title: Effect of dual beta-blockade and calcium antagonism on endurance performance.
abstract: The effect of oral clinically used doses of propranolol, atenolol, nifedipine, propranolol + nifedipine, and atenolol + nifedipine on endurance performance and ventilatory responses to graded treadmill testing was studied in 12 healthy physically active men. Maximal exercise duration was reduced by propranolol (8.5%, P less than 0.001) and its combination with nifedipine (11.1%, P less than 0.001), and to a lesser degree by atenolol (3.2%, 0.05 less than P less than 0.1), nifedipine (2.1%, P less than 0.05), and atenolol + nifedipine (3.9%, P less than 0.01). Exercise duration and heart rate (HR) and ventilatory responses to maximal exercise were equivalent with a beta-blocker and its combination with nifedipine. At submaximal exercise, beta-blockade reduced the HR and oxygen uptake, nifedipine accentuated the HR but did not alter ventilation, and all drugs modified the relative oxygen uptake corresponding to 85% of the maximal HR. Physiologic responses to submaximal exercise during combination therapy were similar to those during beta-blockade alone. This study concludes that, in physically active men, nifedipine induces a small impairment of maximal performance, but does not accentuate the reduction in effort tolerance resulting from beta-blockade. Furthermore, HR and ventilatory responses to exercise during combined beta-blockade and calcium antagonism can be predicted from those during beta-blockade alone.
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000328:Adult; D004311:Double-Blind Method; D004347:Drug Interactions; D005080:Exercise Test; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D009543:Nifedipine / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects; D010807:Physical Endurance / Q000187:drug effects*; D005082:Physical Exertion / Q000187:drug effects; D011897:Random Allocation
chemical_list: D000319:Adrenergic beta-Antagonists; D009543:Nifedipine