The importance of sodium for athletes

 

by Elena Casiraghi

Sweating, and the subsequent evaporation of sweat, is essential for humans, especially athletes. This process helps reduce excess heat produced by the body during exercise. It is a natural thermoregulation mechanism that absorbs a significant amount of heat (2430 kJ/l), thereby cooling our body.

The consequences of sweating

Sweating leads to the loss of several minerals, primarily sodium, chloride, potassium, and magnesium. The more intense the effort, the higher the ambient temperature, humidity, and solar radiation, the more abundant the sweating and, consequently, the loss of these minerals. It is crucial to replenish these losses to avoid various problems.

Sodium: how much is lost through sweat?

Sodium is the most prevalent mineral lost in sweat. Potassium is 6-8 times less concentrated in sweat than sodium, and magnesium is 100 times less. Evidence of sodium in sweat can be seen in white stains on clothing, especially around the neck and underarms. More prominent stains indicate less adaptation of the athlete to the ambient temperature during training or competition. 

What happens in case of sodium deficiency

Sodium deficiency can have serious consequences. In extreme cases, it can cause hyponatremia, a condition where blood sodium levels are significantly low. This can be due to heavy sweating, excessive intake of mineral-poor water, or a combination of both, and can occur during or up to 24 hours after exercise. Hyponatremia is the most dangerous consequence to manage, but not the only one. Sodium deficiency also reduces the intestine's ability to absorb water, increasing intestinal stress during exercise and reducing hydration levels. Sodium is primarily absorbed in the ileum, the final section of the small intestine. 

Maintaining sodium levels during training and competition

Post-exercise, the body's instinctual craving for sodium-rich foods, or simply adding table salt to meals, helps restore sodium levels. 

However, maintaining sodium levels during physical exertion is less straightforward. While table salt (sodium chloride) was once a basic solution, nutritional science has developed targeted solutions to replenish sodium during exercise.

Athletes now have access to various products to prevent sodium deficiency, including powder mixes, effervescent electrolyte tablets, and sodium capsules. Innovative sodium-enriched energy gels, developed through collaboration with athletes from Lidl Trek and UAE Team Emirates, are particularly useful as carbohydrates enhance sodium absorption in the intestines. 

Sodium and muscle cramps Sodium is often linked to muscle cramps. While its effects on muscle contraction are clear, its connection to exercise-induced cramps is not. Cramp causes may vary, and although they occur more frequently in hot conditions, prolonged exercise, and dehydration, it is not proven that sodium loss is the primary factor. Heat, fatigue, and dehydration might all contribute, particularly at the nervous system level.

Two tips for improving performance

The variety of electrolytes supplements allows athletes to use training to identify the most suitable solution for their needs and the environmental conditions of their competitions. The best solution will promote optimal gastric emptying and intestinal absorption. Key considerations include:

• Timing: drink regularly during exercise. Generally, take small sips every 15 minutes. In case of heavy sweating, increase frequency to every 10 minutes. Do not wait to feel thirsty; preempt it. The stomach absorbs about 180-210 ml of fluids every 15 minutes, sometimes less (125-150 ml). Thus, in an hour, one can effectively consume 720-840 ml of fluids. Consuming more, may slow gastric emptying and provide no additional benefit.
• Acclimatization: an acclimated athlete loses about 1 g of sodium per liter of sweat, compared to nearly 1.5 g/l in a non-acclimated athlete. This discrepancy occurs because non-acclimated sweat is more concentrated in minerals. Acclimatization, which takes 7 to 14 days, increases blood volume, reduces heart rate, and enhances sweating efficiency, improving performance in hot and humid conditions.

Summary: Sodium is the most concentrated mineral lost in sweat Sodium deficiency from increased sweating can impact performance and well-being Proper supplementation alone isn't enough; timing is crucial Acclimatization is a winning strategy.

 

 

Bibliography

- Jeukendrup, A.E. - Carbohydrates and exercise performance: the role of multiple transportable carbohydrates. Curr Opin Clin Nutr Metab Care. 2010 Jul;13(4):452-7.

- Sawka, NM, Montain, SJ. - Fluid and electrolyte supplementation for exercise heat stress. Am J Clin Nutr August 2000 vol. 72 no. 2 564s-572s.

- Noakes, T. - Lore of running. Ed. Human Kinetics, 2003.

 

NOTE: The information provided is for informational purposes only and is not intended to replace the advice of your physician or healthcare professional. The information is intended for healthy individuals, and any dietary regimen or physical activity should be supervised by a competent professional according to Italian law. Enervit SpA assumes no responsibility, as the information is for informational purposes, and anyone interested in undertaking any dietary or physical activity program should consult their specialist.