The effect of acute versus chronic treatment with b-adreoceptor blockade on exercise performance, hemodynamic and metabolic parameters in healthy men and women

Variable results have been reported on the effect of β‐adrenoceptor blockers on maximal oxygen uptake (Vo2 max) and exercise endurance. This may in part be due to different subject populations, but it could also be due to an adaption of metabolic and haemodynamic responses to exercise during chronic treatment with β‐adrenoceptor blockers. The present study was therefore carried out to examine the effect of acute and chronic administration of the non‐selective β‐adrenoceptor blocker propranolol on both peak Vo2 and exercise performance in the same subjects. Since the effect of β‐adrenoceptor blockade has not been properly investigated in women, eight healthy women were compared with seven men. Progressive bicycle exercise to exhaustion was performed after propranolol 0.15 mg kg‐1 i.v. (acute) or 80 mg three times daily for 2 weeks (chronic) or placebo given according to a double‐blind crossover design. Mean (s.e. mean) peak Vo2, was significantly reduced from 42.3 (1.6) ml min‐1 kg‐1 during placebo to 40.3 (1.2, P <0.05)ml min‐1 kg‐1 after acute and 39.1 (1.2, P <0.001) ml min‐1 kg‐1 after chronic propranolol treatment. No significant difference in peak Vo2, between the two propranolol treatment regimens was observed (mean difference 1.2, 95% CI ‐0.1 to 2.4 ml min‐1...