Heat Acclimation and Cooling Strategies for Athletes

High temperature and humidity are adverse conditions that directly and indirectly affect physical performance ^1,2. In addition, exercising in conditions of high temperature and humidity increases the risk of gastrointestinal alterations during exercise ³, dehydration ^4,5, hyponatremia ^4,5, and the negative health consequences of these alterations.
Due to the competitive calendars of different sports disciplines, it is common for the most important competitive events to be held in the summer season. In fact, the season of the year is one of the determining factors of sodium loss through sweat⁶. In addition, it is common for certain events to take place in conditions of high relative humidity, such as in cities near the sea. These situations will affect sports performance, especially in athletes whose training is carried out in places with lower temperature and humidity. Therefore, there are various acclimatization or cooling strategies that could be very useful to prevent dehydration and maintain physical performance.

Acclimatization strategies

Carrying out an acclimatization phase to the weather conditions of the place where you are going to compete would be a fundamental aspect to optimize the athlete's performance. The best-known acclimatization strategy would consist of training for weeks and months beforehand in environmental conditions similar to those expected in competition ⁵. However, this is not always feasible.
Other alternatives could include training at moderate or constant loads in controlled humidity and temperature situations (for example, hot air), trying to expose the body to an environment that increases body temperature⁵.
In addition, various athletes carry out their training in indoor environments (for example, sports centers). Therefore, in the event that competitive events are held outdoors with direct exposure to the sun, the inclusion of training sessions with direct exposure to the sun could be another very useful strategy⁵.
Finally, exposure to heat through hot baths, saunas or Turkish baths (high humidity) would be another strategy used for acclimatization 5. This exposure to heat could be done passively in situations where there is no exercise component (for example, rest days), or it could be done immediately after exercise sessions in cool environments⁵.

External and internal cooling strategies

However, it is important to note that heat adaptation strategies must be closely monitored to avoid potential negative health consequences. Faced with this, different cooling strategies emerge, both external and internal, that could improve performance in hot situations 7,8. These strategies aim to compensate for the increases in body temperature produced by exercise and improve thermal perception⁵.

External cooling techniques include cooling garments (e.g., iced towels, iced vests, cooling vests), immersion in cold water, fan use (e.g., during warm-ups), or using creams, gels, or sprays with substances that allow peripheral cooling (e.g., menthol) 5. These strategies are mainly used before physical exercise and may improve thermal comfort and heat dissipation through the skin.⁵

Internal cooling techniques decrease temperature and dissipate heat through the ingestion of cold fluids or ice 5. Thus, drinking water at cold temperatures or ice slurries could have a direct effect by lowering the core temperature and improving fluid balance, preventing both hyperthermia (high body temperature) and dehydration⁵.

Finally, in situations of high temperatures and humidity it is even more important to pay attention to hydration strategies and electrolyte intakes before, during and after exercise. Therefore, in the event that isotonic or hypertonic drinks are included, ingesting them at low temperatures or in the form of slushies could be a simple, useful and effective strategy in these adverse weather situations. In this way, in addition to planning the timing of these intakes, temperature control, for example, by carrying refrigerators or containers that allow you to keep drinks cold would be an additional practical recommendation

Conclusions

Performance declines in hot and/or humid environments. Although including acclimatization strategies can be useful in this situation, they are not always feasible. Therefore, including internal cooling strategies (e.g., cold drinks or slushies) could be a useful and simple alternative to mitigate the possible negative effects of adverse weather conditions.

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References

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