Abstract
We examined the effect of training state on cardiac autonomic control in a naturalistic setting. Twenty-four vigorous exercisers were compared to age- and sex-matched sedentary controls. The regular exercisers were subjected to a 6-week training program after which they were randomized to 2 weeks of continued training or 2 weeks of detraining. Cardiac autonomic control was measured over a 24-h period by ambulatory recording, using the preejection period (PEP) and respiratory sinus arrhythmia (RSA). Nonexercising controls had a significantly higher ambulatory heart rate (HR) compared to the regular exercisers but comparable 24-h levels of PEP and RSA. In regular exercisers, 2 weeks of detraining did not significantly change the 24-h levels of HR, PEP, or RSA. We conclude that the bradycardia in healthy regular exercisers is the result of a lower intrinsic heart rate rather than a shift in cardiac autonomic balance from sympathetic to vagal control.
References
(2005). Sympathetic neural regulation in endurance-trained humans: Fitness vs. fatness. Journal of Applied Physiology, 98, 498–502.
(2003). Heart rate variability in athletes. Sports Medicine, 33, 889–919.
(1997). Heart rate variability: Origins, methods, and interpretive caveats. Psychophysiology, 34, 623–648.
(1994). Autonomic cardiac control. III. Psychological stress and cardiac response in autonomic space as revealed by pharmacological blockades. Psychophysiology, 31, 599–608.
(1972). Effects of physical training on cardiac actomyosin adenosine triphosphatase activity. The American Journal of Physiology, 223, 1486–1490.
(2002). Aerobic exercise conditioning: A nonpharmacological antiarrhythmic intervention. Journal of Applied Physiology, 92, 446–454.
(2006). Effects of endurance exercise training on heart rate variability and susceptibility to sudden cardiac death: Protection is not due to enhanced cardiac vagal regulation. Journal of Applied Physiology, 100, 896–906.
(1998). Intensive training and cardiac autonomic control in high level athletes. Medicine and Science in Sports and Exercise, 30, 691–696.
(2001). Individual differences in response to regular physical activity. Medicine and Science in Sports and Exercise, 33, S446–S451.
(1995). Association between heart rate variability and training response in sedentary middle-aged men. European Journal of Applied Physiology and Occupational Physiology, 70, 75–80.
(2005). Heart rate variability and intensity of habitual physical activity in middle-aged persons. Medicine and Science in Sports and Exercise, 37, 1530–1534.
(1997). Sleep and circadian influences on cardiac autonomic nervous system activity. AJP – Heart and Circulatory Physiology, 273, 1761–1768.
(2003). Effect of endurance exercise on autonomic control of heart rate. Sports Medicine, 33, 33–46.
(1986). Cardiac size and VO2Max do not decrease after short-term exercise cessation. Medicine and Science in Sports and Exercise, 18, 420–424.
(1993). Regular exercise and aerobic fitness in relation to psychological make-up and physiological stress reactivity. Psychosomatic Medicine, 55, 347–363.
(1995). Ambulatory measurement of respiratory sinus arrhythmia and respiration rate. Biological Psychology, 41, 205–227.
(1996). Effect of aerobic fitness training on heart rate variability and cardiac baroreflex sensitivity. Homeostasis, 37, 28–51.
(1990). Existing and training induced differences in aerobic fitness, their relationship to physiological response patterns during different types of stress. Psychophysiology, 27, 457–477.
(1993). Heart rate variability and aerobic fitness. American Heart Journal, 125, 726–731.
(1992). Neural regulation of heart rate variability in endurance athletes and sedentary controls. Cardiovascular Research, 26, 713–719.
(2007). Effect of exercise on blood pressure control in hypertensive patients. European Journal of Cardiovascular Prevention and Rehabilitation, 14, 12–17.
(2007). Effect of training and detraining on heart rate variability in healthy young men. International Journal of Sports Medicine, 564–570.
(2006). Temporal stability of ambulatory stroke volume and cardiac output measured by impedance cardiography. Biological Psychology, 72, 110–117.
(2007). Comparison of time and frequency domain measures of RSA in ambulatory recordings. Psychophysiology, 44, 203–215.
(1996). Effect of graded increases in parasympathetic tone on heart rate variability. Journal of Cardiovascular Electrophysiology, 7, 594–602.
(1997). Physical fitness as a determinant of vagal modulation. Medicine and Science in Sports and Exercise, 29, 812–817.
