Metabolic processes und adrenocortical activity during marathon races

14 first class marathon runners were studied before and after the race. The obtained results showed that the marathon race caused a significant decrease of the excretion of 17-hydrocorticoids and 17-ketosteroids and a lowered blood cortisol level. These changes were not observed in the two best runners. Any typical changes in the affinity between the plasma proteins and cortisol were not seen. The urine content of sodium decreased while the content of potassium increased. Significant changes in blood electrolyte content were not observed. It was calculated that the loss of potassium during the marathon race amounted to 50% of the total potassium in the extracellular fluid. In contrary of the changes in urine content, the sodium content in saliva increased.