Episode 128: Why 8 Hours of Sleep Isn't the Goal (And What Actually Is)
Understanding Sleep Architecture, Deep Sleep & REM Sleep
Most people believe that getting 8 hours of sleep is the key to feeling rested. But what if you're hitting that target every night and still waking up exhausted, foggy, or unrefreshed?
In this first episode of a new recovery series, Certified Functional Medicine Practitioner Nicole Goode explains why sleep duration is only one piece of the puzzle. You'll learn how sleep architecture, the structure of your sleep cycles throughout the night, has a far greater impact on your energy, recovery, cognitive function, and overall health than the number of hours you spend in bed.
Nicole breaks down the science of deep sleep, REM sleep, circadian rhythms, and sleep quality in a practical, easy-to-understand way. You'll discover why two people can sleep the same number of hours yet feel completely different the next morning, what causes common 3am wake-ups, how alcohol, caffeine, stress, blood sugar, and hormones affect sleep, and why sleep challenges often worsen during perimenopause and menopause.
This episode answers questions like:
“Why am I still tired after sleeping 8 hours?”
“Why do I wake up exhausted even after a full night’s sleep?”
“What is sleep architecture?”
“What are sleep cycles and how do they work?”
“What causes 3am wake ups every night?”
“Does deep sleep or REM sleep matter more?”
“What causes poor sleep in perimenopause?”
“What things disrupt sleep?”
If you're tired of chasing the "8-hour rule" and wondering why you still don't feel rested, this episode will help you understand what your body is really asking for, and give you practical strategies to improve sleep quality, protect recovery, and wake up feeling more refreshed.
DISCLAIMER: The content in this podcast and related website is not intended to be a substitute for medical advice. It is not intended to be used to diagnose or treat, instead it is designed to help educate and inspire. Always seek the advice of a professional medical practitioner or qualified health practitioner. Never ignore or disregard advice given to you based on information in this podcast or related website and do not delay in seeking medical advice.
Timestamps:
[01:17] - Why 8 Hours of Sleep Isn't the Goal
Why sleep duration alone doesn't determine whether you wake up feeling rested.
[02:32] - Sleep Architecture Explained
Understanding sleep cycles, deep sleep, REM sleep, and what actually drives recovery.
[04:10]- Deep Sleep vs REM Sleep
How your brain and body repair themselves during different stages of sleep.
[07:53]- 5 Ways to Improve Sleep Quality Naturally
Practical strategies to protect your sleep architecture and improve recovery.
[10:40]- Why You Keep Waking Up at 3AM
The hidden roles of blood sugar, cortisol, stress, and alcohol in nighttime wake-ups.
[15:00]- Hormones, Perimenopause & Poor Sleep
Why sleep often changes throughout the menstrual cycle and during menopause.
[19:00]- The Real Goal of Better Sleep
How to stop chasing hours and start building truly restorative sleep.
“Two people can both sleep eight hours and have completely different nights and completely different mornings. It is not how long you are unconscious that determines how you feel. It’s the structure of what your body does in that time. We’ve been treating sleep duration like the whole scorecard when it’s actually just one line on the scorecard. That’s why you can hit your number and still feel terrible. Because the number was never measuring the thing that actually makes you feel rested.”
Essential learnings from this episode…
Sleep quality matters more than sleep duration. Getting 8 hours of sleep doesn't guarantee you'll feel rested.
Your energy levels depend largely on your sleep architecture, including how much deep sleep and REM sleep you're getting throughout the night.
Deep sleep and REM sleep have different jobs. Deep sleep supports physical recovery, growth hormone release, and brain detoxification, while REM sleep helps with emotional processing, learning, and memory consolidation.
Sleep timing directly affects recovery. The same 8 hours of sleep can produce very different results depending on when you sleep. Consistent bedtimes and wake times help align your sleep with your body's natural circadian rhythm.
Recurring nighttime waking can be linked to blood sugar imbalances, stress, cortisol dysregulation, alcohol consumption, or hormonal changes rather than simply "being a bad sleeper."
Even when they don't stop you from sleeping, alcohol and caffeine can reduce sleep quality by interfering with deep sleep and REM sleep, leaving you less refreshed the next morning.
