The 3 most important aspects to evaluate in an isotonic drink are:
The osmolarity, It must be an isotonic drink, that is, the osmolarity of the drink must be between 270 and 330 milliOsmoles/liter.
Gsn isotonic has an osmolarity of 280 mOsm/l
Electrolytes, It must contain at least sodium, potassium and magnesium. Sodium is the electrolyte that is lost in the greatest amount during sports, especially through sweat.
Helps the normal functioning of muscles and nerves. If it is not properly replenished, it ends up causing hyponatremia, that is, a low level of sodium in the body that is responsible, among other aspects, for the appearance of cramps or muscle spasms.
There are also other electrolytes or mineral salts that must also be present in an isotonic drink, such as potassium and magnesium. Both electrolytes are essential to maintain the optimal functioning of the muscular activity of the organism.
Carbohydrates, Glucose is the preferred carbohydrate that should be part of an isotonic drink, because it is absorbed immediately and once in the body it is easily and quickly used by the muscle to provide energy.
In addition, the presence of glucose oligosaccharides should be assessed. Its presence allows better control of the isotonicity of the drink, bothers the stomach less during training sessions and also produces a more gradual passage of glucose into the blood than pure glucose and therefore, will have an effect on the athlete more sustained.