What is Sleep? Science of the Snooze with Dr. Walker

In this post, we’ll unravel the mysteries of sleep stages, the importance of natural light, unconventional sleep tips, and the potential impacts of getting too much (or too little) sleep. 

Whether you’re a troubled sleeper or just looking to enhance your sleep hygiene, there’s something here that could be a game-changer for you. 

What Is Sleep?

Dr. Matthew Walker and host Andrew Huberman peeled back the layers of sleep in a recent podcast episode. They challenged outdated notions and revealed how sleep is far from passive. It’s a complex “ballet,” endlessly fascinating and hugely impactful on our health.

Forget the old idea of a dormant mind and body during sleep. The brain is incredibly active, especially during REM sleep. Some regions are buzzing with up to 30% more activity than when you’re awake.

Non-REM and REM stages alternate, architected in a structured dance across the night. Each stage is critical, playing distinct roles in our health and how we function each day.

Dr. Walker dropped a bombshell, too. What if we got it all wrong? Maybe wakefulness emerged from sleep, not the other way around. It’s a stunning twist—sleep as our default state, and waking life the anomaly.

We’ve moved past the idea of sleep as a chore. It’s a dynamic, evolutionary edge, deeply rooted in all creatures, from us to birds and mammals. 

Sleep is pivotal not just biologically but also in our day-to-day lives.

REM (Rapid Eye Movement) aka ‘Paradoxical Sleep’

This enlightening chat revealed a key point. If you look at someone’s brainwaves, telling REM sleep from wakefulness is tough. But REM sleep gives clues—like the signature rapid horizontal eye movements.

Think of these eye movements as a tell-tale sign. They’re not just rapid, they’re mainly horizontal. This unique pattern helps experts pinpoint when someone is asleep. 

Along with this, muscles play a role too. Just before REM, the brain sends a signal that freezes voluntary muscles. Your body becomes ‘imprisoned’ while your involuntary muscles keep you breathing and your heart pumping.

But why the paralysis? It’s about safety. Our dreams can feel intensely real. Imagine acting them out unconsciously. This paralysis stops us from physically living our dreams, which could be harmful, or worse.

Huberman then went on to something unexpected: physical arousal during REM sleep in both genders. This happens due to ‘autonomic storms’—unstable periods of nervous system activity that spike our heart rate and blood pressure erratically. So even motionless, the body experiences these intense periods.

Intriguingly, paralysis during REM doesn’t affect two muscle groups: the eye-movers and the inner ear muscle. Huberman wonders, could there be a protective reason? Perhaps to maintain functions like the eye’s drainage, which motion supports. But that’s open for further study.

Emotions, Mental Health & Longevity

The speakers spotlights a Harvard study, led by Beth Clearman. It shows REM sleep as a key marker for longevity. They discovered a direct line between REM sleep and lifespan – the less REM, the greater the mortality risk.

The hosts ponder the repercussions of lacking REM sleep, suggesting it could lead to fatal errors in daily life. 

A startling statistic emerges: a 5% drop in REM sleep may increase death risk by 13%. This emphasizes the need for a balanced sleep cycle, not just chasing deep or dream sleep.

The conversation shifts to exercise, another health cornerstone. Experts agree on the necessity of regular physical activity, without shortcuts. 

Zone two cardiovascular workouts, about 150 to 180 minutes weekly, are deemed critical for longevity and disease prevention.

In conclusion, sleep and exercise together form a potent health duo. Before turning to supplements or quick fixes, it’s key to refine one’s sleep habits.

Slow Wave Sleep aka ‘Deep Sleep’

Have you ever wondered if your busy mind could mimic the stillness of deep sleep? Huberman unwrapped this enigma. 

Picture two scenes—light sleep like a gentle stream, deep sleep like an underground river, powerful and serene. This rhythm of the brain, remarkably unified, is a marvel rarely seen in our waking hours.

What’s your sleep pattern? Huberman shares his—aiming for a cozy 10:30 p.m. to 7:00 a.m. snooze. An alarm buzzes at 7:04 a.m., a wry nod to our clock-bound lives. While our sleep styles vary, the pursuit of restful nights unites us.

As we drift off, our heart’s tempo slows. The brain shifts gears—from daytime bustle to the tranquil cadence of deep sleep. 

