Physiological changes during physical and psychological stress

Abstract

Changes in urine catecholamines, blood pressure and heart rate during two physical exercise test sessions (35% VO_2max and 50% VO_2max) and one psychological stress session which involved reading under delayed auditory feedback (DAF) were compared. Increases in both the haemodynamic parameters and in the excretion of catecholamines were found in response to all three tests. The changes in adrenaline (A) did not differentiate between the test situations. Noradrenaline (NA) levels were significantly larger for physical exercise conditions and graded according to the relative workload. The ratio ΔNA/ΔA was similar for both physical tests but statistically different for the DAF session. Significant and positive correlations between haemodynamic parameters and catecholamine excretion were found only for the DAF test. These correlations and the differences in catecholamine excretion suggest different bodily responses to physical and psychological stress. These findings may have practical implications in industrial field studies.