A carefully composed concentrate for the preparation of isotonic drink in a powder, with a recipe enriched by the addition of L-carnitine and L-glutamine, which additionally support the body during long-term physical exercise. An isotonic drink, due to its optimum, close to body fl uid concentration of carbohydrates and electrolytes, hydrates the body a lot more quickly and quenches thirst, contributing to the maintenance of the appropriate electrolyte balance of the body. The optimum composition of the product allows to prepare a drink that intensively hydrates the body, and which restores the water-electrolyte balance in the body during exercise.