It’s our body’s own tune-up hour, priming us for a fresh start. And the night’s script follows a pattern, deep sleep leading the early hours, before giving way to a blend of lighter stages and dream-rich REM sleep.

The chat takes a serious turn, touching on the dark side of sleep neglect. Red-eye flights, long doctor shifts—they disrupt our inner rhythms. 

The result? Fatigue, health tolls, and a heart-wrenching link to burnout and tragedy. Huberman and his guest don’t just share concerns—they call for action. Work hour reforms are critical, for caregivers and us all, to keep mistakes at bay and keep us thriving.

Amidst life’s hustle, let’s not forget—the secret to our vitality might just lie in the beautiful rhythm of our sleep.

Compensating For Lost Sleep

Think of sleep as a nightly show with different acts. As the night moves on, REM sleep—the dreamy part—takes center stage. 

Huberman hits us with a question: What happens when we crash late and skip the first act, the deep sleep? Do we leap right into dreams, or does the body demand a rewind?

Sure, our sleep stages can swap places to some extent. Yet, the body craves REM catch-up time, leading to a deep sleep squeeze. The system has a flexible rhythm. It’s tuned to our body’s needs, not the clock.

In research labs, they’ve tinkered with this. They wake folks up early or make them hit the sack late. It’s like playing with a sleep mixtape. The outcome? It matters which part of the sleep you skip. Shortchange yourself on either deep or REM sleep, and the effects are as different as bass and treble.

Huberman dives deeper. Early sleep, with its slow-wave beats, isn’t just a chill tune for muscles and motor skills. It’s got a hand in running our blood pressure and sugar levels too. 

And REM sleep? It’s not just dreaming—it’s linked to hormones that affect our growth and reproduction.

But wait, there’s a twist. The plotline includes alcohol and its role as the party crasher for sleep quality. The drink is no friend to our nightly rest.

Waking in the Middle Of The Night

Sleep comes in stages. Early on, you’re deep in slow-wave slumber. Later, REM takes over. Waking up during the night? It’s typical, often due to noise or temperature changes. 

Huberman’s advice is simple: avoid bright lights and smartphones when you wake up. They make it harder to drift back to sleep.

So, how do these nightly interruptions really impact us? Huberman experiences them too but feels fine during the day. However, could there be long-term effects on our health, learning, or lifespan?

Good news: waking up at night is normal, even more so as we age. Kids might sleep straight through, but adults often wake after each 90-minute cycle. These pauses are so brief; we rarely remember them.

What about sleep efficiency? Being asleep for 85% of the time in bed is healthy. It’s okay to be awake for about 30 minutes in total, spread out in little moments across the night.

Trouble arises if awakenings become lengthy or too frequent, particularly if it takes over 20-25 minutes to fall back asleep. That’s when we should be concerned, as it might signal poor sleep quality and affect our day-to-day performance.

The scientific consensus stresses both sleep quantity and quality. Continuous sleep matters for restfulness, not just the total hours clocked in.

Huberman clarified that normal sleep includes some wakefulness. Occasional disruptions are part of our sleep cycle, so there’s no need for alarm.

Sleep’s significance for our health is ever-growing, and our knowledge continues to deepen. Huberman points out that our comprehension of sleep’s role in optimal functioning is expanding.

To those often waking up at night, take heart. Huberman assures us it’s usually nothing to stress over.

Naps & Non-Sleep-Deep-Rest (NSDR)

Studies sing the praises of napping. Think heart health, balanced stress hormones, sharper memory, and smoother emotions. But here’s the catch: duration is key. Aim for 20 to 90 minutes to avoid sleep inertia—nobody likes waking up groggy.

Walker chimes in with a 1990s discovery. A brisk 26-minute nap upped performance by 34% and alertness by 50%. 

This sparked a ‘NASA nap culture,’ both in space and on the ground. However, napping is tricky. It can mess with adenosine, a sleep-inducing chemical. Daytime napping might make it harder to doze off at night, especially for people with sleeping troubles.

The advice? It’s all about balance. If you sleep well at night, a nap won’t hurt. Insomnia sufferers should think twice. A quick 20-25 minute nap is the sweet spot. It’s enough to refresh without diving too deep. Also, nap early, so you don’t mess with your night’s rest.

