In recent years, we are seeing that more and more athletes are practicing triathlon, ironman, trail, marathon, etc. and some are suffering the consequences of not being sufficiently hydrated. A lot of mineral salts are lost through sweat in addition to water. This affects the performance of the athletes.
If we are almost 70% water, it is logical to think that what happens in our organism has a direct relationship with the liquid element. This body water contains electrolytes and solutes in solution. It forms the extracellular fluid, the main extracellular ion being sodium and potassium as the main, more concentrated, ion of the intracellular fluid.
Water is an acidic nutrient but it is fundamental for our body to remain properly structured and in perfect working order. If water is essential for the organism, the maintenance of the water balance is fundamental for the human being. Any imbalance can negatively affect physical performance and harm the body’s health (Veicsteinas and Belleri,1993).
A person can lose around 2.5 litres of water a day: 1.5 litres through urine, 100 ml with the faeces and 1 litre through evaporation, breathing and perspiration (which increases considerably in very hot environments and above all with physical exercise).
When we talk about sportsmen and women, these water losses increase and consequently the water requirement increases. In extreme conditions, water requirements can increase by 5 or 6 times the normal amount (Iturriza et al., 1995).
Dehydration is defined as the dynamic loss of body water due to sweat during physical exercise without fluid replacement, or a replacement that does not compensate for the proportion of fluid lost.
When we lose water, we carry away mineral salts. The ions removed depend on the route of exit. Sweat: Na+(sodium) is lost, about 40mEq/l; Potassium K+, about 3mEq/l); Chlorine, Cl- about 40 mEq/l; in diarrhoea, on average they are Na+100 mEq/l; K+30-40 mEq/l; Cl-40 mEq/l and CO3H-(bicarbonate) 22mEq/l