Rethinking Sleep from First Principles

If you’re like me, you’ve maybe had a love/hate relationship with sleep. As a life-long chronic insomniac, I’d love to sleep, but it’s never really been a thing for me. I went down the usual path of trying to get 8 hours of sleep, but even when I did, I didn’t feel any more refreshed than when I slept for 5 hours. Often, I actually felt better on 5 hours of sleep.

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One sleepless night, I thought “I didn’t care if I slept, I just didn’t want to be tired anymore”, and that thought led me to do a deep dive into the latest in sleep science, but what I found was disappointing. Mostly, just the same old sleep hygiene recommendations I’d heard when I was a kid. There has to be more to it! How have people been struggling with sleep for decades and the best we can come up with is “get more sleep”?

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It took me a LONG time to break out of the idea that more sleep time meant better sleep. The 8 hour rule has been beaten into us. It’s a myth that refuses to die. 

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So I thought I’d back up and take a look at sleep from a first principles approach. As much as I can anyway. There is still so much we don’t know about sleep, but what we do know, I believe, leads us to a very different path than the one the sleep industry follows, and refuses to give up on.

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Every animal with a brain has to sleep. It’s been said that there is no way that evolution would have kept sleep as a requirement if it wasn’t absolutely vital to life. For many animals it’s just too dangerous to lose consciousness for an extended period of time. For example, dolphins would drown if they didn’t come up for air, so they sleep with only ½ of their brain at a time. Other animals would become easy prey if they slept, so they only have a very short sleep opportunity. Lions, being the top of the food chain, have little concern for when and how they sleep, and evolution has left them with regular naps throughout the day.

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But right there we see the problem. Even I’m referring to sleep by time, when I’m trying to look from a first principles perspective.

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For a long time, weight was treated as a primary indicator of health. Not because it was the best measure, but because it was easy to collect, and generally useful at identifying outliers. If someone was severely underweight or morbidly obese, you could safely assume there was a health issue.

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But for most people, weight alone doesn’t say much. It doesn’t tell you how someone feels, how well their body is functioning, or how their systems are holding up over time. It doesn’t tell you about stress, recovery, immune function, or resilience.

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We’ve been measuring it by time, not because time is the right variable, but because it’s the one we can see. And like weight, it tells us something at the extremes. But for most people, minutes asleep isn’t what determines how well sleep is working.

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The primary restorative function of sleep is deep sleep, or slow-wave sleep, which again, is often measured by time, but slow-wave sleep isn’t time based. A slow-wave is the synchronous firing of neurons which are the foundation of health. This precise brain activity is part of the vital restorative processes that occur during sleep, and slow-waves in particular are tied to the flushing of metabolic waste from the brain, they kick-off a cascade of hormonal responses, they prime the immune system, and it is a time when memories are encoded and stored. 

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Deep sleep can be very restorative, if your neurons are firing well, and those processes complete successfully, it’s hugely valuable sleep. However, the same “deep sleep” can just as easily have less functional restoration, with lower delta power, when the brain is less capable of repair. You’ve likely felt this after drinking alcohol. You may have had deep sleep, but the restorative function was impaired. As we age, the effectiveness of slow-wave repair declines even if we’re getting an appropriate amount of “time” in deep sleep.

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Spindle activity is another process tied to memory. These are short bursts of brain activity that seem to help transfer memories into long-term storage. The more spindles you have, the better your memory consolidation tends to be. And unlike deep sleep, we don’t measure this by time. You don’t track minutes of spindles. You count them like dollar bills, not minutes in a bank account.

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K-complexes are large electrical bursts that seem to help your brain stay asleep while still monitoring your environment. They often occur when there’s noise or movement nearby, acting like a gatekeeper. Most of the time, the brain hears something and says, “that’s not important, keep sleeping.” But sometimes, especially in light sleepers, k-complexes are followed by waking. It’s the brain deciding it needs to bring you back to awareness.

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REM sleep plays a key role in emotional processing and social understanding. There are a few interesting things happening here. The visual dreaming involves replaying, in various guises, the activity we’ve seen before, which primes us to respond appropriately in the future. It’s a kind of rehearsal for how we’ll respond next time.

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Another interesting theory is that we visualize dreams because it is the only sense which is essentially turned off for nearly ⅓ of our lives, and visualizing our dreams prevents the brain from re-wiring the visual neurons to be used for another purpose due to their lack of active use.

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Those are some of the key processes involved in the brain of healthy sleep, as we understand them today.

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There are also disrupters like alpha-intrusion where wake-like brain activity slips into deep sleep. You're unconscious, but part of your brain is acting like it’s still on duty. This kind of fragmentation reduces how well slow-waves do their job, and it’s one of the reasons people can sleep for hours and still feel like they never really got restorative sleep. Your sleep tracker, and anything measuring time may still view this as deep sleep, but it was functionally weakened.

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We focus on the brain because what happens there drives almost everything else. The brain’s activity during sleep triggers hormonal shifts, immune activity, and nervous system recovery. In poor sleepers, or those who for some reason don’t have proper restorative function, the sympathetic nervous system can remain active, resulting in poor cardiovascular recovery, and other hallmarks of stress, or even the sensation of stress.

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In all of the above processes around sleep, we haven’t really had to touch on time too much. These processes unfold over time, but time isn’t what defines them.

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Rather than asking “how long was I asleep for?” we should be asking “did my sleep meet my restorative needs?”

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Rather than a time-based model of sleep, we’re focused on enhancing the restorative function of sleep. This is functional sleep health.

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If you’re ready to stop measuring sleep by the clock, and start enhancing the restorative function of sleep, join the waitlist and be the first to experience what functional sleep health can really mean.

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