When you think about improving your sleep, where do you start? At the end of the day with bed time rituals ? Are you drinking a calming tea, doing a few stretches, supplementing Melatonin or taping your mouth before you go to sleep (yes, I am a mouth taper too, isn’t it sexy)?
But nowadays some people even use fancier things, such as Hyperbaric Oxygen Chambers, Sleeping Apps or pulsing Frequency Devices. But one, almost forgotten, most basic and free ingredient for a good night’s sleep is : EARLY MORNING NATURAL LIGHT EXPOSURE. I am not writing “SUNLIGHT” for a very good reason, because it doesn’t matter whether it’s a cloudy day.
Also, I’m not talking about just “getting outside a bit” during any time of the day. I’m talking about exposing yourself to specific light frequencies at a very specific window of the day to set your circadian rhythm (sleep-wake rhythm), your body’s
internal clock. And here’s the best part: You can start right away with this free natural resource, which doesn’t take any of your additional time as long as you consistently (habit stack) 10 minutes per morning. How you do it, I’ll explain below.
Cultivating a Habit of Morning Light
If you like to properly set your circadian rhythm, you need to get a regular dose of natural light in the early morning, meaning ideally within the first minutes after waking. This light exposure tells your brain: “The day has begun” which is gently stopping the production of melatonin (sleep hormone) and getting ready to be producing cortisol (“get-up-and-go” hormone). This light cue also sets a timer so that roughly about 14 hours later, your melatonin production kicks in again, helping you fall asleep easily and to sleep deeply at night.
If you already get at least 10 minutes of natural light in the morning and still struggle with sleep, there may be a few important parts that you are missing:
1) LIGHT SIGNALLING HAPPENS THROUGH YOUR EYES: You need to expose your eyes to natural light without anything in between - this means: Don’t wear sunglasses or even contact lenses or glasses as these significantly block important light frequencies ! And get outside ! Exposure through windows is significantly weaker and is not sufficient. Your eyes’ retina have special cells the ipRGCs (intrinsically photosensitive retinal ganglion cells) that are most sensitive to blue light. When they detect natural morning light, they tell your brain’s master clock in the hypothalamus - the SCN (suprachiasmatic nucleus) that the day has started. When you wear sunglasses the receptors in your retina don’t get the full spectrum of light - including the blue light rising in early morning sunlight - to signal and activate your master clock. (1) But, please be careful, you mustn’t look directly into the sun, which could be harmful for your eyes. It is sufficient to face the open sky.
2) TIMING: If you wake up late long after sunrise (due to late night work or night shifts), you are missing the less intense blue light wavelengths, which are key to gently signal your brain to slowly stop melatonin production for the day and to soon start cortisol production in healthy amounts. This creates a predictable hormonal rhythm, so your body “knows” that the day starts. There is a second super powerful light window which is called UVA Rise, which happens 30–90 minutes after sunrise (depending on location and season). When UVA wavelengths become part of the spectrum, alongside stronger blue light, both cues are reinforcing circadian signals. UVA light signals to the SCN in the hypothalamus to fully stop melatonin production and to start cortisol release. It also stimulates dopamine and serotonin production, boosting mood and motivation. It helps regulate thyroid function and metabolic processes. (2) It supports skin & immune health by triggering protective and Vitamin D optimisation mechanisms, just before stronger UVB light appears in the spectrum. UVA rise is highly depending on your location and season. For example, in August in Europe, UVA rise might happen around 7:30 am, while in winter it could happen only at around 9:30 am. Sunlight tracking apps like Circadian or MyCircadian help as you can find your exact sunrise, UVA and UVB times.
My Personal Wake-Up Call
When I moved back from sunny Singapore to Germany last year, I realised how much the shorter and darker days of autumn and winter affect my body. Since I became a brilliant sleeper in the past few years, I could hardly bear the fact that my sleep seemed on a decline. That’s when I started diving deep into circadian biology. I learned how much our bodies depend on light timing (not just light in general) to function optimally. I stopped checking my phone first thing in the morning, because it gave a wrong midday light signalling to my brain, and I began going outside right after sunrise, even if it was cold or cloudy.
