The market is flooded with isotonic and energy drinks, i.e. functional drinks. They are expensive and have a hard candy flavor, but drinking them is in a good tone. Does drinking sports drinks from the store really make sense?
We lose water constantly, not only with urine and sweating, but also by breathing (400 ml). In hot weather, with high air humidity, and during intense exercise, we excrete more of it through the skin. But sweat is not just water. It is s alty because it contains mineral s alts in an electrolyte form (potassium, sodium, chloride, calcium, magnesium ions). They take part in many important physiological processes, including in conduction of nerve signals and muscle contractions, including the heart muscle. Excessive loss of water and electrolytes can be dangerous - it manifests itself in a sharp decrease in physical efficiency and increasing weariness; can lead to fainting and unconsciousness.
Isotonic drinks designed for athletes
In order to replenish the ingredients lost with sweat, we need water with the optimal content of mineral s alts. Optimal, i.e. with the concentration of ingredients that body fluids have. Contrary to appearances, it should not be highly mineralized water! Trainers warn against drinking highly mineralized water during training or competition. You can drink it only after them. Otherwise it will squelch your stomach or cause colic. This is because the high concentration of minerals prevents the absorption of water. It is with the special needs of athletes in mind thatisotonic drinkshave been created. Their name comes from the wordisotonymeaningpressure equalization .
Mysterious phenomenon of osmosis
Fluids and all foods are absorbed primarily in the small intestine and partly in the large intestine. The intestine is a long tube lined with a membrane that is covered with protrusions (villi) that increase its surface area. Thanks to this, blood vessels that tightly wrap the intestine can capture its contents faster. This is done by the principle of permeation, or osmosis (movement of fluids through a semi-permeable cell membrane).
As a result of the osmotic pressure generated, electrolytes (and all dissolved nutrients) travel from the intestine to the blood and fromit reaches all cells of the body. If the concentration of the drink ingredients is equal to the blood concentration, then the osmotic pressure is even (isotonic) and absorption is smooth, easy and even. It happens even faster when the osmotic pressure of the swallowed liquid is lower than the osmotic pressure of the blood - the penetration takes place immediately, based on the principle of suction. It is worse when the situation is the opposite and the amount of ingredients dissolved in the drink exceeds the blood concentration. Then the drink is absorbed slowly.
Important1 percent of water lost during exercise, when we sweat more, entails a loss of 10%. exercise capacity. During intensive training, a person can lose 1-1.5 liters of water within an hour, i.e. approx. 2%. body weight. This reduces the body's efficiency by up to 20 percent. After losing 4 percent of water, there is a complete loss of strength.
Three Levels of Fluid Absorption
Liquids are absorbed differently, depending on the concentration of their ingredients.
- The fastest - weakly and moderately mineralized waters, herbal teas brewed from them, diluted fruit and vegetable juices. This is called hypotonic or hypoosmotic fluids (sometimes such terms are found on the labels of "functional fluids") with the lowest concentration of ingredients.
- Slow - thick fruit and vegetable juices, and beverages that are heavily sweetened, flavored, or colored, including energy drinks. This is called hypertonic fluids, or hyperosmotic fluids - characterized by a higher concentration of minerals than what we have in the body. Because of this, osmosis is slower. So drinking energizers and sweet juices is not a good way to hydrate the body quickly. Normally it does not matter, but in people actively practicing sports, this slowing down of fluid absorption may be dangerous.
- Optimally - special isotonic (iso-osmotic) fluids, the composition of which is balanced and the concentration identical to that of body fluids. Drinking such a drink does not disturb the body's water and electrolyte balance, it facilitates even hydration. By drinking isotonic drinks, we improve the absorption of water along with the necessary ingredients. It is most desirable during profuse sweating, i.e. loss of electrolytes.
