And It Has Nothing to Do With Bad Sleep

Read time: 5 minutes

First of all, I want to start this week's newsletter by saying thank you to everyone who got in touch wishing me a happy birthday, it really means a lot.

I would say it feels odd when a 'stranger' messages me to wish me a happy birthday, but I've been creating content for so long that it's second nature to me, and I'm extremely grateful for it.

I took my butt down to the beach on Saturday, went for a dip, had a few bottles of local beer (5), read a few chapters of a book (Split The Difference by Chris Voss), and did my best to actually switch off.

I won't lie, it's why I had the beers. I knew if I had a few, I wouldn't be able to do any meaningful work afterwards, and I was indeed correct 😂 Yeah, it may not be the 'best' solution, but I didn't touch my laptop when I got home ha!

I'm also at that stage in my life where my body really f*cking hates alcohol. Of course, it's great at the time, but at 35, even just a few drinks have me groggy the next morning, not ideal when had a run planned.

Well, I got the run smashed, in 28-degree heat, might I add, and then cooled off by dipping my feet in the sea.

Now, my run, and as a result, my entire day, was close to being scuppered by those few drinks. Not just because I felt a bit sluggish the next morning, but rather because my sleep was sh*t.

I uncharacteristically woke up a few times during the night, resulting in a broken, restless sleep. Something that might feel all too relatable.

Well, that's exactly where we're going with today's email, and I promise you it's a good one! After a long-winded opening, let's get stuck into it...

Answer me this ↓

Sound familiar at all?

3:17 AM. Wide awake.

Heart beating a touch too fast.

Mind already running through tomorrow.

You weren't dreaming.

You're not particularly thirsty.

The room is quiet.

The bed is comfortable.

You just… woke up.

And now you can't fall back asleep!

If this is happening to you once or twice a year, it's probably nothing.

If it's happening 3+ nights a week, you're not alone, and it is anything but random.

A large epidemiological study led by Dr Maurice Ohayon at the Stanford Sleep Epidemiology Research Centre, published in Sleep Medicine in 2010, surveyed nearly 9,000 adults across three US states (1).

They found that 35% of those surveyed reported waking at least 3x nights per week.

That's a pretty staggering number when you consider how vital a role sleep plays in our health, wellbeing, and performance.

The issue with these unwanted wake-ups is that the majority of people are treating them as a sleep problem, when more often than not, it isn't sleep-related, but rather...

It's a hormone problem, masquerading as a sleep problem.

And what sleep-wrecking hormone is it exactly?

It's one you've certainly heard of, it is of course...

→ Cortisol.

It's released by the adrenal glands and controlled by a feedback loop between the brain and the body called the HPA axis (hypothalamic-pituitary-adrenal axis). If you remember that mouthful, I'll be impressed 😂

Cortisol gets a bad reputation, but it's not the villain.

You most likely know it as one thing: a stress hormone. And we know that too much stress is a bad thing, so logically you would think that keeping cortisol at bay would be a good thing, right?

Well, it's not that simple. You see, cortisol is a regulator.

Yes, it is your body's primary stress hormone, but it plays a key role in a healthy, highly functional body.

In a healthy body, cortisol follows a clean 24-hour rhythm.

When we relate this to sleep, there is a cycle often referred to as the 'Sleep-wake cycle' and as Johns Hopkins University expertly puts it:
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"The sleep-wake cycle is a 24-hour biological rhythm regulated by the body's internal clock (circadian rhythm) and the brain's drive to sleep (sleep homeostasis). It dictates when you feel alert or drowsy by balancing hormone release, like melatonin for sleep and cortisol for waking. It dictates when you feel alert or drowsy by balancing hormone release, like melatonin for sleep and cortisol for waking (2)."

That last bit is VERY important, so read it again.

"Melatonin for sleep and cortisol for waking."

Melatonin is the sleepy hormone.

Cortisol is the wakey wakey hormone.

When your body ships these two hormones around it determines what kind of sleep you're going to get.

