Less daylight, a changing sleep rhythm and more stress. Here’s what happens in our bodies in autumn – and what can help us get our energy back.

Maybe you know that feeling in September:

Summer isn’t really over yet, but suddenly everything feels different. It gets light later in the morning, the evenings become shorter, and the energy that seemed to come so naturally during summer starts to fade.

At the same time, the calendar fills up again. The holidays are over, the kids are back at school, projects are picking up at work, and appointments start piling up. Within just a few days, the more relaxed summer mode turns back into everyday life.

So it’s hardly surprising that some people feel more tired in September.

“Autumn fatigue” is not a medical diagnosis. Nevertheless, there are several understandable biological and psychological factors that can contribute to this feeling.

Your body notices that the days are getting shorter

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Light is one of the most important cues for our internal clock. The so-called circadian clock coordinates numerous processes in the body, including sleep and wakefulness, body temperature, hormone production, metabolism and many others. Its most important external cue is the light-dark cycle – and this changes quite noticeably from September onwards.

The sun rises later and sets earlier, and the amount of time we spend in natural daylight becomes shorter. On top of that, we often get even less daylight in everyday life: we drive to work, spend most of the day indoors and only leave again when it is already getting dark outside.

Yet daylight is considerably more intense than artificial indoor lighting.

Our internal clock does not function completely independently of the seasons. It is influenced primarily by light. And when the length of the day and our exposure to light change, the timing of our circadian rhythms can also shift. It is therefore not simply about the fact that it gets dark earlier in autumn. What matters is also how much daylight we actually get – and when.

This does not mean that our bodies suddenly start functioning “incorrectly” in autumn. They are responding to a changing environment.

September often brings not only less light, but also more stress

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After the summer months, many people return to a full schedule within a very short period of time. More appointments. More decisions. More responsibilities. More demands to be available.

Anyone with a lot of professional responsibility and/or school-age children will probably know this transition well. During summer, the calendar may have been a little more relaxed. And then suddenly it’s September, and five different projects all need your attention at the same time.

Our stress system is not inherently a bad thing. Activation of the so-called HPA axis – the connection between the hypothalamus, pituitary gland and adrenal glands – is part of a normal adaptive response in the body.

In the short term, this activation helps us stay alert and perform effectively. It becomes more problematic when there is hardly any recovery following periods of activation.

Chronic or recurring stress can affect sleep, mood, appetite and subjective feelings of exhaustion, among other things. And this is where an interesting connection with the gut begins.

Stress doesn’t just stay in your head

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The gut and brain communicate continuously via nerves, hormones, immune processes and metabolic compounds through what is known as the gut-brain axis. This communication works in both directions.

Psychological stress can affect gut function and the microbiome. At the same time, the gut communicates with the brain through nerves, hormones, immune processes and microbial metabolites. This communication can influence processes involved in stress regulation, mood and cognitive function.

The microbiome is not a simple “stress barometer”, however, and no individual bacterium is automatically responsible for our mood. Research increasingly shows, though, that stress, the gut, the immune system and the brain are interconnected.

And this becomes particularly interesting when we add another factor: sleep.

Less light, more stress – and suddenly your sleep suffers

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Light is the most important external cue for our internal clock. Among other things, it influences the release of melatonin, which signals to our body that biological night is beginning. What matters is not only how much light we receive, but also when we receive it.

As the days get shorter, our natural light-dark rhythm changes. At the same time, especially during autumn and winter, we often spend a large part of the day indoors and therefore receive less bright daylight. This can affect the alignment of our internal clock.

Then there is stress: increased and prolonged activation of the stress axis can interfere with sleep. And poor sleep, in turn, can affect stress regulation. This can easily create a cycle of tension, less restorative sleep and tiredness the following day.

That’s why one thing is particularly important when it comes to our energy: sleep is not a break from everyday life. It is an active phase of regeneration for both body and brain.

Movement can bring your energy back

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As the days get shorter, physical activity often decreases automatically. The walk after work gets skipped, the bike stays at home more often, and the evening run turns into an evening on the couch.

Yet exercise can be particularly helpful when you feel tired. A large meta-analysis of 81 randomized studies involving more than 7,000 participants showed that regular physical activity can reduce fatigue while improving energy and vitality.