On some days it was just 10 minutes on my balcony with my matcha. On others, I habit stacked it onto my yoga or trampoline practice in the garden. On some days I love to take a 30min walk first thing in the morning. Even under grey German skies, the light is strong enough to signal to my brain and reset my circadian rhythm. Eventually, my fantastic sleep came back and ever since I have started to build on my knowledge of light frequency therapy for the benefit of my patients.
How Do You Know That This Works?
Besides the many studies (3) that have been conducted in the field, have you ever notice how well you sleep on a beach vacation or camp holiday? That’s because you’re outside all day, syncing your circadian rhythm perfectly with the sun. Your brain is getting correct light signals all day from sunrise to sunset, and your circadian clock runs like a well-tuned instrument after a few days. When you are indoors under artificial light, you miss these cues, and your body can easily get out of sync. That’s why even a small daily dose of morning light can make a difference.
Real-World Evidence backs this up:
A 2024 study on professional athletes using wearable devices and standardised sleep and light assessments found that higher levels of morning and daytime outdoor light exposure were strongly associated with longer total sleep time and improved sleep indices (Stevenson et al., Nature and Science of Sleep). According to a 2025 randomized controlled crossover study by Osaka University, a 20min exposure to natural dawn light significantly reduced fatigue and improved morning alertness in students compared to no light. In another study seasonal reductions in natural daylight, especially in winter, were linked to later sleep and wake times in students (Dunster et al., 2023).
When people spend some days outside - sunrise to sunset - even if its just for a weekend, their internal clock shifts earlier, melatonin onset advances and sleep improves, even after a single weekend in natural light (Stothard et al., 2017). A week of camping with only natural light and no electronics advanced participants’ internal clocks by about two hours, aligning them more closely with the natural solar cycle (Wright et al., 2013).
Clinical evidence shows that morning light is the most potent Zeitgeber for advancing delayed circadian rhythms, improving sleep timing and quality. Light therapy in the morning has demonstrated benefits in shift workers, patients with insomnia, and individuals with delayed sleep–wake phase disorder, with natural morning light exerting stronger effects than standard indoor electric lighting (Blume et al., 2019).
How to Fit This Into Your Busy Schedule:
You don’t have to overhaul your schedule, just be creative and most importantly habit-stack as everyone leaves the house at some point, everyone drinks, eats, exercises. Here are some things I do and recommend to my clients :
1. Do a few morning stretches outside right after waking (5min) 2. Do your morning sports / activity program outside (30min)
3. Drink your coffee or tea outside in the morning (10min)
4. Have your breakfast outside (15min)
5. Take your bicycle to work (30min)
6. Walk your kids to school or to the bus stop (30min)
7. If you drive to work or your kids to school, roll down the window at every traffic light (10min)
8. If you are working from home, work with an open window or open it a few times during the morning hours (30min -120 min)
9. If working at the office, schedule two “light breaks” in the morning (each 10min) (4)
10. Take one of your work calls outside (30min)
11. Take one of the meetings with your colleagues standing by an open window (30min)
12. Send this blogpost to your friends to get an accountability partner as you want to make this happen,
13. Send this blogpost to your colleagues to make it really happen and include at least one “light break” per morning in your busy schedule.
Bottom Line
If nothing else has improved your sleep, try starting with the foundation - morning LIGHT signalling - it’s free, simple and scientifically proven.
1. Unfiltered / unblocked sunrise light resets your master clock.
2. Later morning unfiltered /unblocked UVA rise light kicks off the day by suppressing melatonin & balancing hormones for better mood, metabolism, skin & immune system.
3. Track your changes in a diary ! Note how much time you spend outside and at what times! Watch your sleep, mood, metabolism, mental clarity and energy improve over the weeks and refine your natural light habits.
The Flip Side Matters Too: What about evening light?
There’s a whole other story about evening light exposure and how to increase your melatonin production after sunset.
Especially in the winter months, where it is still dark outside when you wake up and where sunrise happens while you are at work.
