Sleep: Why You Need to Make it a Priority
Level 2: Rookie
Welcome Players! Sleep is the highest magnitude change you can make to improve your health almost immediately. It requires no resources, has no financial cost, and only requires your pointed attention to schedule. In order to operate at optimal efficiency both physically or mentally, sleep is absolutely necessary. Science has long proven the detrimental effects lack of sleep has on human performance: we will explore the research that highlights why you should stop sacrificing sleep and what will happen as a result if you do.
Cognitive effects of limited sleep
Risk management & decision making
Physical effects of limited sleep
How many hours is enough?
Time in bed
Thanks for reading Train Like a Pro! Subscribe for free to receive new posts and support my work.
Cognitive Effects of Limited Sleep
High-level cognitive function is dependent on adequate amounts of sleep. The process of learning is rooted in cycles of REM and NREM sleep, which act to rinse away non-essential memories and then solidify the necessary ones. This concept is highlighted extremely well in Matthew Walker’s book, Why We Sleep. Sleep is a requirement in order to learn anything effectively.
Learning a new language, becoming familiar with a new software / process, or motor skills that need repetitive exposures such as improving your golf shot accuracy or learning to put top-spin on a tennis ball. While most people think that the learning occurs during the act of practicing, this is not true. While practice is the vehicle through which we build up repeated memories of what we’re trying to learn, and the instant feedback of errors allow us to make micro-adjustments which over time lead to improvement, the act of learning itself actually occurs while we sleep.
Take two people, teach them the same thing over the course of one week, allow one person to sleep while not allowing the other to sleep and the person who had adequate sleep will test significantly better at the things they learned compared to the ones who didn’t.
Ok, so sleep is essential for learning new things. But can sleep really impact the ability for our brain to function? How does sleep affect critical thinking ability? Or risk-management decisions?
Risk Management & Decision Making
Take the Iowa Gambling Task, a protocol used to research the effects of decision making. Using multiple card decks, researchers asked participants to choose between:
A card deck that delivers occasional small gains with infrequent small losses.
A card decks that gives large gains with more frequent large losses.
The correct (and profitable) choice here would be the frequent small gains with little risk of small losses, yet sleep-deprived individuals chose the larger gains with frequent large losses, a high-risk and decidedly unprofitable option.
Sleep deprived individuals have also been shown, in gambling environments, to transition from avoiding loss and profiting to risk-seeking and eventual net losses. And if that’s not enough, their ability to learn from the negative consequences of risky behavior was blunted. They weren’t influenced as greatly by the impact of losing. Betting more in the hopes of winning more, losing, and then not learning and continuing the poor path.
To the investing and gambling personas out there, sound familiar??
Loss of sleep also affects how we interpret and evaluate decisions based on judgements instead of objective results. This study used social interaction games to test decisions based off of bargaining and trust. They found that participants who were sleep deprived turned down seemingly-unfair offers that would have resulted in a net-zero payoff, opting instead for the more-fair seeming option even though it meant less monetary gain. A poor financial decision for the sake of emotions.
Not only are our risk-management abilities hindered with a loss of sleep, but the perceptual impact of negative occurrences are greatly magnified in a sleep-reduced state. Meaning when bad things happen, we interpret them as being worse than we might have had we been well-rested. This compounds on our previous point. You make a poor decision and if that decision is realized in the same wake cycle, you take the negative feedback far more harshly. This can lead to a cascading effect. Ever have one of those days where something goes wrong and you just aren’t able to turn the day around? The day keeps getting worse and worse? When it rains, it pours, they say. Have you ever thought about if those days come after a night of poor sleep, either by choice or by circumstance? The two are likely related.
It should be obvious now the detrimental affects lack of sleep can have on risk-management behavior, but what about how our emotional state responds to limited Zzz’s?
