Physiological and Subjective Reactions to Different Physical Work Loads

Abstract

Catecholamine excretion, cardiovascular functions, and subjective effort were studied in 10 healthy male Ss in a control condition and in three experimental sessions in each of which 5 successive 6-min. tests of either 150, 450, or 750 kpm/min., were performed on a bicycle ergometer. Catecholamine-excretion rates remained close to control levels at the lower work loads, while the highest load induced a significant increase in both adrenaline and noradrenaline output. Heart rate, systolic pressure, and subjective effort increased consistently with increasing work load.