Remember, everyone’s different. Huberman nods to his buddy, neurobiologist Lechen Lowe. Afternoon naps are Lowe’s secret to a productive day. 

We shouldn’t judge or label nappers as lazy. Sleep is essential; it’s a basic human right that keeps us healthy and on our toes.

Is It Possible To Get Too Much Sleep?

Hypersomnia is often part of the conversation. It’s when people feel overly sleepy during the day or need excessive sleep. 

Studies link it to depression, but it’s tricky. Depressed people may stay in bed longer, not necessarily sleeping, but avoiding life due to a loss of enjoyment.

The difference between time in bed and time asleep is crucial. Knowing this helps us figure out if someone is really oversleeping or just spending more hours in bed.

Looking at sleep risks, the research is clear: too little or too much sleep can be harmful. There’s a “sweet spot” – typically, seven to nine hours reduces the risk of dying. But beyond nine hours, mortality rates start to rise unexpectedly.

Why does this happen? Science gives us two theories. One is that excessive sleep might be more of a symptom of illness than the cause. The other suggests that people who sleep a lot are actually after better sleep quality because what they get isn’t refreshing enough.

Then there’s a third possibility. Maybe there’s a limit to how much sleep is beneficial. Think about eating, drinking, or breathing – too much or too little can be a problem. Sleep might work the same way.

Andrew Huberman emphasizes that it’s not just about how much we sleep, but the quality of that sleep. It’s essential to focus on “sleep quality” and work on enhancing it.

Viewing Morning SUNLight

The soothing presence of natural sunlight does more than illuminate our days. It syncs our body’s internal clock, promoting restful sleep. 

Andrew Huberman casts a light on this subject. He points to research on melanopsin cells, located in our eyes. These cells don’t form images but they do signal the brain about the day’s circadian time. It’s clear then: soaking up the morning sun is key.

Surprise awaits on overcast days. Even when the sky is gray, outdoor light is magnitudes brighter than indoors. Thousands of lux bright, to be precise. Our indoor lamps? They can’t hold a candle to that. What we see can be deceiving, especially with light.

Here’s a practical take. Dr. Matthew Walker hits the gym not for the equipment, but for sunshine streaming through east-facing windows. He’s not alone. Fitness buffs know the trick — fuse exercise with sunlight to cue wakefulness. It’s a savvy move to lock in a steadfast sleep cycle.

Workplaces, take note. Trading dim cubicles for windowed offices pays off in sleep dividends. 

Studies show leaps in sleep length and efficiency for the window-blessed workers. We’re talking a solid half hour more sleep and a 10% jump in quality. It’s a game changer for those chasing the dream of healthy sleep habits.

Timing matters, though. Walker, flexible with his workout times, coordinates his sweat sessions with his sunlight needs. 

The best time to exercise for sleep purposes may spark debate, but tagging it with sunlight? That’s gold for rhythm regulation.

And here’s a tip from Huberman. Consider ditching sunglasses in the AM. Let those morning rays in, when it’s safe, of course. 

Tim Ferriss is already on board. He jump-ropes eastward at dawn, letting the early light refuel him.

Unconventional Yet Powerful Sleep Tips

Here’s something unexpected: Don’t try to sleep in after a bad night. Dr. Huberman, channeling wisdom from colleague Michael Perlas, says just let it be. 

You might think napping or more caffeine will help, but they can actually mess up your sleep rhythm. Sticking to your normal wake-up time helps build sleepiness for the next night.

Now, consider your wind-down routine. Dr. Huberman likens it to a plane’s gentle landing, not an abrupt switch off. Embrace a calm activity before bed, like stretching or reading – but not in bed. 

And skip the TV with its overstimulating glow. Such rituals signal your body that it’s time to wind down.

Forget counting sheep, advises Dr. Huberman. UC Berkeley’s Professor Alison Harvey found it’s not very helpful. A better approach? Picture a peaceful scene or jot down worries in a “worry journal” earlier in the evening to ease your mind.

Lastly, lose the clock face. Seeing the time tick by can stress you out and make sleep even more elusive.

Give these tips a try. They offer a fresh approach to slumber, blending the “do nothing” strategy with setting the right pre-sleep mood, visual relaxation techniques, and worry journals. 

Other Posts from this Episode

Dr. Matthew Walker Links

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