Hydration in adults : role and use of electrolyte solutions

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1. The importance of hydration in adults

In adults, fluid losses may increase in certain situations, including heat exposure, intense physical activity, work in hot environments, vomiting, diarrhoea or a weakened health status. When these losses are associated with reduced fluid intake or loss of mineral salts, the risk of dehydration increases. Rehydration solutions containing electrolytes may therefore help support hydro-electrolyte balance, as part of appropriate care.

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2. What are electrolytes and what are they used for?

Electrolytes are minerals naturally present in the body, including sodium and potassium, that contribute to fluid balance, muscle function and nerve transmission. Electrolyte solutions are formulated to help compensate for water and mineral salt losses observed during heavy sweating, vomiting or diarrhoea. Some formulations also contain glucose, which supports the intestinal absorption of sodium and water.

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3. Situations of use

Solutions containing electrolytes may be considered when fluid and mineral losses are increased, particularly in the following situations:

• Intense or prolonged physical activity: particularly when sweating is significant.

• Sports and leisure activities: running, cycling, hiking, team sports, dance or other prolonged activities, especially during hot weather. In these contexts, hydration should be monitored regularly and fluid intake adapted to environmental conditions and the intensity of the effort.

• Exposure to high temperatures: particularly during heatwaves or outdoor work.

• Professional environments with high temperatures: construction sites, workshops, steel industry, glassmaking or other workplaces involving significant sweating.

• Gastrointestinal disorders: particularly in cases of diarrhoea or vomiting.

• Temporary state of vulnerability: when fluid intake is reduced or losses are increased.

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4. Interest of electrolyte solutions

The interest of these solutions lies in their ability to combine water, mineral salts and, depending on the formulation, carbohydrates in adapted proportions. They may help compensate for fluid and mineral losses, support the maintenance of hydro-electrolyte balance and promote more complete rehydration than water alone in certain situations involving significant losses.

Powdered rehydration solutions (Electrona poudre) should not be presented as energy preparations. Their primary objective is not to provide energy intended to support or improve performance, but to help compensate for water and mineral salt losses in appropriate situations.

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5. Preparation and practical use

Electrolyte solutions should be prepared and used in accordance with the manufacturer’s recommendations or the advice of a healthcare professional.

1. Boil the water if necessary, depending on local recommendations or the context of use.

2. Allow the water to cool.

3. Dissolve the contents of one sachet in the indicated volume of water, for example 1 litre.

4. Divide the solution into clean and suitable containers.

5. Consume the solution during the day, according to the recommended instructions for use.

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6. When should medical advice be sought?

Medical advice is recommended in cases of signs of moderate to severe dehydration, including intense thirst, marked fatigue, dizziness, confusion, a significant decrease in urine output, persistent vomiting or prolonged diarrhoea. Particular attention is also needed for older adults, people with chronic diseases or those taking medication that may affect fluid or electrolyte balance.

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7. Conclusion

Maintaining adequate hydration is essential for the proper functioning of the body. In adults, solutions containing electrolytes may provide useful support when fluid and mineral losses are increased. Their use should nevertheless remain adapted to the context, the person’s health status and the recommendations of the manufacturer or a healthcare professional.