Hormones play a major role in sleep quality. Changes in progesterone and oestrogen throughout the menstrual cycle, perimenopause, and menopause can significantly affect sleep quality, nighttime waking, and overall recovery.
EPISODE 128
Important links & mentions from this episode
The Optimal You 7 Day Reset (£7.99)
Episode 103: Why You Still Feel Exhausted (Even After 8 Hours of Sleep)
Episode 107: Why Feeling Tired All the Time Isn’t Normal (What Your Body Is Telling You)
Goode Health Clinic Functional Medicine Packages
Take the FREE MitoImmune Health Assessment
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(0:00 - 0:08)
I want to start this episode with something a little bit uncomfortable. You might be doing everything right with your sleep. You might be getting to bed at a sensible time.
(0:09 - 0:22)
You might be genuinely hitting your eight hours, and you still might be waking up exhausted, foggy, heavy, and like you've barely slept at all. And if that's you, I don't think your problem is effort. I think your problem is the target.
(0:22 - 0:41)
Because the eight-hour rule, the number that we've all been chasing, is on its own the wrong thing to be aiming for. I'm Nicole Goode, Certified Functional Medicine Practitioner, and this is the Goode Health Podcast. And this is the first episode of a short series that I'm doing on recovery, because recovery is part of health that high-performing people are frankly the worst at.
(0:41 - 0:55)
And we are starting with sleep, but not with sleep hygiene. You've heard the sleep hygiene tips a hundred times. We're starting somewhere that is actually more useful, and that is your sleep architecture, with what actually happens inside those hours.
(0:56 - 1:05)
Here's the through line for today. It is not how long you are unconscious that determines how you feel. It's the structure of what your body does in that time.
(1:05 - 1:21)
Two people can both sleep eight hours and have completely different nights, and completely different mornings. So by the end of this episode, we're going to stop chasing the number and start protecting the structure. Let's start with the eight-hour rule itself, because I don't want to just dismiss it.
(1:21 - 1:26)
I want you to understand why it's stuck around. Eight hours stuck because it's simple. It's one number.
(1:26 - 1:35)
It's memorable. It's easy to repeat. And especially now with every watch, ring, and app that is tracking us, it's easy to measure.
(1:35 - 1:47)
And on average across a population, the recommendation isn't all that wrong. Most adults do need somewhere in that seven to nine-hour range of sleep. But here's the problem with using it as your only target.
(1:47 - 1:56)
Duration is quite a crude metric. Think about what I slept eight hours actually tells you. It tells you how long you were in bed, more or less asleep.
(1:57 - 2:08)
But it tells you nothing about the quality of that sleep. It tells you nothing about the timing of it, whether those were the right eight hours. And it tells you nothing about regularity, whether tonight looked anything like last night.
(2:08 - 2:13)
So duration is one input. And it's a real input. I'm not throwing it away.
(2:14 - 2:21)
But it is one line on the scorecard. And we've been treating it like the whole scorecard. And that's why you can hit your number and still feel terrible.
(2:21 - 2:32)
Because the number was never measuring the thing that is actually going to make you feel rested. Let's talk about what actually happens when you sleep. What is going to make you feel rested? Let's go inside the night.
(2:32 - 2:41)
When you sleep, you're not just switched off. You're moving through an architecture, a structure. During that time, you cycle through different stages of sleep.
(2:41 - 2:49)
And each stage is doing a different job. So broadly speaking, there are three things I want you to know about. There is light sleep, which is the bulk of your night.
(2:49 - 2:57)
And it's the connective tissue between everything else. Don't dismiss it, but it's not the headline. Then there's deep sleep, sometimes called slow-wave sleep.
(2:58 - 3:14)
And that is your deep physical restoration. And then there's REM sleep or REM sleep, the stage most associated with that vivid dreaming, which is doing a lot of the work for your brain and your emotions. And you move through these three stages in a cycle that lasts roughly 90 minutes.
(3:14 - 3:25)
So across a full night, you're not having one sleep. You're running that 90-minute cycle around four to six times. But here is the single most important fact in this whole episode.
(3:25 - 3:35)
The stages are not spread evenly across the night. So your deep sleep is front-loaded. You get most of it in the first half of the night, in those early cycles.