If you like to know more about how to team up with the dark hormone melatonin, join my upcoming “Winter Glow” Masterclass (22 €) - happening on 6th November, 2025 - I will provide the bigger picture and best strategies for the upcoming season. Write me on WhatsApp (015224915716) or go to my website to sign up.
If you like this content, sign up for my newsletter to receive tipps & tricks to relieve stress, improve your sleep & feel radiantly alive this winter: www.claudiavonuckermann.com
About the author:
Claudia von Uckermann is a Somatic Therapist and Licensed Naturopath for Psychotherapy based at Lake Starnberg, Germany. She guides high achievers back into the present moment, helping them to reconnect with their bodies and inner compass through yoga and sound healing. Claudia has developed Somatic Release & Reprogramming techniques and her signature SoulFace Method™ , guiding her clients into a life that feels as good as it looks. She poses the question: “What if, you become the most relaxed person in the room - the one who holds the highest power through presence and ease?”
Footnotes:
(1) This master clock is connected to every organ, every gland and the autonomous nervous system meaning it orchestrates your body functions, the production of all hormones, neurotransmitters and it regulates not only your sleep-wake cycle, but your metabolism, nervous system and mood as well.
(2) Circadian and Metabolic Effects of Light: Implications in Weight Homeostasis and Health: https://pmc.ncbi.nlm.nih.gov/articles/PMC5653694/
(3) See references to evidential studies and further reading recommendations on the science behind natural light frequency therapy in the following:
a. Blume, C., Garbazza, C., & Spitschan, M. (2019). Effects of light on human circadian rhythms, sleep and mood. Somnologie, 23(3), 147–156.https://doi.org/10.1007/s11818-019-00215-x
b. Dunster, G. P., Hua, I., Grahe, A., Fleischer, J. G., Panda, S., Wright, K. P., Vetter, C., Doherty, J. H., & de la Iglesia, H. O. (2023). Daytime light exposure is a strong predictor of seasonal variation in sleep and circadian timing of university students. Journal of Pineal Research, 74(2), e12843.https://doi.org/10.1111/jpi.12843
c. Wright, K. P., McHill, A. W., Birks, B. R., Griffin, B. R., Rusterholz, T., & Chinoy, E. D. (2013). Entrainment of the human circadian clock to the natural light-dark cycle. Current Biology, 23(16), 1554–1558.https://doi.org/10.1016/j.cub.2013.06.039
d. Stevenson, E. J., Lastella, M., Willoughby, S., Davy, R., Vlahoyiannis, A., Osei-Tutu, K. B. A., Halson, S. L., & Sargent, C. (2024). Higher levels of morning and daytime light exposure associated with positive sleep indices in professional team sport athletes. Nature and Science of Sleep, 16, 1209–1220.https://doi.org/10.2147/NSS.S471017
e. Osaka Metropolitan University (2025, February 7). Natural dawn light reduces morning fatigue: Just 20 minutes of natural light before waking significantly reduced grogginess and improved alertness.https://www.omu.ac.jp/en/info/research-news/entry-80986.html
f. Stothard, E. R., McHill, A. W., Depner, C. M., Birks, B. R., Moehlman, T. M., Ritchie, H. K., Guzzetti, J. R., Chinoy, E. D., LeBourgeois, M. K., Axelsson, J., & Wright, K. P. Jr. (2017). Circadian entrainment to the natural light-dark cycle across seasons and the weekend. Current Biology, 27(4), 508–513.https://pmc.ncbi.nlm.nih.gov/articles/PMC5335920/
(4) When smokers are allowed to take a smoke break, why don’t we all start taking 1-2 light breaks at the office every morning, especially since our performance will increase?
(5) Adolescents with a smartphone sleep less than their peers Angélick Schweizer, André Berchtold, Yara Barrense-Dias, Christina Akre , Joan-Carles Surishttps://doi.org/10.1016/j.adolescence.2016.05.003
Claudia von Uckermann
@guest-claudia-von uckermann-1761107917082