This review of sleep loss and our socio-emotional responses is clear as day. To summarize,
“Sleep loss amplifies basic emotional reactivity, increasing negative mood states (e.g., anxiety, depression, suicidality), [and impairs] the accurate recognition and outward recognition of emotions. Inadequate sleep… increases social withdrawal, triggering marital and workplace conflict, and [weakens] leadership skills. The emotional dysfunction experienced by sleep-deprived individuals, such as loneliness or lack of work motivation, can be ‘transmitted’ to well-rested others who encounter an under-slept individual, reflecting viral contagion.”
The negative cognitive consequences that result from a loss of sleep are very clear. Choose to sacrifice sleep, and you’re also choosing1 to
seek out higher-risk opportunities
take on more risk unnecessarily
interpret negative feedback with greater magnitude
make yourself less likely to learn from negative feedback or mistakes
continue the behavior uninhibited for a cascading effect of consequences
More risk, more loss, greater emotional toll, and less likely ability to change. What could go wrong?!
Physical Effects of Limited Sleep
Let’s transition to the athletic edge of physical performance and the effects of sub-standard sleep opportunity, which are less obvious.
While you may thought I was setting you up to describe how sleep has enormous negative effects on physical performance, this actually is not the case.
The truth is that while there is no unified conclusion, most evidence available right now suggests that the ability for muscles to produce force, as well as productions of anaerobic power, muscular strength, total power output, and glycogen supply all remain relatively unaffected by nominal amounts of sleep loss.
In simpler terms, you can be just as fast, strong, and powerful with little-to-moderate sleep loss than fully rested. That is of course not true in a linear fashion, where there is most certainly a point where accumulated sleep-restriction or sleep-deprivation will lead to substantial negative impacts on performance, somewhere beginning around the 24h-36h mark depending on which variable is in discussion.
But being fast and strong aren’t the only factors when competing in a physical competition. Most, if not all, sports require some degree of coordination, skill, and decision-making. I’ll expand on that first point here with one of my absolute favorite studies, one that after I read fully I personally made a full commitment to prioritize sleep.
The title, “Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication.” aptly named, was published in 2000. Researchers found that being awake for ~16.9 – 18.5 hours results in reductions of cognitive and motor speed, accuracy, coordination, and attention equal to someone who has a Blood Alcohol Content (BAC) of 0.05%. When awake for ~17.7 through 19.6 hours, you’d be operating at an equivalence of a 0.1% BAC, which would deem you unfit (and illegal) to drive according to the United States federal government (limit .08%).
Performance decrements of -57% in reaction speed, -187% for reaction time, -31% in hand-eye coordination, -26% for visual tracking ability, and a 200% increase in false-alarms on a test of vigilance and concentration. No wonder drowsy drivers account for a large number of motor vehicle accidents, both commercially and industrial machine operators.
So while an athlete may be able to physically perform while lacking sleep, think weightlifting or powerlifting here, they will be quite significantly behind competitions that require any form of strategical decision, such as which receiver a quarterback should throw the ball depending on the defense’s coverage (remember the impact loss of sleep has on risk management?) or whether to go for the green in two or lay-up (risk-seeking behavior sound familiar?).
How can you apply this info to your life? Let’s say you’re in the red on sleep for the week, but you still want to maintain your exercise / training regiment. You can and should adapt your focus on expressions of physical strength, such as resistance training, instead of attempting to make progress on skill acquisition, such as refining your putting stroke. You will be much more efficient in terms of effort by conceding your mental deficit and doubling-down on your body’s muscular resilience.
You should now have a fairly good idea of how the human body responds when significantly underslept. I encourage you to spend some time reading the research articles and resources linked above, but for those who don’t, it’s imperative you understand the context all this information falls.
Better Sleep in Your Life
In what environment is all the above information true? How much sleep must you be below optimal before these effects are seen? Is it from completely abstaining from sleep (sleep deprivation) or simply limiting how many total sleep hours you get (sleep restriction). What about if your sleep is occasionally disrupted (sleep interruption) but you get an adequate total number of hours??
Before we dive into the answers, it must be explicitly stated how important understanding the context is to conversations involving health and performance. There is rarely, if ever, an absolute effect a health or wellness intervention will have regardless of scenario. The more you understand the context the information was gathered in, the more adaptable you’ll be when applying that information to your own life. It is for this very reason I restrain from providing blanket recommendations, as every individual will vary. No one solution can work for everybody. But there is one solution for every person. You just have to work to find it.
