Proper hydration of the body under stress conditions.
Adolescents practicing sports should pay particular attention to fluid intake. Their consumption should ensure a constant level of hydration (hydration) the body, covers losses mainly in the form of sweat and urine. No diet will be wholesome, if it does not compensate for the fluid lost by the body. There is a lot of evidence, that the loss of body fluids with sweat greatly reduces the exercise capacity and that even a small degree of dehydration reduces the physical efficiency of the body. The dehydration of the system leads to a reduction in the plasma volume, increase in blood viscosity and reduce the ability to transport oxygen and other nutrients to the tissues. The consequence of consuming inadequate amounts of fluids are also disturbances in thermoregulation processes, what especially with long efforts, in conditions of high ambient temperature, it may overheat the body.
Young athletes are usually guided by thirst when replenishing their fluids, which unfortunately is not a good indicator of this, when you need to start drinking, and how much the player should drink, to compensate for the body fluids lost during exercise.
It is only then that the feeling of thirst arises, when the loss of body fluid is approx 1,0% body weight. For the weighing contestant 70 kg, this means that thirst only appears with a water loss of approx 700 Ml. Athletes should keep this in mind, and start fluid replenishment earlier, before you feel thirsty. This protects the body against the onset of a state of deeper dehydration, simultaneously conditioning its proper functioning under stress conditions. During exercise, the body loses not only water but also minerals with sweat, mainly sodium, chlorine, potassium and magnesium. So it is important, not to drink only clean water when replenishing fluids, because it is unable to compensate for the lost mineral compounds. Fruit or fruit and vegetable juices are more recommended for this purpose, although the most recommended in this case are the so-called. isotonic solutions. Drinks of this type hydrate very effectively because the molecular concentration of all ingredients contained in them is so selected, that they are absorbed very quickly, including water. Composition of isotonic drinks, in terms of the minerals they contain, it is similar to the composition of sweat, hence complement it, what the body loses in sweating. In addition, isotonic drinks provide a certain amount of carbohydrates, which protect the body during exercise against lowering blood glucose levels, which in turn prevents fatigue. An example of isotonic drinks available on our market are, among others: Isostar, Gaterade, Mineral Light or Izomax.
Please note, that natural fruit juices are too concentrated solutions (hypertonic), therefore, in order to hydrate them faster, they should be consumed after diluting them with water, relative 1 a portion of juice on 2 portions of water.
Drinks during exercise should be taken frequently, what 15-20 minutes, in small portions (approx.125 ml), using breaks in training.
Drinking fluids is extremely important not only during exercise, but also after its completion. In order to replenish the carbohydrate reserves consumed during training, drinks enriched with this nutrient should be administered as soon as possible after the end of training. maltodextrins dissolved in fruit juice or isotonic drink. However, one must remember, that these types of drinks, provide more carbohydrates (hypertonic solutions), but they hydrate much slower than isotonic solutions, hence they are recommended after physical exertion, not during it. After consuming portions of more concentrated carbohydrates right after the end of training, players should return to consuming less concentrated drinks. The lack of fluid in the body must be compensated for at the latest 24 hours after exercise. The young athlete should start training or competition the next day when fully hydrated.
Please note, that, like the feeling of thirst, it appears only in a state of a certain dehydration of the body, thus, quenched thirst does not mean full rehydration. Research shows, that the amount of fluid taken until thirst is quenched is often insufficient. Competitors should obey the rule, to drink more, 1,5-2,0 glasses over or around quenched thirst 150% fluid lost during exercise. Weighing players before and just after training, taking into account the amount of fluids drunk during training, allows to determine the amount of water lost with sweat.
In the case of young athletes, it is highly advisable for a trainer to supervise the administration of fluids, to get them into the habit of drinking while exercising. It is also highly recommended to systematically control the body weight of each athlete before and after training, which may indicate in which competitor is chronically dehydrated.