When to drink sports drinks
They are especially recommended during prolonged physical exertion. They allow you to easily rehydrate the body. They contain the right combination of minerals (which regulate the water and electrolyte balance as well as the work of muscles) and carbohydrates. They effectively replenish those lost with sweatelectrolytes, deficiencies of which can lead to muscle cramps. They ensure that a constant blood glucose level is maintained and the energy lost during exercise is constantly replenished, which delays the onset of fatigue symptoms. Producers often add vitamins to them, e.g. from group B, which are involved in energy release processes. Isotonic drinks are definitely worth drinking in the fever, in the tropics, in high humidity, in any situation when we sweat profusely and we risk dehydration.
Action of sports drinks:
- they effectively quench your thirst,
- hydrate - prevent dehydration,
- complement the deficit of electrolytes,
- give a sense of freshness,
- give you an immediate surge of energy, strength and endurance,
- prevent the exhaustion of the body.
Difference between sports drinks and energizing drinks
Energy drinks are fundamentally different from isotonic drinks. In the moment of fatigue - physical and mental, they are to help quickly mobilize the body to even greater effort. These are typical "boosters". They stimulate the central nervous system, improve energy metabolism in tissues, which briefly stimulates the body to work more intensively. They fight the symptoms of fatigue and improve concentration. They can save, for example, a tourist in the mountains or on a bicycle trip from exhaustion.
They are sometimes referred to as "disco-drinks" because they allow students to go to class in the morning after having fun all night. It is fashionable to serve them with alcohol, which - attention - in such company is more striking. As a rule, they are hypertonic, that is, with a high concentration of ingredients. And high osmotic pressure delays their absorption.
They are definitely not suitable for thirst quenching. In case of great effort, it is even recommended to dilute them with water, because the caffeine contained in them dehydrates, and for example, a marathon runner in the last kilometers needs both an energy "kick" and hydration. They are often sold as a concentrate from which to prepare a drink. Do not exceed its maximum dose during the day.
Ingredients for energy drinks
This is "condensed fuel". They contain caffeine or guarana extract containing it. It stimulates the secretion of adrenaline (the fighting hormone) and norepinephrine. They also contain taurine and L-carnitine (amino acids that facilitate the use of energy) and easily absorbable simple carbohydrates with high caloric value (glucose, fructose or sucrose). They also contain minerals and synthetic vitamins, but also harmful preservatives (e.g. potassium sorbate and sodium benzoate), artificial colors and flavors, flavor emulsions.aromatics, sweeteners, carbon dioxide.
Effect of energy drinks
- remove fatigue,
- ensure full mobilization.
Be careful with energy drinks
Manufacturers do not mention it, but energy drinks should not be reached without thinking and too often. Let us really use them in exceptional situations. The mental arousal they cause is due to the vasodilating caffeine. Maybe it's better to drink coffee or green tea? Cistus infusion also has energizing properties. Natural drink, tastier and cheaper. Sometimes the label says: "energy drink", but the composition shows that its main task is to keep the body hydrated. This also adds energy, but does not allow the product to be classified in the same group as caffeinated drinks.
The mechanism of desire
When you sweat profusely, your body fluids condense and your blood osmotic pressure rises. The body turns on vasopressin, the hormone that tells the kidneys to "stop, save water." Then we feel thirsty and need to refill fluids, because the body poisons itself with harmful metabolic products (the kidneys do not function, and this is our washing machine, which cannot work without water).
Drinking strategy during training
It is better to prevent desire than to satisfy it once we feel it. Always drink before you feel thirsty, because it already means dehydration. This protects against a decrease in the level of electrolytes in the blood, and thus against a decrease in our efficiency. Losing a kilogram of body weight through exercise means sweating a liter of fluids. They need to be proportionally and systematically supplemented - by drinking during training.
However, you must not absorb too much fluid at once, because it will not be absorbed by the gastrointestinal tract (it will be excreted immediately). The amount depends on the individual needs (everyone sweats differently), the intensity and duration of training as well as the temperature and humidity of the environment. When sweating very intensively, we should consume about 0.5 l of drinks per hour. Let's drink often, in small sips - at most a glass at a time, let's keep the liquid in our mouth (it is also absorbed here).
Read also: Pre-workout supplements - what are the ingredients, how do they work, are they he althy?
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