[Biochemical changes after endurance exercise in children and juveniles (author's transl)].

In 6 groups of children and juveniles (aged 8-16 ys) the exercise induced changes (cross country skiing of different durations) in various blood-parameters (Na, K, Ca, Mg, glucose, lactic acid, free fatty acids, glycerol, triglycerides, cholesterol, urea, CK-activity) are shown in contrast to changes in adults. It was found, that there are differences in the matabolic behaviour of the groups examined; previous data in adults must be applied, with restrictions, to results found in children or juveniles. Single parameters are not sufficient to obtain informations about influences of intensive endurance training in juveniles. Remarkable changes after long-lasting exercise must be expected in the blood values of K, Mg, urea, insulin and STH.