Athletes need plenty of energy, during their training. They generally cover this demand by assimilating a large amount of carbohydrates. In case the recipients of carbohydrates (glykogen) within muscle and liver are used up, the body tends to use up amino acids, in order to provide itself with new energy, so that the amino acids which have been used have necessarily to be restored, otherwise the organism would try to derive that from the muscles themselves (cataboly). The ideal supply of amino acids can support the regeneration after the training, as well as endorse the muscle growth.