For starters, it is widely (and scientifically) accepted that we need between 7-9h of sleep. Now that’s quite a range, and justifiably so. The Sleep Foundation recommendations, along with physiological needs of sleep, vary depending on age. There are still a number of evidence-backed battles going on pushing back against the early wake-up calls required for the organized education of the youth, ie. school starting at 7am when teenagers are proven to have a naturally delayed circadian rhythm preventing them from falling asleep easily before 11pm. That is a topic for another day, although an important one to call attention too. For the purpose of our conversation, let’s continue on the assumption of a grown adult.
Where does that 7-9h, and often heard average of 8h recommendation come from?
There are incredible individual differences that influence how much sleep a person needs and combined with the fact that decline of function can be seen as early as only getting 7h of sleep multiple nights in a row, it’s fair to call 7h of sleep our upper limit. Put otherwise, the least amount of sleep you need before you start seeing declines in function would be ~7 hours. But this doesn’t make 7h of sleep optimal, far from it. Optimal is most often found in the range of 8-9h for adults, and that will depend on you, your body, and your environment.
The other fact to take into consideration is that time in bed does not equal sleep.
If you get into bed at 11pm and alarm goes off at 7a, you cannot expect to receive 8 hours of sleep.
You must consider the time it takes to fall asleep, as well as plan for occasional interruptions, either as part of your sleep process or due to external interference.
If your goal is 8h of sleep, and you know it takes you ~20 minutes to fall asleep and you tend to wake up 2-3 times per night for a few minutes each, then you should be anticipating being in bed 8.5 hours before you have to wake up to receive 8 hours of quality sleep.
I find that most people often overlook this simple element when planning their sleep routines. Don’t make that mistake.
So if I have one night where I’m not able to get adequate amounts of sleep, my next day is guaranteed to be $#!T? Not exactly. Fortunately for us our performance won’t fall off a cliff because of one bad night. We’re actually quite resilient to one night of sleep-restriction, but not sleep-deprivation. Pulling an all-nighter will absolutely limit your capacity to perform the next day, but one night of staying up late or waking up early won’t see such drastic negative influence.
Where most of our society faults is the extrapolation of our ability to buffer one night’s bad sleep with the assumed ability to fend off repeated bad night’s sleep. This is an dangerous assumption. For repeated nights sleep-restriction of even up to 1 hour loss (from optimal levels), this study found that 2 nights of consecutive sleep interruption has a greater disruption on mood and performance than 1 night of total sleep deprivation. So it’s bad to pull an all nighter, but it’s even worse to pull 2 late nights/early mornings back-to-back.
It gets worse from there, the more consecutive nights you prevent your body from getting its sweet sweet Zzz’s, the more you’ll continue to decline cognitively. Up to a certain point that is, leveling off somewhere around 5-14 days of sleep-restriction, where you are now operating at a new baseline of decreased performance.
Every time I hear someone say, “Yea, but I only need 4 hours of sleep and I’m good to go.” I immediately make a mental note to limit my time with that person. Not only is the percentage of the population that can function effectively on limited sleep extremely low, but the likelihood is that that person has been living below their optimal state for so long they genuinely believe they’re at their best when they only sleep that much. In either case, you don’t want to be around that person, and if you ARE that person, this (article & evidence supplied) is me pleading with you to change for the better.
You are now armed with a surplus of information that is actively ignored throughout society. You might be in a culture that rewards the “grind” mentality. Maybe it’s an office that brags about how little sleep they’re getting due to how much they have to do. Or maybe you’ve always neglected your sleep habits because you never knew how much a difference they made. You could be the person who’s been operating below optimal for so long you’ve established a chronic deficit and are accustomed to your new normal. This is your sign, you CAN change! And you should. If you’re in a position of power where you are responsible for finances, the livelihoods of others, or success hinges on quality mental performance, than you are doing a great disservice to your craft by depriving yourself of consistent quality sleep.