(3:35 - 3:43)
And your REM sleep is back-loaded. So the REM portion of each cycle gets longer and longer towards the morning. Sit with what that means.
(3:43 - 4:01)
It means that when you sleep changes what kind of sleep you get. If you regularly push your bedtime late, but you still have to be up at the same time, you're not just losing an hour of sleep. You might be specifically shaving off your deep sleep at one end or your REM sleep at the other.
(4:01 - 4:10)
You're not just losing a random hour. You could be losing a particular job that was supposed to get done in that hour. So let's have a look at what these jobs are.
(4:10 - 4:23)
What does the body actually do whilst you're asleep? Let's take deep sleep first. Deep sleep is when a huge amount of your physical repair happens. It's when your body releases growth hormone, which is central to repair and recovery.
(4:23 - 4:31)
And deep sleep is when something genuinely remarkable happens in your brain. And that's the glymphatic system. And I love this one.
(4:31 - 4:46)
So let's explain it simply. Think of the glymphatic system as your brain's overnight cleaning crew. During the day, your brain is busy and it generates a lot of metabolic waste, which are the natural byproducts of all the activity that happens whilst you're awake.
(4:46 - 5:01)
And during deep sleep, your brain runs a clearance process that flushes that waste out. It's basically the cleaners coming in after the office is emptied for the night. You cannot fully run that process while you're awake and the building is still full.
(5:01 - 5:05)
You need the deep sleep. That's the window for it. And then we have the REM sleep.
(5:06 - 5:12)
So that's the back half of the night. And this is doing work for your mind. So REM is heavily involved in emotional processing.
(5:12 - 5:23)
It's part of how you take the emotional charge out of the day's experiences. And it's also involved in memory consolidation. So it's filing what you've learned into something that lasts.
(5:23 - 5:35)
So moving things from that short-term memory to long-term memory. If you've ever noticed that everything feels more emotionally warm or brittle after a bad night, that's not you being dramatic. That's because you've missed some of that REM sleep.
(5:35 - 5:52)
And underneath all of this, your body is running a precise hormonal schedule. Melatonin rises in the evening as it gets dark, helping you to wind down. And cortisol, your alerting hormone, is meant to be at its lowest at night and then rise in the early morning to help you wake up and feel switched on.
(5:52 - 6:02)
So your body isn't passive at night. It's running a very, very tightly timed shift. Repair crew, then cleaning crew, and then the filing department, all on schedule.
(6:02 - 6:12)
While you're lying there completely unaware of any of this going on. Which brings us to the thing that really matters. And the reason that just getting eight hours falls down.
(6:12 - 6:20)
If your body is running a timed schedule, then timing isn't a detail. Timing is the whole game. Here's the clearest way I can put it.
(6:20 - 6:32)
Eight hours of sleep starting at 2am is not the same as eight hours starting at 10.30pm. Even if it's the same duration. It's a completely different night. Because the 2am version is fighting your body's clock.
(6:33 - 6:45)
It's misaligned with your natural cortisol and melatonin rhythm. And it's shifting your deep sleep and your REM sleep into the wrong relationship with your morning. So the hours are the same, but the architecture is not.
(6:46 - 6:54)
And then there's regularity. And this is something the research has really sharpened in recent years. It increasingly looks like the consistency of your sleep.
(6:54 - 7:05)
So going to bed and waking up at similar times is its own powerful signal to your health. Working alongside duration. And by some measures, mattering even more than duration.
(7:05 - 7:15)
Your body is a creature of rhythm. It runs better on a predictable schedule than on an erratic one. Even if the erratic one technically averages out to enough hours.
(7:15 - 7:27)
So that's why you can do the right number of hours and still feel awful. Because the things that wreck your architecture often leave the duration looking completely fine. Alcohol is a big one here and we'll come back to it.
(7:27 - 7:33)
But caffeine too late in the day. A big heavy meal close to bedtime. Light in the evening or light in the bedroom.
(7:34 - 7:41)
A room that's too warm. Every one of those can damage the structure of your night. While your tracker still cheerfully reports that you've had eight hours sleep.
(7:41 - 7:53)
The number lies because the number was never measuring the structure. So let's make this practical. How do you actually protect your sleep architecture? I'll give you a handful that do the most.
