[Endurance after propranolol in the human execution of a general dynamic exercise]

The effects of a single oral dose of 40 mg propranolol on endurance time and on the maximum oxygen consumption were studied in eight healthy young men. They were running on a motor-driven treadmill (work rate from 80 to 150% VO2 max. The VO2 max and endurance time were decreased to an average of 10 and 30% of controls respectively. The relationship between the endurance time and the relative work load (VO2/VO2 max) remained unchanged after beta-adrenoceptor blockade. The reduction of the endurance time following beta-adrenoceptor blockade is a consequence of the reduction of the VO2 max.