00:00
Please pause here.
00:15
Welcome back to Pause Here, where we delve into the art and science of breathing to improve our daily lives.
I'm your host, Sarah, here to guide you through the science and simplicity of breathing, meditation and relaxation techniques that can transform your day, your health and even your sleep.
Now, here's something we don't think about enough.
Sunlight is basically the most underrated health tool on the planet.
It regulates your mood, your sleep, your immune system, even your memory.
It helps your body make vitamin D, sets your internal clock and gets your brain to produce more serotonin.
That's the neurotransmitter that helps you stay focused and calm.
In short, light affects almost everything.
And most of us barely notice it, until we're not getting enough.
01:11
In this episode, we're going deep on what sunlight actually does to us.
Physically, mentally, emotionally, and why the kind of sunlight you get, and when you get it, can change how you feel and function in some surprising ways.
This episode, we'll explore how different parts of sunlight, UV, visible light, and even heat interact with your body and brain.
We'll look into what happens when we don't get enough light.
Think mood swings, sleep problems, and the winter blues.
We'll investigate why a sunbeam in Melbourne in January is totally different from one in Denmark in February, and why that matters.
And how design, geography, and even public health are rethinking our relationship with daylight.
So let's get started.
02:08
Let's start by talking about what sunlight actually is, and importantly, what it does for you.
It turns out sunlight isn't just brightness.
It's a kind of invisible data stream made of different wavelengths that hit your skin, your eyes, your brain, and trigger a bunch of fascinating biological reactions.
Think of it like a symphony, but instead of music, it's made up of ultraviolet light, visible light and infrared.
And your body?
It's the orchestra that responds.
We'll start with UVB.
That's the shortest, most energetic part of sunlight that doesn't get blocked by sunscreen or clouds very easily.
This is the light that helps your body produce vitamin D right in your skin.
No pills, no food, just sunlight, chemistry and some evolutionary brilliance.
And vitamin D?
It's not just about bones.
Research has linked vitamin D deficiency to increased rates of depression in adults.
It's also connected to immune function, inflammation and even brain health.
But here's the kicker.
UVB light only really shows up when the sun is high enough in the sky.
In winter, especially if you live above 37 degrees latitude, like New York, London or Copenhagen, UVB basically disappears.
Your body just can't make vitamin D from sunlight during those months, which helps explain some things like seasonal depression and why people feel so off during long winters.
03:45
After the UVB, we have the visible light, the stuff we can actually see.
This is the sweet spot of sunlight, and it's a major player in how your brain keeps track of time.
Visible light, especially blue light from the shorter ends of the spectrum, enters your eyes and signals a tiny structure in your brain called the suprachiasmatic nucleus.
That's the part of your hypothalamus that acts like your body's master clock.
So morning light exposure isn't just about waking up, it's actually setting your circadian rhythm, regulating your melatonin, your sleep hormone, and syncing up almost every other biological process, digestion, temperature, even your mood.
A study from the 90s found that just a small shift in when we get light exposure can totally throw off our circadian rhythms, leading to sleep problems, fatigue, and mood changes.
It's why people who spend all day indoors under dim or artificial lights can start to feel a little off, like jet lag, but caused by your own lighting.
04:52
Speaking of mood, this is where sunlight gets even more interesting.
Remember serotonin, the neurotransmitter that helps regulate mood, emotion, and attention?
A 2002 study found that sunlight exposure is directly linked to increased serotonin turnover in the brain.
More sunlight produces more serotonin, which produces a better mood.
That's a big part of why people feel more upbeat, alert, and emotionally stable during bright sunny days, and why cloudy, low-light periods can make us feel sluggish or low.
And this isn't just anecdotal, it's backed up by neurochemistry.
Your brain is literally responding to how much light it gets.
05:38
Lastly, we've got infrared light, the warm, cosy part of sunlight that you feel on your skin.
This one's a bit more subtle, but still important.
Infrared light doesn't trigger chemical changes like UVB, or shift your circadian rhythm like blue light, but it does promote circulation, relaxation, and even helps reduce inflammation in certain contexts.
Some studies suggest that exposure to natural warmth from sunlight, especially in the mornings, might help lower cortisol, your stress hormone, and promote a sense of calm.