(7:53 - 8:05)
One, protect the front half of your night. So remember that's your deep sleep window, your physical repair, your brain's cleaning crew. Getting to bed at a reasonable consistent hour isn't about being virtuous.
(8:05 - 8:16)
It's about not sacrificing the most restorative part of your night. The late hours you stay up are disproportionately expensive. Two, anchor everything to a consistent wake time.
(8:16 - 8:25)
Pick a wake time you can actually keep and keep it. Including at the weekends or at least close enough to it. Your wake time is the anchor that the rest of your rhythm hangs off.
(8:25 - 8:37)
A consistent wake time does more for your sleep than almost anything you do at night. Three, get daylight into your eyes early. Within 30 to 60 minutes of waking, get outside or at least to a bright window.
(8:37 - 8:47)
That morning light is the signal that sets your body clock for the day. And a clock that's clearly set in the morning keeps better time at night. Morning light is genuinely a sleep tool.
(8:47 - 8:55)
We just use it at the wrong end of the day to think about it. Four, the timing rules for the two big disruptors. Caffeine.
(8:55 - 9:08)
Give yourself a cutoff somewhere between 12 p.m. and early afternoon. One half one, two o'clock as an absolute maximum. Because caffeine lingers in your system far longer than people assume.
(9:08 - 9:21)
And everybody's slightly different with caffeine. Some people need to finish drinking caffeine at 12 p.m. Some can manage to push it till one a little bit later. But caffeine is going to stay in your system a lot longer than you think.
(9:21 - 9:29)
So that caffeine that you have after lunchtime is going to affect your sleep. And then alcohol. Alcohol might help you to fall asleep.
(9:29 - 9:37)
It might even help to keep you asleep. People swear that it doesn't affect them. But alcohol specifically disrupts your sleep architecture.
(9:38 - 9:47)
It interferes with your REM in particular. So you get the hours, but you don't get the structure. That is why you can sleep through the night after drinking.
(9:47 - 9:56)
And still wake up feeling unrefreshed or a bit flat. Try leaving around three hours between your last drink and your bedtime. And pay attention to how differently you wake up.
(9:56 - 10:07)
Five, let the room get cool and dark. And keep the last hour before bed low light. Your body needs to feel a temperature drop to move into sleep properly.
(10:07 - 10:15)
And it needs darkness to allow melatonin to do its job. You're not being precious. You're giving the architecture the conditions that it needs.
(10:15 - 10:21)
Now everything that I've just given you is foundational. And it genuinely works. But I don't want to leave it there.
(10:21 - 10:32)
Because there are two situations where the general advice isn't quite enough on its own. Two of the most common reasons people really struggle. And they deserve more than one line tips.
(10:32 - 10:41)
So let's take a little time over these and go through them properly. Let's start with the one I get asked about most. Probably more than anything else when it comes to sleep.
(10:41 - 10:50)
You fall asleep absolutely fine. And then like clockwork, you're wide awake at three or four in the morning. Often with a busy mind or a slightly racing feeling.
(10:51 - 11:02)
And you lie there watching the hours you've got left tick down. Does that sound familiar? So the first thing I want to say is genuinely reassuring. Waking briefly in the night is not in itself a problem.
(11:02 - 11:18)
Remember those 90-minute cycles we talked about? You naturally surface a little between them. Everybody does. So the real question is not, why do I wake up? The question is, why am I becoming fully awake and then can't get back to sleep? And that, that has causes.
(11:18 - 11:24)
And once you know them, you can do something about them. So let's look at what the main ones are. The first is blood sugar.
(11:24 - 11:37)
While you sleep, your body is quietly keeping your blood sugar stable in the background. But for some people, it dips too low in the small hours. And when it does, the body's response is to release cortisol and adrenaline to push that sugar back up.
(11:37 - 11:49)
And cortisol and adrenaline are your alerting hormones. Quite literally, your wake-up chemistry. You wake often around that 3 or 4 a.m. mark feeling wired or anxious for no reason that you can actually name.
(11:49 - 12:06)
And the fix for that is usually in your evening meal. Going to bed genuinely hungry or eating a dinner that's very light or very heavy on a refined carbohydrate that is spiking and then crashing. All of that, all of those things can set up that middle-of-the-night dip.
