I need to tell you about a pattern I keep noticing. And once I point it out, you’ll probably recognise it.
Women in their late 30s to mid-50s with significant responsibilities—whether managing teams, running businesses, homeschooling kids, or juggling multiple demanding roles—all describing the exact same afternoon experience.
“By 3pm, I’m just trying to look engaged in meetings. My brain’s foggy. I’m nodding along, but I’m not really there. I’m terrified someone’s going to notice I’m not as sharp.”
They’ve been trying hard with diet & lifestyle - often tracking everything, eating organic, meal prepping, taking high-quality supplements, and even working with functional medicine doctors.
AND they’re drinking three coffees a day just to function. Sometimes four or five.
“Is this just what my getting older feel like? Have I lost my edge?”
And that question—that quiet terror underneath—I hear it constantly.
The fear that they’re declining. That their capability is slipping. That this is permanent.
But here’s what I want you to understand:
Your capability hasn’t declined. Your circadian rhythm is off.
And there’s a BIG difference between those two things.
The Afternoon Crash Is a Morning Problem
Here’s what most people don’t realise: That 3pm crash? It probably started at 7am.
Not at lunch. Not when you had that second coffee. At 7am, when your circadian rhythm didn’t receive the signal it needed to set your energy for the entire day.
Let me explain what I mean.
During my training at the Institute for Optimum Nutrition, I learned about something called the cortisol awakening response.
It’s this really distinct physiological event—a sharp increase in cortisol that happens about 30-45 minutes after you wake up.
This isn’t just cortisol gradually rising. It’s a sharp spike. A physiological boost designed to prepare your body for the metabolic demands of the day.
When that morning cortisol spike happens properly—at the right time, with the right intensity—your body is primed for efficient energy utilisation throughout the entire day.
Your mitochondria (energy factories in your cells) get the message: “It’s daytime. Produce energy. We need to be alert and capable.”
Your metabolism is ready. Your brain is sharp. Your insulin sensitivity is optimised.
But when that morning cortisol peak is weak or delayed?
By afternoon, your cortisol has dropped too low too early. And when cortisol drops below a certain threshold, you feel exhausted, get brain fog, heavy eyelids. That “I need to lie down right now” feeling.
So the afternoon crash is often a morning problem.
If your cortisol didn’t spike properly at 7:30am, it’s running on empty by 3pm.
What Controls the Cortisol Awakening Response?
Your cortisol awakening response is controlled by your circadian clock. Specifically, by your suprachiasmatic nucleus—your master clock in your brain.
And that clock is set primarily by light exposure.
When you get bright outdoor light in the morning—within the first hour or two of waking—something specific happens at a cellular level.
The light hits specialised cells in your eyes called intrinsically photosensitive retinal ganglion cells (let’s just call them ipRGCs).
These aren’t the cells that help you see images. They’re photoreceptors designed specifically to detect environmental illumination and communicate that information to your brain’s master clock.
When morning sunlight hits these cells, they send signals directly to your circadian clock saying: “It’s daytime. It’s morning. Time to increase cortisol production.”
That signal triggers the cortisol awakening response. That spike 30-45 minutes after waking.
That spike then sets your energy trajectory for the entire day.
But when you don’t get that light signal—when you’re inside from the moment you wake up, looking at artificial light instead of natural daylight—that signal doesn’t happen properly.
Your cortisol might rise gradually instead of spiking. Or it might spike late. Or not enough.
Your circadian clock doesn’t receive the information it needs.
And then by afternoon, your cortisol has dropped too low. And you crash.
My Ireland Rain Experiment
Some years ago, I was experiencing exactly this pattern.
I was drinking coffee at 7am, 11am, 3pm. Sometimes a fourth one after dinner because I had work to do and my brain wouldn’t cooperate.
I was eating better than I ever had. Prioritising nutrition. Trying to get enough sleep (though this was tricky sometimes with small children). But I was doing all the things I was “supposed” to do.
But I felt worse than when I was eating pizza and staying up until midnight.
I remember being in an afternoon call—maybe my third or fourth of the day—and someone asked me something. And I knew I knew the answer. I could feel it there, just out of reach. But I couldn’t access it.
My brain was foggy, and slow, Like trying to run through water.
And I remember thinking: “I used to be good at this. What’s happening to me?”
That thought terrified me. Because if this was permanent—if this was just my new normal—what did that mean?
So when I learned about the cortisol awakening response and morning light exposure during my training, I decided to test it.
I live in Ireland. And when I started implementing morning light exposure, it was February.
Grey. Drizzly. Properly miserable weather.
I remember the first morning. Standing in my garden at 7am in my dressing gown. In the rain. Looking absolutely ridiculous.
I couldn’t see the sun. It was completely overcast. Just grey sky and drizzle.
And I’m standing there thinking: “What am I even doing? This can’t possibly be doing anything. There’s no sun. It’s grey. It’s raining.”
I felt absolutely ridiculous.
Week one, every single morning, I genuinely thought: “This is pointless. The research must be wrong. Maybe it only works in sunny climates. This isn’t doing anything”.
