[Effect of 1-alpha blockader on maximal oxygen consumption and physical endurance in hypertensive men]

The effect of alpha 1 adrenoceptor blockade (doxazosin, 4 mg daily) on maximal oxygen uptake (VO2 max) and physical endurance capacity in 16 mildly hypertensive, athletic men was investigated in a randomized, placebo-controlled, double-blind, two-period of 4 weeks, cross-over study. The maximal work load obtained during graded bicycle ergometer exercise and the VO2 max were reduced by 16 +/- 3 W (mean +/- SE) and 3 +/- 1 ml x kg-1 x min-1 on doxazosin (p < 0.001 for both), and the running time on 5000 m track increased by 43 +/- 12 sec (p < 0.05). Thus, alpha 1-blockade moderately reduces VO2 max and physical endurance capacity in mildly hypertensive athletic men. However, lower systolic blood pressure (9 +/- 4 mm Hg, p < 0.05) immediately after running, and unchanged heart rate suggest a safer performance of exercise.