(1992). Comparison of 24-hour parasympathetic activity in endurance-trained and untrained young men. Journal of the American College of Cardiology, 20, 552–558.
(2000). Exercise and autonomic function. Coronary Artery Disease, 11, 129–135.
(2004). Respiratory sinus arrhythmia, cardiac vagal control, and daily activity. AJP – Heart and Circulatory Physiology, 287, H728–H734.
(2000). Heart rate variability in obese children, relations to total body and visceral adiposity, and changes with physical training and detraining. Obesity Research, 8, 12–19.
(2005). Heart rate variability in adolescents, relations to physical activity, fitness, and adiposity. Medicine and Science in Sports and Exercise, 37, 1856–1863.
(1967). Effects of adrenergic receptor activation and blockade on the systolic preejection period, heart rate, and arterial pressure in man. Journal of Clinical Investigation, 46, 1704–1714.
(1998). Respiratory sinus arrhythmia during exercise in aerobically trained and untrained men. Medicine and Science in Sports and Exercise, 30, 206–214.
(2003). Cardiovascular autonomic function correlates with the response to aerobic training in healthy sedentary subjects. American Journal of Physiology-Heart and Circulatory Physiology, 285, H1747–H1752.
(2005). Effects of variation in posture and respiration on RSA and preejection period. Psychophysiology, 42, 713–719.
(2003). Dose-response relationship of the cardiovascular adaptation to endurance training in healthy adults, how much training for what benefit?. Journal of Applied Physiology, 95, 1575–1583.
(1975). Respiratory sinus arrhythmia, noninvasive measure of parasympathetic cardiac control. Journal of Applied Physiology, 39, 801–805.
(1982). Sympathetic and parasympathetic cardiac control in athletes and nonathletes at rest. Journal of Applied Physiology, 52, 1652–1657.
(1985). Parasympathetic control of resting heart-rate – Relationship to aerobic power. Medicine and Science in Sports and Exercise, 17, 451–455.
(1992). Exercise training reduces the sympathetic component of the blood-pressure heart-rate baroreflex in man. Clinical Science, 82, 357–362.
(2000). Cardiovascular, metabolic, and plasma catecholamine responses to passive and active exercises. Journal of Physiology and Pharmacology, 51, 267–278.
(1980). Nonautonomic component in bradycardia of endurance trained men at rest and during exercise. Acta Physiologica Scandinavica, 109, 297–305.
(1987). Cardiovascular responses to stress, 2. Relationships to aerobic exercise patterns. Psychophysiology, 24, 79–86.
(1972). Autonomic nervous control of cardiac frequency in exercise-trained rat. Journal of Applied Physiology, 33, 796–799.
(2000). Controlled 5-month aerobic training improves heart rate but not heart rate variability or baroreflex sensitivity. Journal of Applied Physiology, 89, 1825–1829.
(2006). Intraindividual validation of heart rate variability indexes to measure vagal effects on hearts. AJP – Heart and Circulatory Physiology, 290, H640–H647.
(1991). Exercise training lowers resting renal but not cardiac sympathetic activity in humans. Hypertension, 18, 575–582.
(1999). The effects of epinephrine administration on impedance cardiographic measures of cardiovascular function. International Journal of Psychophysiology, 31, 189–196.
(1983). Dynamics of cardiac output and systolic time intervals in supine and upright exercise. Journal of Applied Physiology, 55, 1674–1681.
(2007). Exercise training and sympathetic nervous system activity, Evidence for physical activity dependent neural plasticity. Clinical and Experimental Pharmacology and Physiology, 34, 377–384.
(2000). Detraining, loss of training-induced physiological and performance adaptations. Part I: Short term insufficient training stimulus. Sports Medicine, 30, 79–87.
(2001). Cardiorespiratory and metabolic characteristics of detraining in humans. Medicine and Science in Sports and Exercise, 33, 413–421.
(1992). Vagal and sympathetic control of heart-rate during exercise by sedentary and exercise-trained rats. Brazilian Journal of Medical and Biological Research, 25, 1045–1052.
(1979). Preejection period: Measuring beta-adrenergic influences upon the heart. Psychophysiology, 16, 546–553.
(2002). Autonomic adaptations to intensive and overload training periods: A laboratory study. Medicine and Science in Sports and Exercise, 34, 1660–1666.
