In 1959, a well known radio personality named Peter Tripp staged an experiment in New York City’s Central Park where he endeavored to stay awake for 200 hours. He barely succeeded, experiencing hallucinations of spiders and mice, becoming hostile, incomprehensible, and eventually falling asleep for thirteen hours. Reports of his life afterwards are of a man who experienced regular episodes of psychosis and who subsequently lost his marriage and his work.
Six years later, a seventeen year old high-school student from San Diego named Randy Gardner set out to break Tripp’s record and succeeded at staying awake for 264 hours. He experienced confusion, hallucinations (thinking a street sign was a person), and an inability to focus on simple cognitive tasks like "serial sevens" – (this is a test that involves subtracting the number seven from one-hundred repeatedly, i.e. 100 → 93 → 86 and so on). He made it to sixty-five before suddenly stopping because he forgot what he was doing. At the end of the experiment, he slept for fifteen hours and awoke feeling back to his normal self. He attended school the next day.
In 2005, Mike Trevino, a well known endurance athlete, competed in the Race Across America. In this race, athletes attempt to cross the country by road bicycle as quickly as possible. In order to win, athletes have learned to operate on a bare-minimum of sleep, perhaps only one to two hours at a time. Mike completed the race in eight days racking up a cumulative sleep time between ten and eleven hours for the whole eight day period. In his interview on Peter Attia’s podcast, Mike describes the process.
He explains that he tries to sleep for a single REM (rapid eye movement) sleep cycle and wake up immediately at the end of the REM cycle. The typical duration from onset of sleep to completion of the first REM cycle is roughly one-hundred minutes (Gillberg and Åkerstedt 1991). To time this perfectly, he learned from another athlete to have his wife watch his eye movements while he slept and to wake him up as soon as they stop moving. The idea is to wake up just at the end of REM sleep, when sleep is the lightest. This allows you to feel reasonably awake, whereas awakening in the middle of deep slow-wave sleep results in feeling groggy.
In this particular year (I am not sure if it was 2004 or 2005), he had slept less than two hours by day six or seven of the race. He says this in reference to his support team who followed him in a van,
I thought they were spies. I was truly delusional, and I was paranoid. I would try to get away from them, and I kept racing away from them, and they’re still following me, and they’re turning where I’m turning…and finally I decided to get off the highway, and I’m in a cemetery in the middle of nowhere and I hold up my bike, it’s all I had to protect myself, in between me and my crew, and they followed me…this van is here and they get out, and I’m like what are you doing?
The cognitive dysfunction is severe and obvious in such marked cases of sleep deprivation, but the sleep research literature is filled with studies of memory, cognition, and reaction time studies on much milder sleep deprivation. Consider for instance studies demonstrating delayed reaction times and inappropriate line-crossings in drivers who slept only two hours versus eight hours (Coco et al. 2019). There is certainly inter-individual variability in the response to sleep deprivation, but it’s incontrovertible that obtaining adequate sleep is essential.
Many sleep experts emphasize the cruciality of adequate sleep. Matthew Walker, author of the book Why We Sleep (which is on my short list of books to read), wrote the following in his book:
Ten days of six hours of sleep a night [is all it takes] to become as impaired in performance as going without sleep for twenty-four hours straight.
In the Northern Hemisphere, the switch to daylight savings time in March results in most people losing an hour of sleep opportunity. Should you tabulate millions of daily hospital records, as researchers have done, you discover that this seemingly trivial sleep reduction comes with a frightening spike in heart attacks the following day. Impressively, it works both ways. In the autumn within the Northern Hemisphere, when the clocks move forward and we gain an hour of sleep opportunity time, rates of heart attacks plummet the day after. A similar rise-and-fall relationship can be seen with the number of traffic accidents, proving that the brain, by way of attention lapses and microsleeps, is just as sensitive as the heart to very small perturbations of sleep. Most people think nothing of losing an hour of sleep for a single night, believing it to be trivial and inconsequential. It is anything but.
While it’s true that some people require seven or eight hours per night, it seems similarly true that others require only six, and yet others require nine. It’s also been proposed that the detrimental effects from lost sleep cannot be mitigated by increased sleep on subsequent nights. There are good reasons that experts believe this to be true, but I think it’s hard to demonstrate on an individual basis.
