Effect of alpha 1-adrenoceptor blockade on maximal VO2 and endurance capacity in well-trained athletic hypertensive men.

The effect of α 1 -adrenoceptor blockade (doxazosin, 4 mg daily) on maximal VO 2 and physical endurance capacity in 16 mildly hypertensive, athletic men was investigated in a randomized, placebocontrolled, double-blind, two-period of 4 weeks, cross-over study. The maximal workload obtained during graded bicycle ergometer exercise and the corresponding maximal VO 2 were reduced by 16±3 W (mean±SE), (P=.00003) and 3±1 mL/(kg.min) (P=.0004), respectively, on doxazosin compared with placebo. The running time on a 5000 m track increased by 43±12 sec on doxazosin (P=.04). Heart rate was unchanged during the running session