So yes, that moment when you step into a patch of sunlight and feel warmed up from the inside out, more relaxed, it's not just in your head, it's in your blood vessels.
Sunlight isn't just one thing, it's a complex mix of signals, and each part has a role.
UVB helps your body make vitamin D, visible light keeps your brain on schedule, and infrared, it gives your system a nice warm hug.
And all of this happens without you doing anything, just light and biology doing what it's done for thousands of years.
From the moment you wake up to the way you fall asleep, sunlight is setting the rhythm for your entire day.
07:04
All right, let's go global for a second.
Because here's a weird but true observation.
The sun in Bali feels totally different to the sun in Berlin.
It's warmer, yes, but it's also stronger, more intense, and way more biologically active.
And that's not just the vacation vibes talking, it's science.
Let's start with something called the UV index.
That's the scale used to measure how strong the ultraviolet radiation from the sun is at any given time and place.
On this scale, 0 to 2 is considered low, mostly winter in northern places like Denmark, Scotland, or parts of Canada.
Around 6 to 7 is considered high, and over 11 is extreme.
That's what you'll often see in Australia in the middle of summer.
A recent study looked at these regional UV differences and found that the composition of sunlight changes dramatically by location and season, and those differences actually change how sunlight affects your body.
In high UV zones, like Sydney or Cape Town in summer, UVB is abundant, which boosts vitamin D production, but also increases the risk of skin damage and even eye stress.
So, don't forget your sunscreen.
In places like Denmark or Alaska during winter, UVB is practically non-existent for months.
So, no matter how sunny it looks, your skin can't produce vitamin D.
So, you might see the sun, but biologically, your body isn't getting the same benefits.
08:44
This is also where culture meets climate in really interesting ways.
In parts of the world where the sun is strong, say, Spain, Mexico, and parts of the Middle East, you'll often find cultural rhythms that work with the sun.
People stay out of the heat during midday, take siestas and spend mornings and evenings outdoors when the light is softer but still biologically effective.
But in northern countries, where sunlight is scarce in winter, you'll find things like higher rates of seasonal affective disorder, more use of artificial light therapy lamps and even mental health trends that follow the daylight curve, like depression and fatigue spiking in winter and dropping in spring.
This isn't just a mood thing, it's circadian and neurochemical.
Low light means less serotonin, less melatonin regulation and a higher chance of circadian drift, which makes people feel tired, unmotivated and just kind of off.
09:49
Now, here's where it gets really interesting and a little frustrating.
Not everyone gets the same access to sunlight even within the same city.
Think about it.
If you work overnight shifts, your circadian system is completely flipped.
If you live in a high-rise city with small windows or in housing where the sun barely comes in, you're definitely missing out.
If you're older and spend most of your time indoors, your light exposure can drop dramatically.
And low-income neighbourhoods often have less access to green space, fewer outdoor safe areas, and less sun-friendly building design.
This is sometimes called light poverty.
It's not just about convenience, it's about our health.
Some public health researchers are now calling for daylight to be treated as a basic human need, not just a lifestyle bonus.
So next time you hear someone say, just go outside, it's worth remembering that not everyone can, and even if they can, what kind of light they're getting can make a big difference.
So here's a question for you.
When's the last time you noticed the light change where you live?
Not just the weather, but the light itself.
The angle, the colour, the strength?
Did you wake up to bright sunlight or soft blue overcast?
Did you get any real daylight at all?
That kind of awareness, not just how much light we're getting, but what kind, is actually a big part of protecting our health in the long term.
11:30
So far, we've talked about what sunlight does inside your body, boosting vitamin D, regulating sleep, improving mood.
But now let's zoom out and ask a different kind of question.
What happens when we design our buildings, the places we live, work and heal, with sunlight in mind?
Here's what the research says.
Natural light in indoor spaces can speed up recovery, reduce pain, improve focus and even raise test scores at schools.
It's one of the simplest design tools we have, and it's weirdly underrated.
12:06
Let's start in the hospital.
Back in 1984, environmental psychologist Roger Ulrich published a now famous study showing that patients recovering from surgery in sunlit rooms recovered faster, needed less pain medication and had shorter hospital stays compared to patients in darker rooms.
Even when everything else was identical.