(12:06 - 12:20)
So a balanced dinner, one with protein, with fats, with fibre, helps to hold you steady through the night. The second is cortisol itself and stress. Now, your cortisol is meant to start gently rising in the second half of the night.
(12:20 - 12:30)
And that's normal. That's the system getting ready to wake you up. But if you're under chronic stress, if your stress system is dysregulated, that rise can come too early and too sharply.
(12:30 - 12:53)
And it will wake you, usually with a mind that switches straight on, to that to-do list or the worry or the replaying, that wide awake and racing at 3 a.m. feeling. If that's you, the real work is in your days, in your daytime stress load, far more than in your nights. And third, one we have to come back to because we mentioned it already, but we really only talked about half of the story, and that's alcohol.
(12:53 - 12:59)
I said that alcohol disrupts your REM sleep. But here's the other half of the story. Alcohol helps you fall asleep.
(12:59 - 13:10)
That's exactly why people think it's helping them. But a few hours later, as your body finishes metabolising it, you get a rebound. So a little surge of alerting energy and a knock to your blood sugar.
(13:10 - 13:22)
And that rebound lands you right in the early hours. That very often is around that 3 a.m. time where you're awake after an evening of drinks. It's not the falling asleep that the alcohol ruins, it's the staying asleep.
(13:22 - 13:36)
And then the fourth driver is hormonal. And because this one is so significant and so specific to women, I'm going to give it its own section in just a moment. But before I do, what do you actually do in the moment at 3 a.m. when you wake up? So a few things.
(13:36 - 13:44)
First, and I know this is really hard, but don't watch the clock. Turn it away from you. Because the moment you start doing the maths, if I fall asleep now, I'll get four hours.
(13:44 - 14:02)
If I fall asleep now, I'll get three hours. You have activated the very stress response that is keeping you awake in the first place. The clock is not your friend at 3 a.m. Second, and this is one that surprises people, if you've been properly awake for a while and you're getting frustrated, don't just lie there fighting it.
(14:02 - 14:15)
Get up. Keep the lights low and do something calm and a bit boring and go back to bed when you actually feel sleepy. Because lying in bed awake and frustrated night after night quietly teaches your brain to associate your bed with being awake.
(14:16 - 14:22)
And that is a pattern that you do not want to build. Third, keep it dark. So no bright lights and ideally no phones.
(14:22 - 14:31)
Light tells your body it's morning, and that is the opposite of the message you want to send. And then just take the pressure off. Don't lie there trying to sleep.
(14:31 - 14:38)
Trying is effort, and effort is arousal. Aim instead for calm, restful lying down. Just slow your breathing right down.
(14:38 - 14:48)
Make your exhale longer than your inhale, and let that just be enough. Rest is still valuable even when sleep is being slow to come back. Because here's the reframe I want you to hold on to.
(14:48 - 14:59)
A 3 a.m. waking up is not a personal failing. It's information. It's your body telling you something about your blood sugar, your stress, your evening, your hormones, and information you can work with.
(14:59 - 15:12)
That brings me back to that fourth driver, the hormones. And honestly, to one of the biggest blind spots in the whole way we talk about sleep. Almost all of the standard sleep advice treats a sleeper as a fixed, unchanging thing.
(15:12 - 15:17)
But if you're a woman, your sleep is not fixed. It moves. It moves across the month.
(15:17 - 15:26)
It moves across the decades. Because it moves with your hormones. So if your sleep seems to change for no reason you can point to, I want you to know that there is often a reason.
(15:26 - 15:31)
And it's often hormonal. You just haven't found that reason yet. Let's start with the monthly cycle.
(15:32 - 15:36)
Two hormones matter most here. Progesterone is calming. It's genuinely sleep supportive.
(15:37 - 15:49)
And oestrogen supports the quality of your sleep too. Now in the second half of your cycle, the week or so before your period, those hormones shift and then fall away. And as they fall, a lot of women's sleep worsens.
(15:49 - 15:55)
So we get lighter sleep, more waking. That restless premenstrual few nights. There's even a temperature piece to this.