In the case of cortisol, it generally bottoms out around midnight, allowing deep sleep to begin. It then starts a gradual rise in the early hours, preparing your body to wake. Then it peaks sharply in the first 30 to 45 minutes after you open your eyes, what researchers call the 'cortisol awakening response', characterised in detail by Dr Angela Clow and colleagues in a 2010 review published in Neuroscience & Biobehavioral Reviews (3).

From there, it declines steadily, returning to its lowest point by late evening.

That's the design. Elegant, predictable, and exactly what you want.

That's the best-case scenario, but we know life in general tends to be anything but a best-case scenario, and when that rhythm breaks and the problems start to set in, that's when middle-of-the-night wake-ups enter the equation.

What the science actually shows

In 2001, a research team led by Dr Alexandros Vgontzas at Penn State College of Medicine, working with the renowned endocrinologist George Chrousos at the National Institutes of Health, published a landmark study in The Journal of Clinical Endocrinology & Metabolism (4).

They took 11 young chronic insomniacs and 13 matched healthy sleepers, monitored them for four consecutive nights in a sleep lab, and measured their cortisol for 24 hours straight.

The insomniacs had higher cortisol levels around the clock.

But the most striking finding was when the spikes happened:

The largest elevations were in the evening and the first half of the night, exactly when cortisol should be at its lowest. And the worse their sleep was, the higher the cortisol levels were.

That single study reframed how we think about insomnia. It wasn't just "bad sleep." It was a measurable, hormonal state of hyperarousal that persisted around the clock.

Twenty years later, a team at the University of Freiburg led by Raphael Dressle put that finding through the strictest test there is. Their 2022 systematic review and meta-analysis, published in Sleep Medicine Reviews, pooled 20 case-control studies covering 449 chronic insomniacs and 357 good sleepers (5).

The conclusion was straightforward:

People with chronic insomnia have higher cortisol than people who sleep well, and the gap is biggest in the evening, right when cortisol should be winding down.

Hundreds of people. Twenty separate studies. Same result every time.

This isn't guesswork. It's something you can literally measure in someone's blood.

Why 3 AM, specifically?

Two reasons.

First, cortisol naturally begins rising in the early hours of the morning. In a healthy person, this rise stays below the threshold needed to wake you. In someone with elevated baseline cortisol, the rise crosses that threshold, and you're awake.

Think of it like a cup. Cortisol slowly fills it overnight. If you went to bed with the cup mostly empty, you've got plenty of headroom.

But if you went to bed with the cup already three-quarters full, from chronic stress, poor recovery, alcohol, blood sugar issues, or unprocessed worry, that natural rise overflows.

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There's a second reason 3 AM hits so hard.

Sleep is lighter in the second half of the night. Deep, slow-wave sleep is concentrated in the first few hours, while the early morning hours are more REM-dominant, a lighter, more easily disturbed state.

So even a modest cortisol nudge in the second half of the night has a much bigger effect than the same nudge would in the first half.

Put those two things together, a rising hormone and a lighter sleep state, and you have your answer.

3 AM isn't random; it's exactly when your system is at its most vulnerable.

What's filling your cup

So the real question becomes:

What's keeping your cortisol cup so full in the first place?

The answer is almost always a combination of the same handful of factors. Most of them are modifiable. The big ones include:

Chronic stress. This is the obvious one, but it's not just emotional stress. Work pressure, unresolved worry, perfectionism, and constant low-grade tension all keep your cortisol cup fuller than it should be.

Over time, the brain's feedback receptors that should "switch off" cortisol become desensitised, and baseline levels stay elevated, particularly in the evening. This is a recipe for sleep disaster!

Blood sugar instability. This one surprises most people. When blood glucose drops too low overnight, the brain perceives it as a survival emergency.

As Dr Philip Cryer explained in a foundational 2007 paper in the Journal of Clinical Investigation, the brain triggers a release of counter-regulatory hormones, including glucagon, adrenaline, and cortisol, to drag glucose back up (6).

