Changes in stroke volume with beta -blockade before and after 10 days of exercise training in men and women

• Published in: Journal of applied physiology (1985) Vol. 83; no. 5; pp. 1660 - 1665
• Main Authors: Mier, Constance M, Domenick, Melissa A, Wilmore, Jack H
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Am Physiological Soc 01.11.1997; American Physiological Society
• Subjects: Adrenergic beta-Antagonists - pharmacology; Adult; Atenolol - pharmacology; Biological and medical sciences; Blood Pressure - drug effects; Cardiac Output - drug effects; Cardiac Output - physiology; Exercise Test; Female; Fundamental and applied biological sciences. Psychology; Heart; Humans; Male; Oxygen Consumption - drug effects; Physical Fitness - physiology; Sex Characteristics; Stroke Volume - drug effects; Stroke Volume - physiology; Vertebrates: cardiovascular system; Heart; Short term; Physical exercise; Human; Physical training; Bicycle ergometer; Sex; Systolic volume; Left ventricle; Blood flow; β-Adrenergic receptor; Female; Circulatory system; Antagonist; Comparative study; Adaptation
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.1997.83.5.1660

Constance M. Mier, Melissa A. Domenick, and Jack H. Wilmore Human Performance Laboratory, Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas 78712 Received 15 January 1997; accepted in final form 18 July 1997. Mier, Constance M., Melissa A. Domenick, and Jack H. Wilmore. Changes in stroke volume with -blockade before and after 10 days of exercise training in men and women. J. Appl. Physiol. 83(5): 1660-1665, 1997. We sought to determine whether 10 days of training would be a sufficient stimulus for cardiac adaptations that would allow a greater compensatory stroke volume during -blockade. We also sought to determine whether men and women had a similar cardiac reserve capacity for increasing stroke volume with -blockade during submaximal exercise. Eight men (age 29 ± 2 yr, mean ± SE) and eight women (25 ± 2 yr) cycled at 65% of peak O 2 consumption (unblocked) under placebo-control and -blockade (100 mg atenolol) conditions performed on separate days. These tests were repeated at the same power output after training (10 consecutive days, 1 h of cycling per day). Before training, -blockade significantly ( P  < 0.05) decreased heart rate (HR) and cardiac output and increased stroke volume in both men and women. After training, the increase in stroke volume and decrease in HR with -blockade was significantly less while cardiac output was reduced more. There were no gender differences in the effects of -blockade on HR, stroke volume, or cardiac output. These data indicate that, during exercise with -blockade, exercise training for 10 days does not enhance the compensatory increase in stroke volume and that men and women have a similar cardiac reserve capacity for increasing stroke volume. short-term training; atenolol; cardiac output; blood pressure 0161-7567/97 $5.00 Copyright © 1997 the American Physiological Society