Let that sink in for a moment.
Just the presence of a window with a view of daylight made a measurable difference in healing.
Since then, dozens of studies have backed this up.
Natural light helps regulate patient sleep-wake cycles, reduces anxiety and lowers stress hormones, all of which improve immune function and recovery.
So hospitals around the world have started to respond.
You will now see newer facilities using large windows, glass ceilings and even daylight corridors in surgical and ICU units.
This is not just for the aesthetics but for actual health outcomes.
13:10
Now let's talk schools.
A major study in 2003 looked at more than 20,000 students across three US school districts.
And what they found was kind of wild.
They found that students in classrooms with more daylight progressed up to 25% faster in maths and reading than those in classrooms with less light.
This is because natural light supports alertness and reduces visual fatigue.
It helps keep circadian rhythms aligned so students are more awake and ready to learn.
And it simply makes the environment feel more comfortable, which lowers stress and increases focus.
And it's not just kids.
Offices with access to natural light report higher productivity, lower absenteeism and better mood scores across the board.
Basically, sunlight is cognitive fuel and we often build right past it.
14:07
So why is natural light so powerful in indoor spaces?
Here's what's happening.
Your eyes contain special light-sensitive cells, separate from those used for seeing, that send signals to your brain's master clock.
Remember from earlier, the suprachiasmatic nucleus?
When you're exposed to bright full-spectrum daylight, your body knows it's daytime.
It suppresses melatonin, boosts alertness and helps balance mood-related chemicals like serotonin and dopamine.
That's why people tend to feel more awake and optimistic in spaces with natural light, and why people in windowless offices often report feeling groggy or disconnected from time.
There's even a growing design movement around this.
It's called neuroarchitecture, designing spaces based on how our brains and bodies respond, and biophilic design, building with natural elements like sunlight, greenery and airflow.
A recent study showed that light-friendly design in healthcare and education environments reduced stress, improved emotional regulation, and even supported neuroplasticity, the brain's ability to adapt and grow.
We're literally building spaces that make people feel better, just by letting the sun in.
And it's not just hospitals and schools, your own home can work the same way.
Simple shifts like spending your morning near a sunny window, arranging your workspace to face daylight, using sheer curtains to diffuse, not block, sunlight, can all improve your mood, help regulate your sleep, and reduce fatigue, even if you're not stepping outside.
And in winter or low-light environments, tools like full-spectrum daylight bulbs, light therapy lamps, and light alarms can help simulate those same benefits.
You don't need a sunroom.
You just need to let the light in.
Sunlight isn't just a backdrop.
It's an active part of how our spaces can support our health.
16:16
We've talked about what sunlight does for our brains and bodies.
But what about when it disappears?
Because here's the thing, we are not built for endless winters indoors.
Our biology is tuned into rhythms of light and dark.
When that rhythm goes out of sync, especially during long dark winters or in low-light environments, we start to feel it.
In our energy, our mood, our sleep, our motivation.
So, let's unpack what's really happening when light goes missing, and what science says we can do about it.
16:52
Let's start with something that you've probably heard of, seasonal affective disorder or SAD.
SAD isn't just feeling a little off when it's cloudy, it's a diagnosable form of depression that hits during specific times of the year, usually in late fall and winter, and lifts as the days get longer.
Symptoms can include low energy, trouble sleeping or oversleeping, changes in appetite, feeling sluggish, hopeless or withdrawn.
And it's not rare.
According to the American Psychiatric Association, around 5% of adults in the US experience seasonal affective disorder, and many more deal with subclinical seasonal mood changes, sometimes called the winter blues.
But what causes it?
One major factor, lack of sunlight.
Specifically, lack of bright morning light that our bodies rely on to regulate our internal system.
17:54
Here's how it works on a biological level.
Light controls melatonin.
Melatonin is your sleep hormone.
Your brain starts releasing it when it gets dark.
If your mornings are too dim or your days don't include real daylight, your melatonin cycle can get messed up.
The result?
Daytime sleepiness, nighttime insomnia, or both.
Light also affects serotonin.
As we mentioned earlier, serotonin helps regulate mood, focus and emotional balance.
Studies show that bright light exposure boosts serotonin levels in the brain.
