What should an isotonic drink have?

By Paula Marcé,

The hottest months of the year are approaching and the importance of good hydration when practising sports is even more important. For this reason, today we talk about what happens when athletes do not hydrate properly, we analyze the drinks we have to take depending on the physical activity and we suggest a recipe for a homemade isotonic drink.

Why is good hydration important?

Water is an indispensable element for life. It is the means by which body fluids dissolve, transports nutrients in the cells, maintains body temperature through evaporation-sweating, among other key functions. We also have to take into account that 45-70% of body weight is water, a percentage that can vary depending on age and sex due to changes in body composition.

“Good hydration is essential

to improve physical performance

and avoid injuriesvitar lesiones”

For the good functioning of the organism, the amount of water must be kept constant and stable. Therefore, there must be a balance between its intake and elimination. At rest, the body’s water needs are established at 33 ml/kg/day.

We can obtain water from different sources, the main one is the intake of liquid and the production of water during cellular metabolism. In relation to water losses, the main one is in the form of urine, followed by losses due to cutaneous transmission, pulmonary ventilation, sweating, and excrement.

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What impact does hydration have in sports?

The balance between the intake and the elimination of water is especially relevant in the world of sports to maintain a good thermoregulation and temperature stability of the body, ensuring a good functioning of the cardio-circulatory system during exercise.

“You do not have to wait until you

are thirsty, as it does not appear

until you have lost 1-2% of body water”

Moreover, good hydration is essential to improve physical performance and avoid injuries, since many of them are produced by chronic dehydration. A loss of 4-6% of water decreases up to 20-30% of the performance of an athlete. In addition, percentages of higher water losses can cause a heat stroke and have a serious effect on health.

Therefore, you do not have to wait until you are thirsty, as it does not appear until you have lost 1-2% of body water, that is when the performance has already begun to decrease. You have to drink small amounts, but often.

When we practice sports, the water needs increase due to the dehydration produced by sweating, to eliminate the heat generated by the muscular work. If the heat is not removed, the temperature increases 1ºC every 3-5 minutes, with the consequent muscular claudication. It is recommended to ingest volumes of 100-250 ml every 15-30 minutes, at 14-21ºC during sports activity.

“The main symptoms are irritability,

weakness, dizziness, chills,

nausea and/or vomiting”

For this reason, it is important that the athlete is aware of the factors that may favor the loss of body water and dehydration. Mainly: temperature, humidity, type of physical activity, duration, intensity and individual characteristics (sex, age, body surface, etc.).

How can we know if we are dehydrated?

The main symptoms are irritability, weakness, dizziness, chills, nausea and/or vomiting, muscle cramps, disorientation, decreased performance and increased risk of heat stroke.

The color of the urine is a good indicator and we can also use the technique of double weight. That is, weigh yourself before and after doing physical activity. The difference in weight gives information on the amount of fluid lost and, therefore, the percentage of weight loss can be known. During the hours after training, you will have to intake 1.5 times more of the lost weight.

What does a good replacement drink need to have?

In the market, there is a wide variety of sports drinks, but usually, its composition is not adequate. Therefore, it is important to know what a replacement drink has to have in order to choose it properly.

In general, a replacement drink must contain water, carbohydrates (glucose, sucrose, maltodextrin, and fructose) and electrolytes (sodium, chlorine, potassium, magnesium, and calcium) to improve performance.

“In intense and/or long-term

exercises and in hot environments,

isotonic drinks are recommended”

Water prevents dehydration and the concentration of carbohydrates (between 6-8% with a 2:1 ratio glucose/fructose) avoid saturating the transporters, maintains fluid balance, provides energy, reduces the degradation of reserves of glycogen, maintains stable blood glucose levels, and accelerates the assimilation of water.

If the drink has <5% sugars, it would have a low energy value, but if it exceeds 10% it would delay gastric emptying and water absorption, causing diarrhea and gastrointestinal discomfort. The contribution of electrolytes, mainly sodium, helps the retention of water and the absorption of glucose.

Hidratarse es mucho más que beber agua. Dale a tu cuerpo lo que necesita. . #isostarspain #isostar #sports #outdoor #deporte #isotonic #isostarspain #sportsnutrition #cycling #trail #running

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What replacement drink should I take?

In intense and/or long-term exercises and in hot environments, isotonic drinks are recommended because they facilitate the absorption of water and minerals. These drinks have between 6-9% of carbohydrate and the same concentration of sodium (460-1150m/L) and potassium as the extracellular liquid (plasma). Therefore, it does not affect the content of cellular water.

“in long-term exercises, but the low

intensity and/or low temperatures,

hypertonic drinks are recommended“

In exercises of moderate intensity that do not need an extra supply of nutrients, combined with a balanced diet, hypotonic drinks are recommended. These have <4% content of carbohydrates and a low concentration of sodium compared to plasma. Therefore, they cause an increase in extracellular water that, if maintained, the body responds by increasing diuresis inducing dehydration.

Finally, in long-term exercises, but the low intensity and/or low temperatures, hypertonic drinks are recommended since the loss of water is not high and the athlete needs nutrients. These drinks have a 10% carbohydrate and a high concentration of sodium in relation to the extracellular fluid, which causes cellular dehydration.

Can I prepare my own drink at home?

Even though you have replacement beverages on the market, you can also prepare your homemade isotonic drink to your liking. Here I enclose a recipe for an isotonic drink at 6% carbohydrates approximately:

Ingredients:

250 cc of natural lemon juice

20 g of fructose

20 g of sucrose

1 tablespoon of Sodium Chloride (salt)

750 cc of water