Why do athletes need isotonic drinks and can they be replaced

Athletes consume isotonic drinks in order to restore the body during intensive training. In some cases it helps, in others it doesn’t. In the article, Suren Arutiunian, a sports physiologist and triathlon coach, tells whether isotonic drinks really help with prolonged physical exertion.

What is an isotonic drink

Isotonic drink is a sports drink that contains minerals, vitamins and carbohydrates. During high physical exertion, athletes sweat a lot and lose some of their nutrients along with sweat. Therefore, to maintain the right level of fluid and electrolytes in the body, they consume isotonic drinks and salt tablets.

In addition to electrolytes, they contain fast carbohydrates — maltodextrin or glucose, vitamins B, C and E. Such a complex really increases endurance and energy levels. But there are drinks that contain only salt. This means that the value of such an isotonic drinks is much lower.

The role of salts in the body

Electrolytes are mineral compounds (salts) that conduct an electric current in the body. It is necessary for the transmission of impulses in the nervous system. For example, before you raise your arm, the brain sends a signal to the biceps and after that there is movement. Electrolytes are also involved in the process of cell respiration, in the work of the heart and respiratory system. If a person does not have enough salts or, conversely, he receives them in excess, there is a negative impact on all internal processes.

For athletes, electrolytes are the main conductor of energy. They help the muscles contract, regulate the pH of the blood and save the body from dehydration. Electrolytes include sodium, potassium, magnesium and chlorine.

The norm of sodium is 136-145 mmol / liter of blood. Below 135 — hyponatremia (low sodium level in the blood), above 145 — hypernatremia (increased sodium content in the blood).  

Among all salts, sodium plays a key role. If the body has enough of it, the athlete tolerates the load more easily. If there is not enough sodium, unpleasant conditions develop: nausea, muscle spasms and dizziness. They usually occur when the sodium level drops to 120 mmol/ liter of blood and below.

Is it worth to consume isotonic drinks
 On the one hand, isotonic drinks and salt tablets help to make up for the loss of valuable substances. After all, they contain salt and vitamins. But ordinary drinking water dilutes the blood even more and lowers the sodium level. But it’s not that simple.

Firstly, the salt content in isotonic drink is significantly less than in our blood. The basis of this drink is water. Therefore, you will also dilute the blood even with abundant use of isotonic drinks. Secondly, if the drink is too salty, it causes an increased feeling of thirst. This means that during the race the athlete will consume too much water and dilute the blood again.

According to research, the amount of salt you consume at a distance does not affect the level of sodium in your blood at the finish. The reason for hypernatremia is different: excessive water consumption and also isotonic drinks.

In addition, there are no guarantees that the additional salt in the isotonis will get rid of unpleasant symptoms. Nausea and muscle spasms occur due to improper intensity of training, unbalanced nutrition and insufficient consumption of water.

How to avoid a lack of salts in the body

On average, a Russians eats 3,400 milligrams grams of salt a day. This is higher than the norm recommended by The federal government’s Dietary Guidelines for Americans — no more than 2,300 mg (1 teaspoon). So most likely, the body does not need additional salt in the form of isotonic drinks or salt tablets. For athletes, the norm is slightly higher and depends on how much salt you lose during training. Here the indicators will be different for everyone. If you want to understand in more detail, you can take an analysis of the level of all electrolytes in the blood.

To maintain the water-salt balance during the race, you need to consume enough water: every 15-20 minutes 100-300 ml of water. However, the body will tell you the exact amount on its own. Focus on your sweating and calculate your drinking so that the loss of body weight after training or racing is 1-2.5%.

For prevention, you can use salt 2-3 hours before the race. 3 grams of salt per 600-800 ml of water is enough.

How to replace the isotonic drinks

If it is not possible to restore the water-salt in another way, then you can make a home isotonic drink. In terms of composition, it will be minimally different from the purchased one and will save you money.


  • 500 ml of water,
  • 5 g of salt,
  • 1 teaspoon sweetener: honey, maltodextrin or dextrin,
  • 15 ml of lemon juice.

How to cook:
Dissolve the salt in the water and mix thoroughly. Then add the remaining ingredients and mix as well.

Drink homemade isotonic drinks a couple of hours before the race, and during the race — regular water.

Isotonic drink is an additional source of salt for an athlete during intense training and racing. But in order for the body to cope with the load and retain more valuable substances, it is much more important to drink enough water: every 15-20 minutes 100-300 ml of water. 
How do you feel about isotonic drink — do you consume it or choose water?