After listening to sleep experts talk about the short and long-term effects of chronic sleep deprivation, I attempted for months to engineer, monitor, and optimize my sleep. But, this approach caused other problems because it leaves out the full context of sleep. Sleep and its benefits are clearly valuable, but they must be compared to other values in my life, all of which require me to be awake. For instance, my once rigid and zealous approach to sleep limited my ability to work late at night when I am sometimes most motivated and focused. It’s easy to become obsessed with sleep to the point of being afraid to get into bed thirty minutes later than normal, or to get up earlier or later than usual out of fear of disturbing my circadian rhythm. But, this sort of rigidity, can cause so-called "sleep anxiety," which itself can lead to limited and fragmented sleep. I think most people can identify the feeling of knowing they need to get to sleep, but being unable to do so.
I believe the answer to all of this is to have a specific, yet contextual and adaptable plan. So, I’ve attempted below to go over what I think are the most impactful ideas that I’ve used to help optimize my sleep within the full context of life.
Live Soundly, Sleep Soundly
More than anything else, I think that what I do while I’m awake determines how well I sleep. I think that those who sleep most soundly, are those who live most soundly. I believe that living soundly means living with purpose and integrity; with values and with moral consistency. In order to do this, it’s necessary for me to choose, rank, and pursue my values every day. This is hard work. If I manage to do this successfully for a full day, I’m tired and satisfied at the end of the day. After a day like this, I can sleep on the floor, with an empty stomach, in eighty-five degrees, in my work clothes. In contrast, when I fail to pursue my values, or worse, if I act against my values, I don’t feel tired; instead I feel anxious, stressed, and restless. I can’t sleep even in perfect conditions. For instance, some days I set a list of tasks that I want to complete, but I decide instead to browse social media under the guise of "networking." I know very well that I’m not doing my work, and at the end of the day, instead of wanting to sleep, I feel the need to stay awake either to finish the work I didn’t do, or subconsciously to punish myself for failing to do what I know I should have done.
Besides the mental and physical exhaustion that results from hard work, I’m able to judge myself as having earned my rest when I’ve done what I set out to do. When I lie down in a dark quiet room, instead of my subconscious mind generating the restlessness that comes from regret, I instead feel relaxed and serene because I’ve pursued my values.
To prove this theory to myself, I performed a thought experiment, or more accurately, I thought back to arguably the most stressful time period of my life — medical residency. During this three year period, I was under constant stress, I ate poorly, my exercise was lacking, I drank ample caffeine at all hours of the day and night, I switched constantly from day shifts to night shifts, I followed almost zero conventional sleep recommendations, and yet I slept soundly wherever and whenever I wanted. Perhaps this was in part due to sheer physical and mental exhaustion, but that can’t account for the whole of it. In fact, I had some rotations during which there was ample time to sleep and I was not exhausted, but I slept well nonetheless because I was working hard at something I loved.
There was one brief period during which my sleep suffered, and predictably, this was a period of weeks during which I was very disappointed in my own clinical performance. During this period of fragmented sleep, I was actually on one of the most difficult rotations that allowed me the least possible time for sleep, and so I was the most exhausted I could have been, and yet I couldn’t sleep. As soon as I resolved the psychological distress, sound sleep returned.
I don’t believe that there are any sleep hacks, supplements, medications, or blue-blockers that will overcome a mind at war with itself. Prescription strength sedatives and alcohol can render you stuporous, but not only does this fail to induce restful sleep (Garcia and Salloum 2015), it obviously contributes to the cycle of value destruction and regret that prevented sleep in the first place.
I asked several friends and colleagues for their thoughts on these ideas. Each agreed to some extent, but had many interesting points of their own. Here is what they said:
Dr. Michael Garrett, owner and physician of Direct MD Austin, TX (Website & Facebook Page), said
I think you are probably onto something with the mental aspect and an un-integrated mind. But I have not given it a lot of thought, frankly. I would say that a lot of patients I see with insomnia issues have anxiety, and then sleep anxiety, which is a self-perpetuating problem. (There’s a lot of "I’m only going to get 5 hours, I’m only going to get 4 hours" type thoughts, and they often seem to set neural patterns of those anxious thought pathways, which reinforces the problem.) I suspect that you are onto something that if they do not have enough purposeful activity or organizing principles for their life, that contributes to or exacerbates the problem.
I will say that the most effective thing, by far, for my patients has been finding a good CBT-I therapist. (Cognitive Behavioral Therapy for Insomnia.) I found one here locally (Austin, TX), Dr. Chelsea Vaughn PhD. Her assistance has been life-changing for several of my patients with long term sleep problems. It’s 6-8 therapy sessions, as well as some homework (sleep diary, etc.) and sleep restriction. It works absolute wonders and has helped me get several people off of sleeping medications for the first time in years or decades.