Without light, that serotonin activity drops, and with it, mood stability.
Lack of light also results in a disrupted circadian rhythm.
Your circadian rhythm is your 24-hour internal clock, tied directly to light and dark signals.
When you don't get consistent bright light in the morning, that rhythm can shift out of sync, leading to fatigue, poor concentration, and emotional flatness.
Basically, your body and brain start operating in the wrong time zone, even if you haven't gone anywhere.
19:06
This isn't just about winter or geography.
People who spend most of their time indoors, under low artificial lighting, experience similar effects.
Office workers, shift workers, students in windowless classrooms, hospital patients, even gamers, remote workers, or just anyone binge-watching indoors for hours.
Low-light environments don't give you enough lux.
That's the unit for light intensity.
They also don't contain the full light spectrum that your body responds to, and they don't help your brain know what time it is.
This leads to what researchers call emotional fatigue, a low-grade, hard-to-pin-down feeling of mental fog, irritability, and low motivation that builds up over time.
It's like background noise in your nervous system, and a big part of it comes back to a simple lack of light.
20:00
But here's the good news.
Science has a workaround, and it works really well.
It's called bright light therapy.
A 2005 meta-analysis looked at dozens of clinical trials and found that light therapy was highly effective treating both seasonal depression and even non-seasonal forms of depression.
Here's how it works.
Patients sit near a light therapy box, usually around 10,000 lux, for 20 to 30 minutes each morning.
The light mimics natural outdoor light and helps reset the circadian rhythm.
It increases serotonin activity and reduces melatonin levels at the right time of day.
It's basically sunlight on demand without the UV rays.
Light therapy is now widely used in clinics, workplaces and homes.
Some new alarm clocks even use gradual light increases in the morning instead of sound, simulating a sunrise, which can help reset sleep cycles naturally.
21:07
If you live somewhere with long winters, or if you work indoors for most of the day, this isn't about moving to the equator, although sometimes tempting.
It's about reframing how we think about light.
Light isn't just a background condition, it's a form of nourishment.
Your brain and body literally depend on it to function properly.
So what would happen if we treated light like we treat food or sleep?
You'd get bright light in the morning, not just blue light from your phone.
You'd prioritise time outside, even on overcast days.
You might use light therapy the same way you take supplements, seasonally, or when you need extra light support.
And you'd recognise that feeling off in winter isn't weakness, it's biology.
So what would happen if you treated light like nourishment instead of background?
Would you rearrange your morning routine?
Open the blinds earlier?
Maybe step outside at lunch instead of scrolling in the break room.
Because it's not just about sunshine and vibes.
It's chemical, hormonal, neurological, and it's fixable.
22:24
So now we know that sunlight isn't just decoration.
It's a biological input, like food, water and sleep.
So the question is, how do we actually use that knowledge in our everyday life?
Here are a few simple ways to design a life that works with light instead of around it.
Get around 20 minutes of morning light, outside if possible.
This is the easiest and most impactful change you can make.
Getting bright, natural light within an hour of waking helps regulate your circadian rhythm, boost serotonin, suppress melatonin at the right time, improve alertness, mood and sleep quality later that night.
It doesn't have to be a jog or a full hike.
Even sitting outside with your morning coffee, walking your dog or standing near an open window on a sunny morning can count.
Cloudy days still help.
It's about light intensity, not just sunshine.
23:24
You can rearrange your space around light.
Think about where the light actually lands in your home or workspace, and how you can position yourself to get more of it during the day.
A few easy changes are to move your desk near a window.
Face the window instead of having it behind you.
You can also use mirrors to bounce light into dark corners.
Swap heavy blackout curtains for sheer ones in rooms you use during the day.
You don't need to knock your walls down.
Try working with what you've got and go from there.
If you live in a place where winters get dark, or if you work long hours indoors, full-spectrum bulbs and light therapy lamps can help simulate the benefits of natural light.
Look for a 10,000 lux lamp for morning use, daylight or full-spectrum bulbs for lamps in key areas, and maybe a gradual sunrise alarm to wake up more naturally.
These tools don't replace sunlight completely, but they can nudge your system in the right direction.
24:28
Try taking sun breaks like you would water breaks.
We're used to the idea of taking a coffee break or filling up a water bottle, so why not take a light break?