You don’t have to squeeze an additional workout programme into an already busy schedule. A brisk walk, cycling or regular strength training can already make a difference.

Even better: if you move your activity outdoors, you combine two factors that can easily become scarce in autumn – physical activity and daylight.

Energy also needs the right “building blocks”

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When life gets busy, food can quickly become an afterthought. Breakfast gets skipped, there is little time for lunch, and by the afternoon you are suddenly starving. Coffee and something sweet are often the quickest solution.

For a stable energy supply, however, our bodies need more than a short-term energy boost. Regular meals containing sufficient protein, vegetables, fruit, whole grains, legumes, nuts and seeds provide energy as well as a wide range of micronutrients.

They also provide a great variety of dietary fibre. This serves as food for our gut bacteria, which metabolize it into, among other things, short-chain fatty acids such as acetate, propionate and butyrate. These compounds are also interesting in the context of the gut-brain axis mentioned above.

You don’t need to follow a complicated “gut cleanse” to achieve this. Variety is more important than perfection.

Vitamin D is a seasonal factor

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Autumn also changes our vitamin D supply. Vitamin D is produced in the skin under the influence of UV-B radiation. During the darker months of the year, less UV-B radiation is available for this process.

Vitamin D deficiency can be associated with fatigue. However, this does not mean that every case of autumn fatigue is caused by vitamin D deficiency.

If you feel unusually exhausted for a prolonged period of time, I would therefore not recommend taking supplements simply on suspicion. Instead, possible causes should be discussed with a doctor. Depending on the individual situation, this may also include checking vitamin D status.

Small changes that can make a big difference in autumn

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You don’t need ten new routines in September. What matters much more is keeping in mind the factors that particularly affect your body at this time of year.

Get outside in the morning: Try to get some daylight as early in the day as possible, even when the sky is grey.

Schedule movement: Don’t wait for motivation to arrive. A walk or workout can be put in your calendar just like a work appointment.

Prioritize sleep: When everyday life gets busier again, sleep shouldn’t be the first thing to sacrifice. Consistent bedtimes and wake-up times can also help stabilize your circadian rhythm.

Allow yourself to take breaks: Not every free minute needs to be filled. Especially when the workload increases again in September, your nervous system also needs periods without input and demands.

When your energy drops during the day

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We all know those days when we haven’t had enough sleep, the working day seems particularly long, or concentration starts to fade by lunchtime. Coffee is probably the best-known solution. Caffeine can temporarily increase alertness and attention.

BOOST+ by Braingood also contains caffeine, sourced from guarana. One shot provides 80 mg of caffeine as well as glucose, B vitamins from sprouted buckwheat and elderberry extract – giving you an energy boost when you need it.

But there is an important caveat: a short-term boost in alertness can be helpful, but of course it cannot replace sleep. If tiredness becomes a constant companion, it is worth taking a closer look at the underlying causes.

A little support for the gut-brain axis

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Stress and sleep are closely connected to our gut. The microbiome is also involved in the communication between the gut and the brain.

A synbiotic such as BioMe+ combines five probiotic bacterial strains with the prebiotic fibres inulin and FOS, as well as magnesium. It therefore brings probiotics and prebiotics together in a single product.

BioMe+ is not a remedy for autumn fatigue. However, it can be a useful addition if you specifically want to support your microbiome and, in turn, your gut-brain axis.

Because ultimately, the foundation remains the same: nutrition, movement, sleep and a healthy approach to stress.

Recharging your energy also means saving energy

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As the days get shorter and everyday life becomes busier again, it is worth looking not only at the things that give us energy, but also at the things that drain it.

Maybe it’s an overloaded calendar. Constant availability. Too little sleep. Too little movement. Or simply the fact that, after summer, we immediately try to function at 100 percent again.

But our bodies need more than activity and performance. They also need enough time for regeneration.

More daylight. Movement. Good sleep. A varied, nutrient-rich diet. And, every now and then, consciously doing a little less.

Because energy doesn’t only come from what we give our bodies. It also comes from giving them the opportunity to recharge.

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About the author

Mag. Carmen Crepaz, MSc.
Nutritionist and Functional Health Coach
Master’s degree in Nutrition and Sport
www.carmencrepaz.com/blog