You wake up at 3 AM with a racing heart and a spinning mind, thinking it's anxiety. It's often just your liver getting an emergency call from your brain to kick into action.

Late-night simple carbs (yes, those delicious ones that hit harder at 11 pm, those), going to bed under-fuelled, and poor metabolic health all increase the risk of this rather annoying issue from happening.

Alcohol. This deserves its own paragraph because the evidence is so consistent.

In 2025, a research team led by Carissa Gardiner at Monash University in Australia published a systematic review and meta-analysis of 27 studies in Sleep Medicine Reviews, examining alcohol's effect on sleep in healthy adults (7).

The findings were sobering:

Alcohol consistently delays the onset of REM sleep and reduces total REM duration, and the disruption follows a clear dose-response curve.

In Leyman's terms, even two standard drinks were enough to disrupt REM sleep.

More drinks? You guessed it: more disruption.

The mechanism is brutal. Alcohol initially sedates you, then causes a rebound activation as your body metabolises it. A drink at 10 PM is fully cleared around 2–3 AM, the exact window of the wake-up.

Add in suppressed melatonin, dehydration, and blood sugar fluctuations, and you have a near-perfect recipe for waking up wired in the early hours.

Whoopty f*cking do!

That nightcap isn't helping you sleep. It's setting an alarm instead.

Age and hormonal shifts. Cortisol regulation gets less forgiving with age. In a 2001 study published in The Journal of Clinical Endocrinology & Metabolism, a group of researchers at Penn State gave a dose of corticotropin-releasing hormone, the brain signal that triggers cortisol, to twelve middle-aged men and twelve young men, then monitored their sleep.

Both groups produced similar amounts of cortisol in response, but the middle-aged men had significantly more wakefulness and significantly greater loss of deep sleep. The young men's sleep was barely affected.

Plainly put, the same hormonal signal hits a middle-aged brain much harder.

In women, perimenopause and menopause add another layer entirely, as oestrogen and progesterone, both buffers against cortisol, decline.

What actually helps

That's the bad news.

The good news is that the same biology cuts both ways.

The same sh*t that's keeping you awake at 3 AM responds pretty well, and often quickly, to the right daily inputs.

The cup you went to bed with isn't fixed. It's the result of what you did in the eighteen hours before your head hit the pillow.

A 2012 randomised, double-blind, placebo-controlled trial published in the Journal of Research in Medical Sciences, led by Behnood Abbasi at Shahid Beheshti University in Iran, gave 46 elderly insomnia patients either 500 mg of magnesium daily or a placebo for eight weeks (9).

The magnesium group showed measurable improvements in sleep efficiency, total sleep time, and early morning awakening, and crucially, reductions in cortisol alongside increases in melatonin.

That's literally all you could want!

Beyond magnesium, the evidence base is consistent on what works and will come as no shock to you:
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• Cutting alcohol, especially in the three hours before bed.
• Stabilise blood sugar overnight with a small protein-rich snack 30–60 minutes before sleep.
• Getting morning sunlight within 30 minutes of waking, to reinforce the cortisol awakening response at the right time, a mechanism supported across the circadian rhythm literature.
• Building muscle through resistance training, which improves glycogen storage and overnight glucose stability.
• Anchoring your wake time daily, more important than your bedtime for circadian regulation.
• Cutting caffeine after noon, given its 5–6-hour half-life. Although my last coffee is usually at 3-4 pm, but I'm also addicted 🫠 But I still sleep like a baby.
• And last but not least, drum roll please.... 🥁🥁🥁🥁🥁🥁🥁

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Addressing the bloody cause of your elevated stress levels! What in your life is causing you chronic stress? Is it the unrelenting workload, the worry you've never quite put down, or open loops you're not closing?

You NEED to find a solution for managing it effectively.

Not eliminating it, but rather getting it under control.

Before I leave you, I want you to remember that waking at 3 AM isn't a personal failing.

