Effects of diltiazem or propranolol during exercise training of hypertensive men

This was a prospective, randomized, double-blind, placebo-controlled trial to establish whether beta blockers or calcium-channel blockers limit exercise capacity and training responses in men with mild hypertension. Circuit weight and aerobic training was used to assess the effects of drugs on cardiovascular fitness and muscle strength. Fifty-two sedentary men, ages 25-59 yr, with a diastolic blood pressure of 90-105 mm Hg off drugs, without significant ST depression during maximal stress testing, received diltiazem, propranolol, or placebo. Maximal oxygen uptake (V̇O(2max)) and exercise duration during treadmill testing, as well as one-repetition maximal strength, were assessed on eight weight machines after a single-blind placebo baseline, after 2 wk of drug run-in, and after 10 wk of exercise training. Total daily doses were 240 mg for propranolol and 360 mg for diltiazem. Propranolol decreased V̇O(2max) after drug run-in (P < 0.05). Exercise training increased V̇O(2 max) (P < 0.05) in the diltiazem and placebo groups. After training, V̇O(2max) in the propranolol group increased (P < 0.05) from run-in but not beyond baseline levels. Thus, the reduction of V̇O(2max) consequent to propranolol therapy limited the overall benefits of training. Exercise duration did not change with run-in and increased (P < 0.05) with training by 22%, 19%, and 10% for the diltiazem, placebo, and propranolol groups, respectively. Strength after run-in was unchanged, and exercise training increased strength (P < 0.0001) on all weight machines in all groups. The results show an advantage of diltiazem to propranolol, particularly among physically active patients engaged in aerobic exercise who require antihypertensive therapy.