Jason Crawford is a former software engineer and now expert and pioneer of a growing intellectual movement called progress studies. He writes for his blog rootsofprogress.org. He replied,
I’m sure that psychological problems that cause stress/anxiety can interfere with sleep. But there can be all sorts of things, not every sleep problem is psychological.
I used to have a lot of trouble getting to sleep. In early 2013 I did some research, made a list of all the things that people said might help, and experimented with them. It turned out that what I was most sensitive to was light. Keeping the lights in the apartment on brightly right up until bedtime, and using computer screens, was keeping me up. (Also, I was in an apartment that had a street light shining through the window.) I started using the dimmer switch on the light in the evening, and I got an app called F.lux for my laptop that turns the screen orange in the evening to avoid blue light. I use a similar feature on my iPhone and Kindle now. I also got a sunrise alarm clock that wakes me in the morning using light. And I got blackout curtains to block the street lamp at night. I experimented with those orange glasses (blue light blocking glasses), too, but they’re bulky and uncomfortable and if I do those other things I don’t need them.
That plus don’t have caffeine in the evening, pretty much does it for me. Other things didn’t seem to be so important, like temperature of the room, etc.
All that said, I have had times in my life/career when I was anxious and stressed from things going on in life/work. On some occasions that has made it hard to sleep. It wasn’t about an integrated mind exactly, nor was it about not doing enough during the day. It was about an ongoing difficult situation. I need to deliberately stop thinking about it in those cases. It can be hard because I have a certain sense of responsibility: if there’s an important problem it feels irresponsible to stop thinking about it! In those cases I remind myself that I’m not going to solve the problem or even really make progress while I’m lying in bed going to sleep. Therefore it doesn’t help to think about it, and therefore it’s not irresponsible to stop thinking about it. In fact, the responsible thing to do is to stop thinking about it so I can get to sleep and tackle the problem the next day well-rested.
A friend of mine, Joe England, MD, a neuro-radiologist who works seven consecutive night-shifts for every fourteen day period, had this to say:
I think having daily actions integrated with your values is probably an important condition but I’m not sure that it is the crucial issue that stops most people from sleeping well. For me, making sure I’m tired at night is the most important thing (so — less coffee, more exercise, not sleeping in, less screen time before bed). Also, being outdoors at night before bed helps. If I sit on my patio with very low light and read a book, I get more tired for bed. I think my subconscious mind better appreciates that it is night time.
These people have spent a lot of time dealing with sleep on a personal level, and in Dr. Garrett’s case, as a physician helping treat patients with disordered sleep. Their answers are a good segue for the sections that follow, each of which discusses a technique or variable that can affect sleep.
For me, this is the single most impactful activity that has made it easier for me to get to sleep. Unless I am completely exhausted, I have to shut-down my day and make a plan for the next day. Not only does this give me a quiet mind when I hit the pillow, it also sets me up to feel motivated when I wake up in the morning.
This process starts by getting as much done during the day as possible, and whatever is left undone at the end of the day gets scheduled for a specific time in the future.
If I have tasks left over in the evening, I solve this problem by journaling, checking on my short, medium, and long term goals, and reorganizing my task lists to prepare for the next day. This activity allows my subconscious to relax. I was inspired to do this consistently after reading Cal Newport’s book Deep Work. In the book, he talks about doing a "shut-down" routine at the end of the work-day, akin to shutting down your computer. I believe he even advocates coming up with a phrase that you say to yourself when the shut-down is complete, to make it very clear to both your conscious and sub-conscious mind that you are done working for the day. For example, you could say to yourself, "shut-down complete."
This tactic gives you a clear stopping point for work, problem solving, and worrying, and grants you permission to relax in whatever way you see fit.
Having a consistent sleep schedule will establish a routine, a pattern, and habits surrounding sleeping and waking that your mind and body will grow accustomed to. The strongest zeitgeber (literally time-giver – or signal to the brain that indicates the time of day), and strongest means of entraining the circadian rhythm, is probably light (addressed in more depth below). Thus, if it’s possible to wake with sunrise and sleep just after sunset, I think this is likely optimal for most people. However, it is important to note that different people have different chronotypes; that is, some people have a predisposition to waking earlier and going to sleep earlier whereas others might naturally wake later and stay up later. And, in addition, an individual tends to have shifts in chronotype throughout their life-time (typically earlier as infants and young children, later as adolescents, earlier again as adults, and still earlier in the elderly).
