60% of our body is water, so it is not surprising that we need to ensure optimal hydration levels to maintain good health and performance. Sometimes it can get a bit difficult to sustain hydration at optimal levels, especially on sunny and hot days of summer, when our sweating rate normally is going to be higher, and so our risk of dehydration also increases. 

If you are not sure what you have to drink for your trainings, how much and how often, have a look at this post to discover the most important aspects that you need to consider to ensure a good status of hydration and prevent its opposite side, dehydration.


Dehydration and its outcomes

Sweating is a very individual body function, with most people losing about 500-1000 ml of fluid (through sweating) per hour of exercise, depending on the specific environmental conditions (1). Although the production of sweat is a beneficial response, to lose heat from our body and maintain a regulated temperature, if such fluid losses are not replaced at an adequate rate, dehydration and performance can be affected in several ways (2):

  • Reduction of blood volume
  • Decreased blood flow of the skin
  • Decrease in the sweating rate
  • Decreased heat dissipation
  • Increase in core temperature
  • Increased rate of muscle glycogen use
  • Impaired digestive function

Sweat loss can be reflected in a decreased body weight, and it is known that the greater the body weight loss, the greater the negative consequences. In fact, it is known that a loss greater than 2% of body weight, has negative consequences on performance, and as that percentage increases, it can reach the risk of death. Therefore, hydration status is an aspect that must be controlled to ensure optimum performance and to prevent any risk related to sweat loss.


How to control your hydration levels

Urine color and volume is one of the most accurate factors to control your hydration levels. Dark colored urine may indicate that you are dehydrated and need to drink more (1). Bare in mind that some foods and vitamins can change the color of urine, even when hydrated.

Well hydrated



Very dehydrated

Severely dehydrated

To ensure a good hydration status (whether you are training or not) you should drink 2-3L of water per day. Other fluids such as fruit and vegetable juices and sports drinks can be also included, although these would be more recommended for before-during-after training and competition.


The importance of electrolytes

The composition of sweat contains mainly water (from the aqueous component of blood known as plasma) and important substances known as electrolytes. Electrolytes are minerals that have a crucial role in cell function in particular for the transport of substances inside and outside them.

Sodium is the most important electrolyte, as it helps to stimulate thirst, improves palatability and promotes the absorption and retention of liquids (3). The concentration of sodium in our bloodstream is normally around 135-145 mmol / L. When blood sodium levels fall below this range, this is known as hyponatremia (2). Sodium loss, like sweat loss, is very individual, and some athletes lose more sodium than others.

Therefore, rehydrating the body only with water can dilute plasma sodium levels to lower concentrations, which leads to a greater extent the negative effects of dehydration. So, it is recommended that hydration solutions containing electrolytes (especially sodium) have higher levels than common water to ensure adequate hydration before, during and after resistance exercise.


Products to consider for an optimal hydration:

Carbohydrate free drink, an ideal choice to ensure hydration without any energy supply.

A combination of electrolytes and minerals to ensure an optimal hydration status, contribute to muscle contraction and protect bone health.

An upgraded formulation from SALTS product to ensure optimal performance at high intensities and long duration exercises. With added ginger to prevent GI problems.

With added caffeine, this product is indicated for hot and humid environments, in order to prevent muscle cramps and impairment of performance.

Apart from these products containing the electrolytes that we have mentioned before, do not forget to include water to replenish your body fluids. To ensure you are drinking enough at all times, remember to take sips every 15-20 minutes. Secret tip: if you are taking a drink that contains some type of carbohydrates, you can do a mouth rinse of 5-7 seconds before drinking it, to increase the benefits of these carbohydrates from the beginning.

As you can see, hydration is a very important aspect for your performance, so make sure you always maintain these levels topped up. Remember to drink 2-3L of fluid per day (especially water), control your urine color, choose an electrolyte containing product that suits your training and/or event, add the fluid (water and/or sports drink) and take small sips with rinses continuously.


Ainhoa Prieto Martinez
Sports nutritionist


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