(1987). Physical activity and the incidence of coronary heart disease. Annual Review of Public Health, 8, 253–287.
(1998). Sympathetic neural adaptations to exercise training in humans: Insights from microneurography. Medicine and Science in Sports and Exercise, 30, 387–391.
(2002). Heritability of HR and BP response to exercise training in the HERITAGE family study. Medicine and Science in Sports and Exercise, 34, 972–979.
(2003). Large-scale ensemble averaging of ambulatory impedance cardiograms. Behavior Research Methods, Instruments & Computers, 35, 467–477.
(2006). Implementation and interpretation of respiratory sinus arrhythmia measures in psychosomatic medicine: Practice against better evidence?. Psychosomatic Medicine, 68, 617–627.
(2001). Exercise and autonomic function in health and cardiovascular disease. Cardiology Clinics, 19, 369–387.
(1998). Fitness and gender-related differences in heart period variability. Psychosomatic Medicine, 60, 773–781.
(2003). The effects of exercise training on sympathetic neural activation in advanced heart failure – A randomized controlled trial. Journal of the American College of Cardiology, 42, 854–860.
(1994). Effect of athletic training on heart-rate-variability. American Heart Journal, 127, 1275–1278.
(2005). Effects of exercise on heart rate variability: Inferences from meta-analysis. Medicine and Science in Sports and Exercise, 37, 433–439.
(2001). Cardiovascular indices of peripheral and central sympathetic activation. Psychosomatic Medicine, 63, 788–796.
(1999). Exercise training and heart rate variability in older people. Medicine and Science in Sports and Exercise, 31, 816–821.
(1990). Methodological guidelines for impedance cardiography. Psychophysiology, 27, 1–23.
(1986). Evaluation of beta-adrenergic influences on cardiovascular and metabolic adjustments to physical and psychological stress. Psychophysiology, 23, 89–104.
(1989). Effects of aerobic exercise training on hemodynamic responses during psychosocial stress in normotensive and borderline hypertensive type-A men – A preliminary-report. Psychosomatic Medicine, 51, 123–136.
(1995). Autonomic nervous-system control of the heart – Endurance exercise training. Medicine and Science in Sports and Exercise, 27, 1406–1413.
(1997). Autonomic differences between athletes and nonathletes: Spectral analysis approach. Medicine and Science in Sports and Exercise, 29, 1482–1490.
(1989). Exercise training bradycardia – The role of autonomic balance. Medicine and Science in Sports and Exercise, 21, 40–44.
(1999). Aerobic group training improves exercise capacity and heart rate variability in elderly patients with a recent coronary event – A randomized controlled study. European Heart Journal, 20, 1638–1646.
(1986). Altered cardiovascular responsiveness to adrenaline in endurance-trained subjects. Acta Physiologica Scandinavica, 126, 539–550.
(1991). Altered cardiovascular responsiveness to adrenoceptor agonists in endurance-trained men. Journal of Applied Physiology, 70, 531–538.
(1984). Skeletal-muscle sympathetic activity at rest in trained and untrained subjects. Acta Physiologica Scandinavica, 120, 499–504.
. (1996). Heart rate variability: Standards of measurement, physiological interpretation, and clinical use. Circulation, 93, 1043–1065.
(2004). Physical training and heart rate and blood pressure variability: A 5-yr randomized trial. American Journal of Physiology-Heart and Circulatory Physiology, 286, H1821–H1826.
(1996). Noninvasive evaluation of sympathovagal balance in athletes by time and frequency domain analyses of heart rate and blood pressure variability. Clinical Physiology, 16, 575–588.
(1989). Aerobic fitness and the cardiovascular response to stress. Psychophysiology, 26, 17–28.
(1997). Effects of chronic exercise and deconditioning on platelet function in women. Journal of Applied Physiology, 83, 2080–2085.
(2007). Heart rate variability as a predictor of negative mood symptoms induced by exercise withdrawal. Medicine and Science in Sports and Exercise, 39, 735–741.
(1996). Ambulatory monitoring of the impedance cardiogram. Psychophysiology, 33, 184–193.
(2001). Physical fitness and activity as separate heart disease risk factors: A meta-analysis. Medicine and Science in Sports and Exercise, 33, 754–761.
(1999). Secretory immunoglobulin A and cardiovascular reactions to mental arithmetic, cold pressor, and exercise: Effects of beta-adrenergic blockade. Psychophysiology, 36, 591–601.
