Journal of Applied Physiology, Vol 66, Issue 4 1886-1895, Copyright © 1989 by American Physiological Society

ARTICLES

Influence of physical training on heart rate variability and baroreflex circulatory control

D. R. Seals and P. B. Chase
Department of Exercise and Sport Sciences, University of Arizona, Tucson 85721.

Nineteen males (aged 45-68 yr) were studied before and after either a period of regular endurance exercise [walk/jog 3-4 days/wk for 30 +/- 1 (SE) wk, n = 11] or unchanged physical activity (38 +/- 2 wk, n = 8) (controls) to determine the influence of physical training on cardiac parasympathetic (vagal) tone and baroreflex control of heart rate (HR) and limb vascular resistance (VR) at rest in middle-aged and older men. Training resulted in a marked increase in maximal O2 uptake (31.6 +/- 1.2 vs. 41.0 +/- 1.8 ml.kg-1.min-1, 2.56 +/- 0.16 vs. 3.20 +/- 0.18 l/min, P less than 0.05) and small (P less than 0.05) reductions in body weight (81.2 +/- 3.5 vs. 78.7 +/- 4.0 kg) and body fat (23.8 +/- 1.3 vs. 20.9 +/- 1.3%). HR at rest was slightly, but consistently, lower after training (63 +/- 2 vs. 58 +/- 1 beats/min, P less than 0.05). In general, HR variability (index of cardiac vagal tone) was greater after training. Chronotropic responsiveness to either brief carotid baroreflex stimulation (neck suction) or inhibition (neck pressure), or to non-specific arterial baroreflex inhibition induced by a hypotensive level of lower body suction, was unchanged after training. In contrast, the magnitude of the reflex increase in forearm VR in response to three levels of lower body suction was markedly attenuated after training (38-59%; P less than 0.05 at -10 and -30 mmHg; P = 0.07 at -20 mmHg). None of these variables or responses was altered over time in the controls. These findings indicate that in healthy, previously sedentary, middle-aged and older men, strenuous and prolonged endurance training 1) elicits large increases in maximal exercise capacity and small reductions in HR at rest, 2) may increase cardiac vagal tone at rest, 3) does not alter arterial baroreflex control of HR, and 4) results in a diminished forearm vasoconstrictor response to reductions in baroreflex sympathoinhibition.

This article has been cited by other articles:

				A. Ayer, V. Antic, A. G. Dulloo, B. N. Van Vliet, and J.-P. Montani Hemodynamic consequences of chronic parasympathetic blockade with a peripheral muscarinic antagonist Am J Physiol Heart Circ Physiol, August 1, 2007; 293(2): H1265 - H1272. [Abstract] [Full Text] [PDF]

				K. Martinmaki, H. Rusko, L. Kooistra, J. Kettunen, and S. Saalasti Intraindividual validation of heart rate variability indexes to measure vagal effects on hearts Am J Physiol Heart Circ Physiol, February 1, 2006; 290(2): H640 - H647. [Abstract] [Full Text] [PDF]

				K. Okazaki, K.-i. Iwasaki, A. Prasad, M. D. Palmer, E. R. Martini, Q. Fu, A. Arbab-Zadeh, R. Zhang, and B. D. Levine Dose-response relationship of endurance training for autonomic circulatory control in healthy seniors J Appl Physiol, September 1, 2005; 99(3): 1041 - 1049. [Abstract] [Full Text] [PDF]

				M. Buchheit, C. Simon, F. Piquard, J. Ehrhart, and G. Brandenberger Effects of increased training load on vagal-related indexes of heart rate variability: a novel sleep approach Am J Physiol Heart Circ Physiol, December 1, 2004; 287(6): H2813 - H2818. [Abstract] [Full Text] [PDF]

				S. G. Hood and R. L. Woods Vagal reflex actions of atrial natriuretic peptide survive physiological but not pathological cardiac hypertrophy in rat Exp Physiol, July 1, 2004; 89(4): 445 - 454. [Abstract] [Full Text] [PDF]

				F. Costes, F. Roche, V. Pichot, J.M. Vergnon, M. Garet, and J-C. Barthelemy Influence of exercise training on cardiac baroreflex sensitivity in patients with COPD Eur. Respir. J., March 1, 2004; 23(3): 396 - 401. [Abstract] [Full Text] [PDF]

				K.-i. Iwasaki, R. Zhang, J. H. Zuckerman, and B. D. Levine Dose-response relationship of the cardiovascular adaptation to endurance training in healthy adults: how much training for what benefit? J Appl Physiol, October 1, 2003; 95(4): 1575 - 1583. [Abstract] [Full Text] [PDF]

				K. L. Rennie, H. Hemingway, M. Kumari, E. Brunner, M. Malik, and M. Marmot Effects of Moderate and Vigorous Physical Activity on Heart Rate Variability in a British Study of Civil Servants Am. J. Epidemiol., July 15, 2003; 158(2): 135 - 143. [Abstract] [Full Text] [PDF]

				M. P. Tulppo, A. J. Hautala, T. H. Makikallio, R. T. Laukkanen, S. Nissila, R. L. Hughson, and H. V. Huikuri Effects of aerobic training on heart rate dynamics in sedentary subjects J Appl Physiol, July 1, 2003; 95(1): 364 - 372. [Abstract] [Full Text] [PDF]

				D. D. Christou, P. P. Jones, and D. R. Seals Baroreflex Buffering in Sedentary and Endurance Exercise-Trained Healthy Men Hypertension, June 1, 2003; 41(6): 1219 - 1222. [Abstract] [Full Text] [PDF]

				L. M. Ueno, T. Hamada, and T. Moritani Cardiac Autonomic Nervous Activities and Cardiorespiratory Fitness in Older Men J. Gerontol. A Biol. Sci. Med. Sci., September 1, 2002; 57(9): M605 - 610. [Abstract] [Full Text] [PDF]

				A. N. Senitko, N. Charkoudian, and J. R. Halliwill Influence of endurance exercise training status and gender on postexercise hypotension J Appl Physiol, June 1, 2002; 92(6): 2368 - 2374. [Abstract] [Full Text] [PDF]

				L. Such, A. Rodriguez, A. Alberola, L. Lopez, R. Ruiz, L. Artal, I. Pons, M. L. Pons, C. Garcia, and F. J. Chorro Intrinsic changes on automatism, conduction, and refractoriness by exercise in isolated rabbit heart J Appl Physiol, January 1, 2002; 92(1): 225 - 229. [Abstract] [Full Text] [PDF]

				J. M. Dekker, R. S. Crow, A. R. Folsom, P. J. Hannan, D. Liao, C. A. Swenne, and E. G. Schouten Low Heart Rate Variability in a 2-Minute Rhythm Strip Predicts Risk of Coronary Heart Disease and Mortality From Several Causes : The ARIC Study Circulation, September 12, 2000; 102(11): 1239 - 1244. [Abstract] [Full Text] [PDF]

				B M Pluim, C A Swenne, A H Zwinderman, A C Maan, A van der Laarse, J Doornbos, and E E Van der Wall Correlation of heart rate variability with cardiac functional and metabolic variables in cyclists with training induced left ventricular hypertrophy Heart, June 1, 1999; 81(6): 612 - 617. [Abstract] [Full Text]

				N'g. Kouame, A. Nadeau, Y. Lacourciere, and J. Cleroux Effects of Different Training Intensities on the Cardiopulmonary Baroreflex Control of Forearm Vascular Resistance in Hypertensive Subjects Hypertension, March 1, 1995; 25(3): 391 - 398. [Abstract] [Full Text]