Military flight experience and sympatho-adrenal activity.

Urine excretion levels of adrenaline (A) and noradrenaline (NA) were determined, and achievement, commitment to the task, difficulty, risk, activation, and tension were rated after the preparation or planning and after the performance of 245 missions by 21 attack pilots. The catecholamine excretion levels increased and the ratio NA/A decreased as a function of condition (lesson, preparation, and mission). From a confirmatory factor analysis it was found that the catecholamine reactivity during preparation (values corrected for basal activity) was affected by the perceived challenge potential of the mission. The reference A activity covaried with the total A reactivity during the missions, i.e., the higher the basal excretion levels the higher the reactions to the missions. A positive relationship was found between former flight experience (hours) and mean activity of A. The rate of increase of A was potentiated by nicotine. Potential explanations of the increase of A are discussed.