Hydration is a fundamental part of nutrition. In fact, water is an essential nutrient for life because the amount produced by metabolism is not sufficient to meet daily needs.
Excellent water balance depends on maintaining a balance between the amount of water entering and leaving the body. This balance is regulated by the hypothalamic center of thirst: its task is to regulate the amount of water entering the body. Another organ that maintains the correct balance is the antidiuretic hormone ADH, which increases the reabsorption of water in the kidneys.
Dehydration reduces cardiac output, plasma volume, sweating, cutaneous blood flow and endurance.
A very athletic person is especially prone to water shortages due to excessive sweat. It is estimated that a person who plays sports needs 1 ml of water for every calorie they expend.
Water loss with insufficient compensation leads to hypohydration, that is, to a decrease in the amount of water in all parts of the body, especially in the bloodstream.
Which drink is best for hydration?
Choosing a hydration drink is a very important decision for the sports person: some experts confirm that even water alone is good if you practice it. exercise for less than 40 minutes, however if you are involved in more complex sports that last more than 40 minutes, you need an athlete-friendly drink that contains sugar or salts, because these elements can help the liquid enter the body. It is very important for the body to be able to restore basic salts – potassium, sodium, magnesium, sodium bicarbonate, chlorine and trace elements. When choosing a drink that is suitable for sports people, it is important to keep an eye on the amount of salt and sugar on the labels and choose the flavor that suits them best. Very often drinks are sold to athletes that contain infusions of vitamins, which can be very beneficial for recovery in special situations such as muscle pain.
The ideal drink should be easy to absorb and not cause gastrointestinal problems. For fast absorption, the water should be moderately chilled (about 10 °), should not be absolutely hyperosmolar and contain a minimum amount of carbohydrates from 5 to 8% and never more than 10%.
What should be the ideal water characteristics for an athlete to drink?
- the ideal fixed residue is 500 to 700 mg / l
- room temperature (if above 28 degrees and below 10 it slows down the absorption)
- smooth or slightly carbonated (if there is too much gas under stress, there is a risk of reflux)
- slightly alkaline (pH> 7) thanks to sodium bicarbonate
- is close to being isotonic
How does dehydration occur?
The main source of water loss is sweating. Not all people sweat equally, so it is important that everyone knows their characteristics and prevents dehydration in their drinking water. A balance between water inputs and outputs, that is, the balance of water balance, is an important prerequisite for the good functioning of the body. Loss of 2% -3% of body weight, consisting of water, impairs the performance of the athlete and increases the feeling of fatigue, but a more noticeable deficiency can become dangerous. Losing water means trapping fluid even in the blood.
Here is a small table of what can happen to the percentage of water lost in our body:
- 1% weight loss can cause an increase in body temperature
- 3% weight loss can lead to decreased physical performance
- 5% weight loss may cause gastrointestinal disturbances and heat exhaustion
- 7% weight loss can cause hallucinations
- 10% weight loss can cause circulatory collapse
In most healthy people, dehydration is perceived by the structure of the brain (hypothalamus), which conveys the feeling of thirst and induces the desire to drink. But if you are waiting for the stimulation of your thirst for drinking, especially during physical activity, it means that you are already dehydrated, which makes it difficult to recover from an already threatened situation in our body. This is why it would be beneficial and recommended to drink regularly during exercise without waiting for thirst stimulation.
Dr. Marco Castellazzi, surgeon, reminds us that: “The clear indication comes from urine, which in case of dehydration looks very concentrated and bright yellow, if instead your hydration is correct, the urine appears clear in abundant and clear. Another method to immediately understand if your hydration is sufficient is to lift the skin fold of your hand and see how much skin it takes to return to its aligned position, the more water is lacking, the more the skin fold will return to the place is slow.
Remember also that often in older people and in some pathologies, the feeling of thirst changes, and sometimes it is unreliable.
Good hydration is the basis for proper bowel function and adequate urine output. Remember that two-thirds of the body is water. ”
You should also have a good supply of water before engaging in any sport to ensure optimal hydration at the moment of effort. Some people, however, prefer to have plenty of water long before engaging in any sport, and this action is highly undesirable: in fact, drinking a lot of water even an hour before can stimulate diuresis, and as a result, the elimination of many fluids and strongly discouraged from drinking alcohol or caffeine.
After exercise, after it has clearly been replenished with fluid during exercise, we must take fluids to avoid chronic hypohydration, and in this way we can allow our body to restore a situation of internal balance.
How much water should you drink per day?
Approximately 9.5 liters of water can be drunk per day. Beyond this threshold, health problems can arise, in some rather serious cases, due to a marked change in the concentration of electrolytes in organic fluids (hyponatremia). An example is an athlete who died of hyponatremic encephalopathy during the Boston Marathon after drinking 15 liters of drinks during 5-6 hours of his run.