and felt sleepier
in the daytime, as well as performing worse on tests. More alarming is the
finding that students who drank heavily two days after a bout of learning or
study forgot or failed to retain most of what they had learned.
Note that these are all findings in young people, students who are
presumably at their cognitive peak. If you extrapolate to those of us in middle
and older age, who may have a lower tolerance for alcohol and a greater
propensity to forget things, the implications are worrisome. I find that my
own threshold is two drinks in an evening: any more than that, my sleep goes
sideways, and my work performance suffers the next day, no matter how
much coffee I drink.
Coffee is not a solution to the problem of poor sleep, especially if
consumed to excess or (especially) at the wrong time. Most people think of
caffeine as a stimulant that somehow gives us energy, but actually it functions
more as a sleep blocker. It works by inhibiting the receptor for a chemical
called adenosine, which normally helps us go to sleep every night. Over the
course of the day, adenosine builds up in our brain, creating what scientists
call “sleep pressure,” or the drive to sleep. We may be tired and needing
sleep, but if we ingest caffeine it effectively takes the phone off the hook, so
our brain never gets the message.
This is obviously helpful in the morning, particularly if our “chronotype”
is telling us we should still be asleep at 6 a.m. But the half-life of caffeine in
the body is up to six hours, so if we drink a cup of coffee at noon, we will still
have half a cup’s worth of caffeine in our system at 6 p.m. Now multiply this
by the number of cups of coffee you drink in a day and work forward from
the time of your last cup. If you down one last double espresso at 3 p.m., you
will still have a full shot’s worth of caffeine in your system at 9. What you
won’t have, most likely, is much of an urge to fall asleep anytime soon.
Everyone differs in their caffeine tolerance, based on genes and other
factors (23andMe tests for one common caffeine-related gene). I’m a very fast
metabolizer, so I can handle that afternoon espresso without it affecting my
sleep too much; I can even drink coffee after dinner, and it seems to have no
impact (unlike alcohol). Someone who metabolizes caffeine slowly should
probably stop at one or two cups, before noon.
This concept of sleep pressure, our need or desire for sleep, is key to many
of our sleep tactics. We want to cultivate sleep pressure, but in the right
amounts, at the right times—not too much, not too little, and not too soon.
This is why one of the primary techniques that doctors use to treat patients
with insomnia is actually sleep restriction, limiting the hours when they are
“allowed” to sleep to six, or less. This basically makes them tired enough that
they fall asleep more easily at the end of the day, and (hopefully) their normal
sleep cycle is restored. Their sleep pressure builds up to the point where it
overwhelms whatever is causing their insomnia. But this also helps explain
why napping can be counterproductive. Taking a nap during the day, while
sometimes tempting, can also relieve too much of that sleep pressure, making
it harder to fall back asleep at night.
Another way to help cultivate sleep pressure is via exercise, particularly
sustained endurance exercise (e.g., zone 2), ideally not within two or three
hours of bedtime. My patients often find that a thirty-minute zone 2 session
can do wonders for their ability to fall asleep. Even better is exercise that
entails some exposure to sunlight (i.e., outdoors). While blue light late in the
evening can interfere with sleep, a half-hour dose of strong daylight, during
the day, helps keep our circadian cycle on track, setting us up for a good night
of sleep.
It is also important to mentally prepare ourselves for sleeping. For me,
this means avoiding anything that might create stress or anxiety, such as
reading work emails or especially checking the news. This activates the
sympathetic nervous system (the fight-or-flight one) at a time when we want
to be destressing and generally winding down. I have to force myself to step
away from the computer in the evening; that queue of emails will still be
there in the morning. If there’s a burning issue that I can’t get off my mind,
I’ll write a few lines about it, creating a plan of action for the next morning.
Another way to turn down the sympathetic nervous system and prepare the
brain for sleep is through meditation. There are several very good apps that
can help with guided meditations, including some that are focused entirely on
sleep.
The overarching point here is that a good night of sleep may depend in
part on a good day of wakefulness: one that includes exercise, some outdoor
time, sensible eating (no late-night snacking), minimal to no alcohol, proper
management of stress, and knowing where to set boundaries around work and
other life stressors.