Why salt is important for athletes

During exercise, body water is lost through sweat. Especially when it's warm outside or when you are exercising for a prolonged period of time. But did you know that sweating does not only lead to the loss body water, but also to the loss of salt? We all know replenishing lost fluids is important, but is replenishing salt just as important? What happens if you don’t? When do you need salt and how do you ensure sufficient intake? In this article, we will tell you everything about the importance of salt when exercising.

During exercise, sweat losses are often greater than the intake of water. This results not only in the loss of body water, but also in the loss of important electrolytes. One of those electrolytes is salt, which is composed of two ions: sodium and chloride. Sodium in particular is an important ion for our body, of which the primary source is the consumption of salt. Sodium is largely responsible for various body functions, such as:

  • The functioning of body cells
  • The regulation of pH (acidity) levels
  • The regulation of body fluids, blood volume and blood pressure, affecting the function of the whole cardiovascular system.

However, we often consume way too much salt and thus sodium (generally more than double the recommended amount!). Too much sodium intake is associated with increased blood pressure, which is a risk factor for cardiovascular disease. The recommended daily intake of sodium is 1.5g/day, which corresponds to 3.75 grams of salt. But does the same apply for athletes, who may have greater rates of sweat loss and consequently lose more salt? Should athletes replace salt losses? 

Salt & sport

During prolonged exercise (2 hours or more) or exercising in the heat, the risk of salt loss is higher. This is mainly a direct result of sweating (have you ever tasted your own sweat?). How much salt an athlete loses, depends on the degree of sweating and the concentration of salt in it. This however, depends on various factors such as genetics, how well-trained an athlete is, the nutritional intake and the ability to acclimatise to the heat. But did you know that a loss of fluids and salt (especially sodium) could affect sports performance?

Several studies have shown that a large loss of fluids and salt negatively affect sports performance. How and why this occurs? Partly because the plasma volume in the body decreases. This sounds pretty complicated, but it actually means that the blood becomes thicker because it contains less liquid. Because of the thickened blood, the heart has to make a bigger effort to pump enough blood through the body. As a consequence, the heart rate goes up. In addition, a loss of fluids and salt also may affect body temperature. Temperature will be higher when you have a lack of body water and you can suffer from cramps. You can imagine that your body is getting a hard time. 

Research shows that an effort of 2 hours could lead to the loss of 2 to 3% body weight of fluids and up to 1.6g till 5g of salt (although this differs per person). In order to keep the functioning of the body as optimal as possible and to prevent a decrease in sport performance, it is important to prevent excessive loss of fluids and salts. However, this could be difficult. Thirst often does not correspond with the amount of body water that is lost. In general, you only get thirsty when you already have lost 2% of your body weight in sweat. The result is that there is always some dehydration during exercise. Thereby, drinking solely water will not supply you with needed salts. 

What to do?

A sports nutrition product containing salts can provide a solution. The intake of salt during exercise has several advantages:

  • It stimulates the feeling of thirst, which probably makes you drink more (less chance of dehydration).
  • It ensures a better absorption of water and carbohydrates, which contributes to sufficient energy and the prevention of muscle fatigue.
  • It retains the ingested fluids in the body.

This all contributes to proper functioning of the body and the preservation of an optimal sport performance. Therefore, it is recommended to consume sports nutrition containing salts during and after prolonged exercise and / or in warm conditions. Research indicates that 450mg of sodium intake per hour of exercise is necessary to keep the body functions - and therefore sport performances - as good as possible.

Vifit Sport energy range

In the autumn of 2018 Vifit Sport will come with a new Energy Range! Per serving (bar or gel), a total of 100mg sodium is added. This means that by consuming 3 servings of Vifit Sport during and/or after your workout you will not exceed the maximum recommended amount of sodium per day, although it will help you to replenish the salts lost by sweating.

Date: 25/10/2018
Author: Monique van de Velde, on behalf of Vifit Sport

- EFSA. Tolerable Upper Intake Levels for Vitamins and Minerals. Scientific Committee on Food Scientific Panel on Dietetic Products, Nutrition and Allergies. 2006. 480 p.
- Murray, B. (2007). The role of salt and glucose replacement drinks in the marathon. Sports Medicine37(4-5), 358-360.
- Sawka, M. N., & Montain, S. J. (2000). Fluid and electrolyte supplementation for exercise heat stress–. The American journal of clinical nutrition72(2), 564S-572S.
- Stachenfeld, N. S. (2014). Sodium ingestion, thirst and drinking during endurance exercise. Sports Science Exchange27(122), 1-5.
- Vrijens, D. M. J., & Rehrer, N. J. (1999). Sodium-free fluid ingestion decreases plasma sodium during exercise in the heat. Journal of Applied Physiology86(6), 1847-1851

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