I almost stopped multiple times.
Week two, Tuesday morning. It’s bucketing down. Properly pouring. And I’m standing at my back door thinking: “This is mental. I’m standing in the rain because I read some research about photoreceptors”.
I almost didn’t go out. I thought: “It’s not working anyway. I don’t feel any different. I still need three coffees. Maybe this only works for people in sunny climates”.
But something—stubbornness, maybe, or maybe just desperation—made me go out anyway.
I stood in the pouring rain for 15 minutes. Soaking wet. Feeling absolutely ridiculous. Convinced it was pointless.
Week three, Wednesday morning, something shifted.
I woke up and I felt... different. Not dramatically different. Not like a switch had flipped. But noticeably more alert.
Like my body had switched on properly.
I got out of bed without hitting snooze. Not because I forced myself. Just because I was... awake.
That afternoon, I was in a call around 3pm—normally my worst time—and I realised halfway through: I’m fully present. I’m tracking the conversation. I’m contributing ideas.
And I thought: “Wait. I haven’t had a third coffee. And I don’t need one.”
By week four, I hadn’t needed that third coffee in over a week. Some days I didn’t even need the second one.
My afternoon energy was more stable, the crashes were less severe, and I could focus in afternoon meetings.
I felt like myself again.
Why It Works on Grey Days
Here’s what the research shows: Even on a heavily overcast day, outdoor light provides orders of magnitude more lux—that’s a measure of illuminance—than typical indoor lighting.
Those specialised light-detecting cells in your eyes? They’re uniquely adapted for detecting gross environmental illumination.
Even when it’s grey and overcast, outdoor light delivers the necessary intensity for these cells to fire correctly and send the signal to your circadian clock.
Our biological systems evolved to receive high-intensity environmental light signals. That’s what entrained our circadian rhythms for millions of years.
Indoor lighting—even bright LED bulbs, even “daylight spectrum” bulbs—they don’t provide the same intensity or spectral composition.
Natural outdoor light provides a full spectrum. Blue light, red light, infrared. The entire electromagnetic spectrum that our biology expects and responds to.
So yes. Even on grey mornings. Even in the rain. Even when you can’t see the sun.
It’s still significantly brighter outdoors than indoors. And your biology responds to that difference.
What to Expect Week by Week
If you start implementing morning light exposure, here’s a realistic timeline based on what I experienced and the pattern I see repeatedly in my clients:
Week 1: You probably won’t feel different yet. You might think it’s pointless. That’s normal. Your circadian rhythm is recalibrating. The changes are happening at a cellular level, but they’re not obvious yet.
Week 2: Still might not feel much. You might be tempted to quit. (I almost did.) Keep going. Your body is learning to trust the signal.
Week 3-4: This is typically when shifts happen. Maybe you wake up more alert one morning. Maybe you realise you’re not as desperate for that third coffee one afternoon. The changes are subtle but real.
Week 6-8: Afternoon energy becomes noticeably more stable. You’re not fighting to stay awake in meetings. Your brain fog is clearing. You feel more like yourself.
The key is consistency. Your body needs to know: “This is the new pattern. Morning light happens every day. We can trust this.”
If you do it for three days, skip four days, do it again for two days—your body stays confused.
But if you’re consistent for 6-8 weeks? Your circadian rhythm strengthens. And afternoon crashes become significantly less severe.
The Simple Protocol
Here’s what actually works:
Get outside within 1-2 hours of waking. 10-15 minutes minimum. 20 minutes is better.
No sunglasses. No windows. Actual outdoor light exposure.
Even on grey days. Even in the rain. Even when it feels ridiculous.
Your circadian clock needs that signal. Your cortisol awakening response needs that trigger.
And your afternoon energy will reflect what happened—or didn’t happen—at 7am.
You Haven’t Lost Your Edge
So if you’re needing multiple coffees just to function, if by 3pm your brain feels foggy and you’re desperately trying to look engaged, or if you’re terrified someone’s going to notice you’re not as sharp…
This isn’t capability declining. This isn’t “just getting older.” This isn’t permanent.
This is circadian misalignment. And circadian alignment can be corrected.
Your biology is designed to function brilliantly. Your mitochondria are designed to produce stable energy. Your cortisol rhythm is designed to keep you alert and focused.
But your body needs specific signals to do this.
And the most foundational signal? Morning light exposure.
Even in grey climates. Even in February. Even in the rain.
Because I got myself back. And you can too.
📥 Want to understand the 3 foundational circadian signals your body needs?
I created a free guide that breaks down exactly what’s missing and how to start correcting it.
Grab “3 Hidden Signals Your Body Is Missing” here → francesnorgate.com/resources
And if this resonated, share it with someone who needs to hear this. Forward this email. Send them the link. Help them understand: they haven’t lost their capability. Their signals are just off.
Thank you so much for reading - see you next week,
Frances
P.S. I’m always happy to answer questions - so feel free to contact me. It also helps me know what you’re all interested in, so I can make more content on those topics.