Every few hours, try stepping outside, even for a few minutes.
Look out a window, let the light hit your eyes and skin.
Stretch in a bright sunny spot.
These small light hits throughout the day add up, and they help maintain a healthy rhythm, even in artificial environments.
It's not about being outdoorsy, it's about being light literate.
We spend so much time thinking about productivity, nutrition, mindfulness, even supplements, and sometimes completely overlook the thing that actually sets our system, the light right outside.
So give your body what it's looking for, a little bit of light, a little bit earlier, a little more often.
25:28
Today, we've explored and learned that sunlight isn't just something we feel, it's something our bodies use and need.
It boosts our mood, syncs our sleep, strengthens our immune system, helps us heal and makes us sharper and more focused.
And the kind of light we get, how much, when and where, matters.
The morning sun in Sydney isn't the same as a grey afternoon in Stockholm.
Some people get plenty of daylight without thinking about it.
Others, because of geography, work schedules, buildings or the season, barely get any at all.
And that's not just a personal issue, it's a public health issue.
But the good news is, once you're aware of how light works, you can start to build habits and spaces that support your brain and body better.
Whether it's stepping outside earlier, moving your desk or grabbing a full-spectrum light in winter, small changes can shift a lot.
So this week, treat light like it's part of your health, because it is.
But don't forget your sunscreen.
26:39
Thanks for pausing here with me today.
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27:09
Next time on Pause Here, we're diving into one of the simplest things you can do to calm your body fast.
Breathe, specifically the 4-7-8 count pattern, a technique that's been shown to slow heart rate, reduce anxiety and help with sleep.
We'll break down what actually happens in your nervous system when you change how you breathe, how this rhythm activates your parasympathetic response, and why timing your inhales and exhales matters more than you think.
Whether you're looking to unwind before bed, reset after a stressful meeting, or just breathe better, the next episode's for you.
I can't wait to bring more peaceful pausing points and practical tips your way next time.
As we close today's episode, if you have a few more minutes to stick around, I invite you to join me for a short sunlit meditation.
28:11
Sunlit Meditation
Wherever you are right now, indoors, outside, travelling or sitting still, let's use this moment to simply notice the light.
If you can, find a patch of sunlight, a window, a warm spot on the floor, the back of your hand.
If there isn't any where you are, that's completely okay.
You can just imagine it.
That slow, golden warmth of summer light, the kind that softens everything.
Let your body get comfortable.
No need to sit a certain way, just settle in.
Let your jaw unclench.
Let your shoulders drop.
Let your hands rest gently.
Take a slow, deep breath in through your nose, and gently out through your mouth.
Let your breath settle on its own.
No need to control it.
29:23
Now picture sunlight, either real or imagined, beginning to land on your skin.
Maybe your face, maybe your hands, maybe your legs.
Wherever it is, just notice how it feels.
Warm, soft, steady.
Not doing anything flashy, just quietly showing up.
Imagine that light moving down your body like a slow, warm filter across your forehead, down through your jaw and neck, softening your shoulders, warming your chest, through your arm and down to your fingertips.
Let it settle into your stomach.
Let it melt through your hips and thighs, your knees, your calves and all the way to your feet.
You don't have to do anything.
Just let the light settle where it wants to.
30:42
Now, bring your attention to your breath.
As you inhale, imagine you're breathing in light, that golden, steady, late-afternoon kind of light, filling your ribs, your lungs, your chest.
As you exhale, let any tightness go, like shadows softening under the sun.
Inhale, let the light in.
Exhale, let everything soften.
Just for a few rounds, stay with that rhythm.
Inhale, sunlight.
Exhale, tension.
31:33
Let everything get a little quieter now.
Notice the sounds around you, the air on your skin, the way the light hits the floor, or the walls, or maybe nothing at all.
This is a moment of stillness, and you're in it.
You don't have to hold on to it, just know it's there.
Just like the light, even when you're not thinking about it.
Take one last deep breath in, and a long breath out.
If your eyes are closed, slowly let them open.
Let the world return gently into focus.
32:25
Whether you're stepping into sunshine, or soft indoor light, take a little of this pause with you.
Until next time, breathe deep, pause here, and shine bright.