According to some sleep experts, the most important aspect of sleep scheduling is consistent awakening time. Awakening at a consistent time, and especially when accompanied by blue-light exposure from the rising sun, or from artificial blue-light sources if necessary, will help maintain a consistent circadian rhythm that is self-perpetuating if kept consistent. It’s easy to disturb this rhythm with just one or two nights of staying up too late and then sleeping in. If you have to stay up late, it may be better to awaken at the usual time with less sleep, than to sleep in. The extra time sleeping-in feels good in the short-run, but it usually leads to staying up later and later on successive nights. Then, invariably, when the need arises for early awakening once again, it’s difficult to obtain adequate sleep. Many people, myself included, experience this on a weekly basis due to so-called "social jet-lag." This is the phenomenon of staying up late on weekend nights, sleeping in on weekend days, and then being forced to wake up early for work on Monday morning.
I personally have difficulty keeping a consistent sleep schedule due to the nature of my work, which has a constantly variable shift-based schedule, but when possible, I stick to the advice above.
Having a routine to deliver bedtime cues to your subconscious can be useful. As I indicated above, I think the most useful preparation for bed is the mental preparation of cognitive off-loading.
Some other examples include stretching, reading, listening to a podcast (my favorite podcast) or audiobook (I use audible), or taking a hot shower. Just make sure the activity doesn’t conflict with the other recommendations (e.g. starting a new project, eating, or exercising vigorously just before bed). I usually listen to a podcast with the sleep timer set to 15 or 30 minutes. Sometimes I do mobility work with a foam roller or a mobility "peanut" if I feel physically tense. I use TheReadyState.com to help guide my mobility work (members of my practice have complementary access).
Other people find meditation, saunas, baths, hot showers, and countless other rituals to be helpful. I think it’s likely that some rituals are better than others on the average, but what is probably more important than finding the one best ritual, is having your own process for relaxing and signaling to your mind that it’s time to sleep.
Sleep experts recommend total darkness in the bedroom while sleeping and they recommend eliminating blue-light exposure in the late-afternoon and evening. Blue-light delays the secretion of melatonin from the pineal gland, which is the primary neuro-hormonal signal for sleep initiation.
I aim for darkness in the bedroom, but I do have a couple very dim LEDs and some outside light that filters into the room that don’t seem to bother me–it’s possible that they are limiting my sleep, and I have noticed that total darkness does seem to produce the most restful uninterrupted sleep, at least subjectively.
I do use night shift mode on my Apple devices in the evening, which cuts the blue light out of the screen. I also dim these devices as low as they’ll go after sundown. For non-Apple devices, there are often similar settings built in, or you can use an application called f.lux. I dim my house lights to minimal brightness and use as few lights as necessary.
Some people really go all out by installing red-spectrum lights in their house and wearing blue-blocking glasses in the afternoon or evening. I’ve never tried this, but if you have a real problem getting to sleep, this might be worth looking into. Peter Attia, MD, one of my favorite resources on sleep, nutrition, and longevity medicine discusses this at length in multiple places on his website and podcast. In July, 2020, he recommended these glasses from a company called Felix Gray. I have not tried them myself.
Cooling of the core body temperature may help with sleep initiation. And, typically, staying cool throughout the night will promote slow-wave sleep, whereas warming up will promote wakefulness. In fact, I like to take a hot shower before bed and get into a bed that’s been cooled by low ambient temperatures. This usually helps me initiate sleep. I then like for my house to warm up in the morning to help me awaken. This mimics the environmental conditions of sleeping outside, where it’s likely that people who sleep outside would awaken just before sunrise by an increase in temperature.
I sleep at 71 or 72 degrees in the summer on most nights, and in the winter I heat my house to around 65 degrees. I adjust my clothing until I feel comfortable. I try to keep my house as cool as I can tolerate in the winter and as warm as I can tolerate in the summer. I adjust only enough to make it comfortable to work and to sleep. The reason for this is to also acclimatize to outside temperatures. I have found that sleeping in warmer temperatures in the summer has helped me feel more comfortable outside in hot temperatures. If I sleep at temperatures consistently cooler than 72, I feel uncomfortable outdoors on hot summer days. The converse is true in the winter.
There is probably a good balance here that can be found on a case-by-case basis. Overall, if you’re having trouble getting to sleep and you’re also over-heated, cooling the house by a degree or two might be a good step to take. For those who have serious problems overheating at night and need drastically cooler temperatures than their bed-fellow, a personal cooling pad such as the Ooler or chiliPAD may prove useful. I haven’t yet tried either one.