(15:56 - 16:09)
Your core body temperature runs slightly higher in that part of the cycle. And remember what we said earlier in this episode, your body needs to feel the temperature drop to sleep well. So in that premenstrual window, your own biology is in a small way working against you.
(16:10 - 16:18)
None of that is you being a bad sleeper. That is a predictable monthly pattern and one you can plan for. So expect that week to be a slightly harder sleep week.
(16:18 - 16:31)
Be more protective of your fundamentals throughout it, not less. And then there's the big one, perimenopause or menopause. Disrupted sleep is one of the most common and one of the most exhausting symptoms of that whole period.
(16:31 - 16:42)
And there are a few things coming together at once. I remember when we're talking about perimenopause and menopause, we could be talking about more than a decade in a woman's life. You're losing progesterone, that calming sleep supportive hormone.
(16:43 - 16:56)
So sleep naturally is becoming lighter and more easily broken. And that's a big part of why the 3am waking that we've just talked about can arrive or get dramatically worse from your mid-40s onwards. And then there's the hot flushes and the night sweats.
(16:57 - 17:07)
So those temperature surges don't only happen in the daytime. At night, they can pull you straight out of a deep sleep, sometimes so briefly that you don't even register the flush. You just know you're awake again.
(17:07 - 17:16)
And oestrogen is woven into your temperature regulation and your mood chemistry too. So as it fluctuates, all of that becomes less stable. And here's where it can become a difficult loop.
(17:17 - 17:26)
Poor sleep makes the next day's mood harder and stress harder to manage. And that pushes your cortisol up. And higher cortisol makes the next night's sleep worse again.
(17:26 - 17:37)
And round and round it goes. So if you're in that stage of life and you feel like your sleep has simply fallen apart, you've not become a broken sleeper. You're just moving through a real physiological shift.
(17:37 - 17:48)
And what you're experiencing makes complete sense. So what helps? First of all, I think naming it helps. So much of the distress here comes from women quietly believing that something has gone wrong with them.
(17:48 - 17:58)
When what's actually happening is a known and understood transition. That reframe alone takes some of the load off. Beyond that, the fundamentals from earlier in this episode don't become less important.
(17:58 - 18:02)
They become more important. Temperature especially. Really keep that bedroom cool.
(18:03 - 18:14)
Get into breathable, natural fibre bedding. Dress in layers so you can throw them off in the night. Your consistent wake time, your low light last hour, your morning light, all of it matters more now.
(18:14 - 18:19)
Because your system has less of its own buffer. And it needs more support from you. And alcohol.
(18:20 - 18:25)
I'll be honest with you. Alcohol tends to make those flushes worse. And also the night time waking worse.
(18:26 - 18:34)
So this is a stage in life where its cost genuinely does go up. And the last thing. This is a stage where I really don't want you to just push through it on your own.
(18:34 - 18:46)
Sleep this disrupted, driven by this much hormonal change, is worth proper individualised support. It's not a weakness to go and ask for help. It's the sensible thing to do because your sleep does not exist in isolation.
(18:46 - 18:59)
It is woven through your hormones, your stress system, your thyroid, your energy, all of it woven together. Now here's why this is the start of a small recovery series and not just a standalone sleep episode. Sleep doesn't sit on its own.
(19:00 - 19:16)
Your sleep architecture sits underneath your energy, your mitochondrial function, your immune resilience. It's foundational to all of it. So if you've listened to this and recognised that poor sleep structure might be quietly driving your fatigue, the mitoimmune health assessment is built to look at exactly those connected systems together.
(19:16 - 19:30)
And we've linked it in the show notes below. And if you want sleep set properly in its place as one of the lifestyle S's and how to work with the other pillars, that's all laid out in my book, Optimal You. Here's what I want you to take from this episode.
(19:30 - 19:40)
Stop chasing the number. Eight hours on its own was never the goal. It can't see the structure of your night and the structure, that architecture is what makes you feel rested.
(19:40 - 19:53)
Protect the front half of your night and anchor it with a consistent wake time. Get your morning light, mind your alcohol and give your body the timing and regularity it's quietly built around. I hope you've enjoyed today's episode.
(19:53 - 19:58)
We'll be back next week with another recovery episode. I'll see you then on The Goode Health Podcast.
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