There are mornings with a particular kind of energy. The ones where you wake up before sunrise because you know that in a few hours the temperature will already be too high for quality training. In the mountains, everything feels different at that hour – the air is fresh, your stride is light, and your body cooperates. By nine or ten, conditions often change completely.
Years of competitive mountain running taught me that heat isn’t something to be conquered. It’s something to be understood.
This isn’t a sign of caution or weakness. It’s an understanding of physiology. When the ambient temperature rises, the body no longer operates under the same conditions. The same workout demands more energy, more adaptation, and more recovery. So in summer, the goal isn’t to “train the same as in spring” – it’s to create the conditions in which the body can perform safely and effectively.
Heat is an additional stressor on the whole organism
During physical activity, muscles produce heat. To keep its internal temperature stable, the body has to get rid of that heat. It does this mainly in two ways – by increasing blood flow to the skin and through the evaporation of sweat.
This is where the physiological challenge begins.
The heart has to supply working muscles and the skin, where cooling takes place, at the same time. As a result, heart rate rises at the same exercise intensity, and perceived effort is greater than in moderate temperatures. If the air is also humid, sweat evaporates more slowly, cooling becomes less effective, and the risk of overheating increases.
This means that a slower pace in the heat isn’t a sign of poorer fitness. It’s a normal response of the organism to changed conditions.
The body doesn’t just add up kilometers – it adds up all sources of load
When planning training, we tend to think mainly about the intensity of the workout. We less often consider that the body doesn’t distinguish between different types of stress.
Lack of sleep, psychological stress, dehydration, heat, hormonal changes, and physical exertion all represent a combined load on the organism. Each of these factors requires adaptation, and together they affect the body’s ability to maintain internal balance, or homeostasis.
If the organism is already under strain from everyday stress or insufficient recovery, heat becomes an additional burden. Fatigue sets in faster, performance drops, and recovery slows down.
That’s exactly why the best summer workout isn’t necessarily the hardest one. It’s often the one that takes the body’s current state into account.
Adapting isn’t giving up – it’s physiological intelligence
One of the biggest misconceptions is the belief that we should achieve the same results at 32°C as at 18°C.
We shouldn’t.
High temperatures increase the physiological load on the organism, which is why adjusting intensity is one of the most important protective mechanisms. The body can adapt to heat – a process called heat acclimatization – but this takes time. With regular exposure, it usually takes seven to fourteen days.
During this adaptation, sweating becomes more efficient, temperature regulation improves, heart rate at the same workload gradually decreases, and perceived effort becomes less intense.
That doesn’t mean heat stops being a risk factor. It just means the body copes with it more effectively.
A regulated nervous system means better adaptation
In recent years, there’s been growing attention to the regulation of the autonomic nervous system – not just for recovery, but for athletic performance as well.
The body performs best when it isn’t held in a state of chronic tension without reason. While fascial techniques and breathing exercises are no substitute for hydration or heat protection, they can help reduce overall physiological tension and support recovery after exercise.
When the nervous system carries less load, the body directs energy more efficiently toward the processes it needs most in the heat – cooling, blood flow, movement, and repair.
Breathing plays an important role here too. It naturally speeds up during exertion in the heat. But if, once the activity is over, we consciously slow our breath and engage the diaphragm, we encourage the shift from a state of high activation into a state of recovery. This doesn’t lower body temperature directly, but it can improve the feeling of calm and speed up recovery.
How to train more safely and effectively
A few simple adjustments can significantly reduce the physiological load on the body.
Choose the right time. Early morning or late evening are best. Between 10 a.m. and 4 p.m., air temperature and solar radiation are usually at their highest.
Adjust intensity. Instead of focusing on pace, pay attention to perceived effort, heart rate, and how you feel. If your body signals that the load is too high, trust it.
Stay hydrated. Don’t wait until you’re noticeably thirsty. Drinking regularly throughout the day and during exercise helps maintain blood volume and supports effective thermoregulation. For longer or more intense activities, replacing electrolytes – especially sodium – matters alongside water.
Choose the right clothing. Light, bright, breathable sportswear allows for better heat dissipation. A hat and adequate sun protection further reduce the load on the organism.
Prioritize cooling. If possible, pre-cool the body before exercise, choose shaded routes during activity, and allow for gradual cooling afterward. Research shows that simple measures – a cold drink or a wet towel on the neck – can reduce perceived effort during exercise in the heat.
When to stop immediately
Overheating isn’t something worth “toughing out.”
If you experience dizziness, headache, nausea, unusual fatigue, confusion, loss of balance, or muscle cramps, stop exercising immediately, find shade or a cool space, and begin cooling the body and replacing fluids.
If confusion becomes severe or consciousness is affected, this may indicate a heat-related illness that requires immediate medical attention.
Magnesium – important, but not a miracle fix
Magnesium comes up often in summer conversations, but it’s worth understanding its actual role.
Magnesium contributes to normal muscle and nervous system function, energy metabolism, and electrolyte balance. During intense physical activity and increased sweating, mineral needs can rise, so it’s important to replenish them adequately through a balanced diet or, if needed, supplementation.
Muscle cramps aren’t always caused by magnesium deficiency. They result from a combination of muscle fatigue, dehydration, electrolyte loss, and increased neuromuscular excitability. So no single supplement can, on its own, prevent all cramps or protect against the effects of heat.
In summer, I personally use Liposomal Nevrovital Magnesium+, as it’s a practical way to support magnesium intake during periods of higher physical strain. As with any supplement, I see it as support for a balanced diet – not a replacement for it.
Summer isn’t a time to prove yourself. It’s a time to cooperate with your body.
In sport, we often admire people who push their limits. But in summer, the greatest wisdom often lies in recognizing those limits – and respecting them.
Adjusting training to weather conditions doesn’t mean giving up. It means understanding how the body works and creating the conditions in which it can stay healthy, capable, and more resilient in the long run.
When we start listening to physiology instead of ego, exercise becomes more than just collecting kilometers or chasing personal records. It becomes a way of building trust in our own body.
And that, to me, is the real win – whether in the mountains, on a running trail, or wherever we move.