Nutrition – Food Timing
I try to stop eating at least three hours before bed. I think this is helpful for most people, but it is essential for those who suffer from acid reflux. If you need to eat closer to bed time, keep it down to small items and consider minimizing protein consumption. Protein, of the three macronutrients (protein, fat, and carbohydrates) are more "metabolically expensive" to absorb and digest in comparison to fat and carbohydrate. Eating protein generates more heat (the thermic effect of food), may increase the heart rate, and may leave your stomach full for a longer period of time — all other variables being equal.
A personal favorite evening food is a cup of bone broth. It’ll take away hunger and may even help with sleep due to its glycine content (Kawai et al. 2015).
I’ve measured my own blood sugar, sleep latency, heart rate, heart rate variability, and sleep disruptions after eating large mixed meals (fat, carbohydrates, and protein) just before bedtime, and there is a major negative effect. My blood sugar stays elevated all night, my heart rate can run 10 beats higher than baseline, my heart rate variability plummets, and I can lose an additional 20-30 minutes of sleep over the course of the night in disruptions. There are several other reasons (Lopez-Minguez et al. 2019) not to eat close to bedtime that are outside the scope of this article.
I have tried to eliminate caffeine almost completely from my diet. When I do choose to drink coffee (which I love), I consume as little as possible and as early as possible in the day.
There are many factors that cause inter-individual differences (Nehlig 2018) in the metabolism and response to caffeine. Some people metabolize caffeine more slowly than others, and may still have some circulating caffeine late at night even after a single morning or midday coffee. The average person who drinks a fully caffeinated cup of coffee may still have one-third, or one-quarter of the caffeine from that coffee in their system eight hours after consumption. This figure doesn’t even include the metabolism of active caffeine metabolites (e.g. paraxanthine) that can also impact the ability to sleep. To complicate matters, there are genetic factors that determine whether a person will have affected sleep as a result of caffeine consumption.
It’s possible to feel normal, but to have delayed sleep from caffeine. If you have sleep troubles, it may be worth weaning off of caffeine and eventually eliminating it, at least temporarily, to see if this has a positive impact. If you do drink caffeine, and you think there is a chance that caffeine is impacting your sleep, you can try to stop drinking coffee (and other sources of caffeine) as early in the day as possible as an initial intervention.
It’s important to note that some people will feel fatigued, un-motivated, and may have severe headaches from caffeine withdrawal. Quitting can be difficult, but for some people may be worth the pain. If the symptoms are tolerable, my suggestion would be to push through them. If they are not, then a wean might need to be prescribed. When I was in the habit of consuming caffeine daily, if I skipped a day, I felt devoid of energy and motivation. But, two or three days later, I felt completely normal, and quite happy that I was no longer dependent on this substance. I am lucky in the sense that my only withdrawal symptom was feeling tired and un-motivated.
I think there is no doubt that, in general, exercise is an extremely important ingredient in every aspect of health and well-being, and sleep is no exception (Kovacevic et al. 2018). However, it’s possible that very intense exercise, certain combinations of exercise, and poorly timed exercise could be neutral or detrimental to sleep. "Exercise" is not just one thing – it is a term that obviously encompasses a wide array of activities. So, it’s possible, for example, that someone who has excess adipose tissue and who has not previously exercised, may have drastically improved sleep after initiating, for example, a program of walking for thirty minutes and performing resistance training (e.g. weight lifting) for thirty minutes per day. On the other hand, an otherwise healthy and lean individual who already performs a similar exercise program, may have no sleep improvement, or even a detrimental effect on sleep, by increasing the duration or intensity of their exercise program (Myllymäki et al. 2011).
If I had to generalize, I would say that most people would probably have improved sleep quantity and quality, and faster sleep onset, as a result of increasing the frequency, duration, and perhaps intensity of exercise. But, this is only because there are many people who do not exercise, or exercise very little. For individuals who exercise vigorously, for prolonged durations, daily, or even twice or thrice daily, the question can become more nuanced.
For several reasons, I have reduced the intensity of my exercise over the past several years, and instead try to perform only one or two high-intensity exercises per week. Those exercises are usually scheduled for morning or mid-day to minimize the effect they’ll have on my sleep.
Overall, I think it’s worth paying attention to sleep and the activities, or lack thereof, that might promote or reduce the ability to obtain restful sleep. For me, the most impactful strategies are: focusing on maximizing my values when I’m awake, having a clear stopping point to my work in the evening, obtaining the right type of light exposure at the right times, maintaining a consistent physical training program of mostly light-to-moderate exercise, and reducing/eliminating caffeine consumption. If I focus on obtaining high-quality and a proper quantity of sleep most of the time, I don’t stress too much if I miss out on sleep on occasion.
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