FIT THROUGH YOUR STUDIES: Rest and sleep as the key to learning success

In the first part of our series "Fit through your studies" we met the coordinator of university sports at Universität Würzburg and learned why small steps often make the biggest difference. This time, we're tackling a topic that probably every one of us knows: Stress.

Submission deadlines, revision periods, part-time jobs – sometimes university life simply seems never-ending. That's exactly when it's hard to find time for rest or exercise. Yet that's precisely what's crucial to staying productive, focused and balanced.

Dr. Andreas Petko explains how exercise helps reduce stress, why good sleep is so important and how you can recharge your mental battery with small habits.

Interview

Question: University life also means performance pressure, submission deadlines and part-time jobs, which is usually associated with stress. What role does exercise play in stress relief?

Stress is simply part of university life. And that's exactly where exercise can be a real game-changer. When we exercise, the body reacts like a natural valve: stress hormones like cortisol are broken down, whilst at the same time endorphins and serotonin are released – our natural mood boosters.

So exercise not only helps clear your head, but also releases inner tension. Even a short walk, a few stretches or a brief training session can help the body relax and the mind become clearer. It doesn't always have to be a full workout. Sometimes just a walk after a lecture or a quick run is enough to find your way back to calm.

I see exercise as a form of active self-care. It gives us energy and composure at the same time. Those who stay active regularly not only strengthen their muscles and cardiovascular system, but also their ability to cope better with pressure and challenges. So exercise doesn't just make you fit – it makes you resilient.

Question: Many people notice that they think more clearly and learn better after exercise sessions. What exactly happens in the body and brain, and how can you consciously use this effect for your studies?

The fact that you can think more clearly and learn better after exercise can now be well explained from a neurobiological perspective. Exercise increases blood flow to the brain, which means more oxygen and glucose are available. Both are essential for neuronal energy supply. At the same time, physical activity moderately activates the sympathetic nervous system, which stimulates the release of neurotransmitters such as dopamine, serotonin and noradrenaline. These messenger substances improve attention, mood and motivation – the factors that are crucial for learning.

Particularly interesting is the effect on the hippocampus region, which is considered the "learning centre" of the brain. Through exercise, the concentration of Brain-Derived Neurotrophic Factor (BDNF) increases there – a protein that promotes the growth and networking of nerve cells. BDNF is considered a kind of "fertiliser" for the brain that strengthens new synaptic connections and supports memory formation. Put simply, exercise improves the brain's "wiring" and thus learning and memory performance.

Study-based data shows that even moderate exercise measurably improves attention and memory performance. Sport becomes a natural learning booster.

Question: Sleep deprivation and caffeine are almost normal during exam periods. How important are rest and sleep really, and are there small habits that contribute to better recovery?

Sleep is not wasted time, but perhaps the most important learning phase of all. While we sleep, the brain tidies up, sorts information, deletes what's unnecessary and stores what's important. Particularly in the hippocampus and neocortex, stable connections form during this process – what we know as consolidation. Without this nightly "data backup", much of what we've learned stays in short-term memory and disappears again the next day.

When sleep is lacking, the brain doesn't just lose energy – it also loses order. Sleep laboratory data shows that even a single shortened night noticeably reduces memory performance. So whoever studies late into the night isn't learning more – they're learning worse.

Caffeine works by blocking adenosine receptors, those signal sites that report tiredness. In short: caffeine keeps the brain awake by making it think it's not tired. This works brilliantly as long as you enjoy it in the first half of the day. Later in the day, however, it often sabotages exactly what you actually need: sleep architecture and thus restorative sleep.

So sleep and caffeine are like a good team, as long as they know when it's their turn. Those who remember this learn more concentratedly, remember better and stay clear-headed even during stressful phases.

Question: What would an "optimal day" during exam period look like for you personally?

An optimal day during exam period starts for me with a consistent sleep rhythm. That means I get up at the same time every day. The body and brain love regularity. Right after waking up, I go outside for 10–20 minutes. Exercise and daylight in the morning are like a natural pick-me-up – they get the circulation going and signal to the body that the day has begun. If there's no sunlight outside, bright indoor light also helps stabilise the circadian rhythm.

After that comes a short exercise session. It doesn't have to be intense training – sometimes just light mobilisation or a few squats are enough to activate the muscles. Then I start my first learning phase, ideally in 30- to 45-minute blocks, followed by a short active break of 1–5 minutes. These little breaks keep the brain fresh and promote concentration. 2–4 such learning cycles in the morning are often far more effective than hours of continuous studying.

Nutrition also plays a major role. I make sure to eat light, balanced meals that don't affect blood sugar too much. Heavy, fatty foods or large portions quickly make you tired. After eating, I prefer to plan lighter tasks or move around briefly. This helps avoid the well-known "food coma".

In the afternoon, there are another 2–4 learning blocks, but I make sure to reduce intensity towards the evening. Learning is not a sprint – it's a marathon. Once your head is full, it's more sensible to actively do something else rather than plough on mindlessly. A longer exercise session in the afternoon or early evening is the perfect balance for me. It helps break down stress hormones and clear your head.

After that, some social contact is welcome – meeting friends or fellow students, for example. Explaining the learning material to each other or discussing questions is an enormously effective learning trick. Those who pass on knowledge reinforce it at the same time.

I let the evening wind down quietly. About an hour before bed, I avoid screen light and prefer to read a book or listen to music instead. A fixed evening routine signals to the body that it's time to wind down. This makes sleep more restorative, and the next morning your head starts the new learning day clear and receptive again.

Curious for more? In the next edition of our series, we're covering nutrition and energy in student life – with practical tips to keep you fit and focused throughout the semester.