An isotonic drink is a liquid whose composition is adapted to that of human blood. This refers to the ratio between nutrients and the amount of liquid. Once the drink has the same osmotic pressure, it can be absorbed particularly quickly by the body.

Alcohol, for example, has a lower density than blood. For this reason, its consumption causes the cells to be squeezed out and dehydrated. This is also the reason why it is highly dangerous to exercise under the influence of alcohol.

Most people think it is necessary to buy special products to get a high quality isotonic drink. But this is not true. Usually it is sufficient to use a mixture of mineral water and a little fruit juice. For example with apple juice or coconut water.

Numerous companies have distinguished themselves in this area in recent years. Their isotonic drinks are mostly colourful and look as if they had been designed in a highly technological laboratory. But that's not true. Making such a drink is very easy and very inexpensive.