How do temperatures affect the performance of World Cup players?

Abefore implicated with the performance of the portuguese selection in World 2026, it is remembered that these games take place in full summer temperatures and in places with very different weather conditions.

If there is a slip in the field, can some players’ poor performance be justified by high temperatures? 

According to some experts, the heat in fact increases the cardiovascular load, accelerates dehydration and can reduce technical accuracy in intense efforts. In some cases, athletes are even forced to stop. However, note that this warning is not only for the players who go to the World Cup. If you're going to train during hours of higher heat, know what you need to consider.

What happens when you exercise outdoors?

“ In a hot game, the player does not tire out just by running too much, but because his body is competing simultaneously against the opponent and against temperature. Heart rate rises faster, more fluids are lost and each sprint has a greater impact on the next action. This can cause the player to be late for an appointment, reduce the maximum speed he can maintain or need more time to recover after an intense effort,” explains Alejandro Maroto, manager of Blua de Sanitas, an Iberian company owned by Bupa.

Faced with these cases of extreme heat, the body has to devote part of its resources to dissipation of heat and, to this end, “increases perspiration and diverts more blood flow to the skin and, consequently, the muscle has less margin to sustain intense efforts, forcing the heart to work with an additional load”.

In addition, these experts explain that this is also reflected in decision-making: A thermal fatigue affects mental clarity, ed coordination and technical precision. “A dehydrated or high body temperature player can make a less accurate choice in the pass, miscalculate an entry or make mistakes that would normally not occur under more usual environmental conditions,” they describe.

“Training with heat requires a change of mind. It is not about showing resistance, it is about adjust the intensity for the exercise to remain healthy. In summer, an intelligent session can consist of making less volume, rest more and end up with good sensations. Force when the body no longer regulates well the temperature increases the risk of exhaustion, injury or insolation ", clarifies the personal trainer of the Blua de Sanitas.

After all, how can you do sport (safe) even during hot days?

Stay hydrated (even before feeling thirsty)

According to these experts, a practical tip to perceive the hydration level of the body is to observe the color of the urine before exercising. If it is too dark, it is preferable to delay or reduce the intensity of the training session.

Avoid high-intensity training in hours of higher heat

If sunbathing is already problematic, imagine to exercise! Serial sessions, climbing training, HIIT or intense games should be reserved for early morning or late afternoon.

Know how to choose the most suitable equipment

Dark, tight or breathable clothing makes it difficult to dissipate heat. It is preferable to wear light clothing, a cap in case of direct sun exposure and also sunscreen for the skin. On long routes, it is indispensable to carry drink.

Abort activity at first warning signal

Dizziness, chills, nausea, severe headache, persistent cramps, confusion or loss of coordination are strong enough reasons to stop the activity immediately. In such cases, it is necessary to seek shade, refresh the body, drink liquids gradually and ask for help if the symptoms do not improve.

Reduce training session period or decrease intensity

The BBC is also aware of this method, as “sometimes a shorter walk in the morning, or some light movement inside the house, is safer and more realistic than trying to follow the same routine rigidly,” explains García Witulski, an environmental lifestyle epidemiologist at the Catholic University of Argentina.

Alongside this, the specialist adds that warmer conditions generate more “thermal tension”, which leads to increased fatigue and discomfort.