But it is your body responding to what you did yesterday.

The fix is NOT a pill.

It ain't some expensive new gadget.

And it isn't a darker room.

It's the boring stuff that everyone knows will help them sleep better, but still brushes over their effectiveness.

Less alcohol, steadier blood sugar, better stress management, morning sunlight, time on your feet, an earlier dinner.

Things you already know.

The good news?

Cortisol responds quickly, and most people see a difference within a couple of weeks.

You're not stuck with this. You never were. And if you're willing to put the work in, you never will be again!

Here's to sleeping better and stressing less 😴

Have a great week.

Your pal,

Mark ✌️

Quote for the day

Mark Gray

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P.S. Whenever you’re ready, here are a few ways I can help you:
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1. ​My NEW sleep ebook is live — and yours free. If you’re tired of feeling tired, this guide breaks down how to fix your sleep and boost energy, focus, and recovery. Grab your copy by clicking here now.​
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2. ​The Paradigm Project: Want to get strong, lean, and energised — without burning out? If you’re an ambitious entrepreneur or professional who wants results without wasting time, find out more about my 1-1 coaching here.​
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References

1. Ohayon, M.M., Krystal, A., Roehrs, T.A., Roth, T., & Vitiello, M.V. (2010). "Using difficulty resuming sleep to define nocturnal awakenings." Sleep Medicine, 11(3), 236–241.
2. ​https://www.hopkinsmedicine.org/health/conditions-and-diseases/sleepwake-cycles​
3. Clow, A., Hucklebridge, F., Stalder, T., Evans, P., & Thorn, L. (2010). "The cortisol awakening response: more than a measure of HPA axis function." Neuroscience & Biobehavioral Reviews, 35(1), 97–103.
4. Vgontzas, A.N., Bixler, E.O., Lin, H.M., Prolo, P., Mastorakos, G., Vela-Bueno, A., Kales, A., & Chrousos, G.P. (2001). "Chronic Insomnia Is Associated with Nyctohemeral Activation of the Hypothalamic-Pituitary-Adrenal Axis: Clinical Implications." The Journal of Clinical Endocrinology & Metabolism, 86(8), 3787–3794.
5. Dressle, R.J., Feige, B., Spiegelhalder, K., Schmucker, C., Benz, F., Mey, N.C., & Riemann, D. (2022). "HPA axis activity in patients with chronic insomnia: A systematic review and meta-analysis of case-control studies." Sleep Medicine Reviews, 62, 101588.
6. Cryer, P.E. (2007). "Hypoglycemia, functional brain failure, and brain death." Journal of Clinical Investigation, 117(4), 868–870.
7. Gardiner, C., Weakley, J., Burke, L.M., Roach, G.D., Sargent, C., Maniar, N., Miller, D.J., & Halson, S.L. (2025). "The effect of alcohol on subsequent sleep in healthy adults: A systematic review and meta-analysis." Sleep Medicine Reviews, 80, 102030.
8. Vgontzas, A.N., Bixler, E.O., Wittman, A.M., Zachman, K., Lin, H.M., Vela-Bueno, A., Kales, A., & Chrousos, G.P. (2001). "Middle-Aged Men Show Higher Sensitivity of Sleep to the Arousing Effects of Corticotropin-Releasing Hormone Than Young Men: Clinical Implications." The Journal of Clinical Endocrinology & Metabolism, 86(4), 1489–1495.
9. Abbasi, B., Kimiagar, M., Sadeghniiat, K., Shirazi, M.M., Hedayati, M., & Rashidkhani, B. (2012). "The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial." Journal of Research in Medical Sciences, 17(12), 1161–1169.

Disclaimer: This newsletter is for educational and informational purposes only. It is not intended to provide medical advice, diagnosis, or treatment. Any guidance related to training, nutrition, supplementation, or lifestyle is general in nature and not a substitute for personalised medical advice. Always consult with a qualified healthcare professional before making changes to your health routine.