Now you may be thinking, OK. I get it. Getting enough sleep is important. I can afford an occasional night of limited sleep every now and then, but when it becomes extreme or consistently limited sleep I'll be at a significant disadvantage mentally and emotionally. I’ll be more likely to seek and take on averse risk, will be prone to making ill-advised risk management decisions, be less likely to learn from mistakes and feedback, will have a greater emotional experience to negative stimuli, and will inhibit my ability to learn new things. I’ll also be slower in cognitive performance tasks, such as driving or anything with hand-eye coordination, and be at a decisive disadvantage when competing against someone else strategically.
But how do I change?! I understand the difference between actual time spent asleep and being in bed, and accept that I’m going to need to carve out more time in order to reach optimal sleep, but how do I do that?
Change doesn’t start with a rulebook. It starts with you. It may sound corny, but in truth, you are a free-thinking, knowledgeable individual, and will be able to enact all the change that you dedicate yourself too.
You must first have a firm belief that sleep is valuable. And then you must emphasize the value you place on sleep with your actions and decisions. If your response here is, there aren’t enough hours in the day for me to be in bed 8.5-9 hours! Well, you’ve just said that whatever you do in those other 15-17 hours a day are all more important than how you think and feel on a daily basis.
With that said, here are two resources I’ve found beneficial in my own life that guided positive change as it relates to sleep.
The first is The Power of Habit, by Charles Duhigg. Your sleep routine is as much of a habit as your shower routine, and this book does an excellent job of breaking down the process to habit formation and how to replace bad habits with good ones. It will serve you well in your journey to a higher-functioning brain thanks to adequate sleep.
Next is a collection of content provided by Andrew Huberman, a neuroscientist and tenured Professor in the Department of Neurobiology at the Stanford University School of Medicine. His podcast and social media page is dense with knowledge on sleep, circadian rhythm, and the effects of light on both.
Why We Sleep, by Matthew Walker, as mentioned in the beginning of this article, is a thorough and exciting read covering all things essential to quality sleep.
I challenge you to evaluate whether you could be at a competitive or social disadvantage if suffering from performance declines due to sleep.
Executive at a large company? Your risk-management skills are of utmost importance when deciding how to move forward with faulty systems, difficult decisions, or new processes.
Human resources, personal relations, or hiring/firing? You will undoubtedly react with greater sensitivity to a candidates negative responses than their positive ones.
Involved in financial management of any kind? How about as an active investor, trader, or professional gambler? I hope the information on risk behavior and emotional reaction has spoken to you directly. It is no stretch at all to say that adequate amounts of sleep can improve your bottom line.
Compete in anything against another human? Professional sports? Collegiate or even high-school athletes? Your lack of sleep will leave you at a disadvantage when it comes to strategically gameplay that your opponent will most certainly take advantage of.
Startup founder, employee, or entrepreneur? Your strengths lie in your ability to critically think, of which you will be delayed in the speed and accuracy of decision-making. Your performance increases won’t be noticeable on paper as dealing a critical blow. It will be much more subtle, death from a thousand pokes, where you bleed out slowly from poor decisions and unstable risk.
The good news is that you can prevent all of this by simply prioritizing sleep. Do not give up those sweet sweet Zzz’s. Don’t trust me, trust the information. Stop sacrificing long term health and performance for short term completion of tasks.
There are many things involving sleep that we did not cover today, so please check out the resources I’ve advised. They will fill in many of the gaps of the information you seek, specifically relating to optimal environment of sleep, strategies to improve quality of sleep, and adjusting sleep/circadian rhythm according to unique schedules.
Future articles on sleep expanding upon this one will include strategies to optimize your sleep routine, best conditions to be in for quality sleep, things to try, and how to handle unique situations. Have a question, topic suggestion, or want to share your experience? Comment at the end of this article!
Sleep well my friends.
Note: loss of sleep due to internal conditions or external factors are obviously not at fault here. It is only meant to encourage those who willingly avoid adequate sleep to reconsider.