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| Martinelli,F.S.; Chacon-Mikahil,M.P.T.; Martins,L.E.B.; Lima-Filho,E.C.; Golfetti,R.; Paschoal,M.A.; Gallo-Junior,L.. |
| The purpose of the present study was to determine if autonomic heart rate modulation, indicated by heart rate variability (HRV), differs during supine rest and head-up tilt (HUT) when sedentary and endurance-trained cyclists are compared. Eleven sedentary young men (S) and 10 trained cyclists (C) were studied. The volunteers were submitted to a dynamic ECG Holter to calculate HRV at rest and during a 70º HUT. The major aerobic capacity of athletes was expressed by higher values of <img src="/img/revistas/bjmbr/v38n4/Vo.gif">at anaerobic threshold and peak conditions (P < 0.05). At rest the athletes had lower heart rates (P < 0.05) and higher values in the time domain of HRV compared with controls (SD of normal RR interval, SDNN, medians): 59.1... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Endurance; Power spectral analysis; Heart rate variability; Autonomic heart rate modulation; Training bradycardia; Orthostatic stress. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000400019 |
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| Chacon-Mikahil,M.P.T.; Forti,V.A.M.; Catai,A.M.; Szrajer,J.S.; Golfetti,R.; Martins,L.E.B.; Lima-Filho,E.C.; Wanderley,J.S.; Marin-Neto,J.A.; Maciel,B.C.; Gallo-Jr.,L.. |
| We investigated the effects of aerobic training on the efferent autonomic control of heart rate (HR) during dynamic exercise in middle-aged men, eight of whom underwent exercise training (T) while the other seven continued their sedentary (S) life style. The training was conducted over 10 months (three 1-h sessions/week on a field track at 70-85% of the peak HR). The contribution of sympathetic and parasympathetic exercise tachycardia was determined in terms of differences in the time constant effects on the HR response obtained using a discontinuous protocol (4-min tests at 25, 50, 100 and 125 watts on a cycle ergometer), and a continuous protocol (25 watts/min until exhaustion) allowed the quantification of the parameters (anaerobic threshold, VO2 AT;... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sympathetic modulation of heart rate; Dynamic exercise; Aerobic training; Autonomic nervous system; Anaerobic threshold; Middle-aged men. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000500016 |
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| Catai,A.M.; Chacon-Mikahil,M.P.T.; Martinelli,F.S.; Forti,V.A.M.; Silva,E.; Golfetti,R.; Martins,L.E.B.; Szrajer,J.S.; Wanderley,J.S.; Lima-Filho,E.C.; Milan,L.A.; Marin-Neto,J.A.; Maciel,B.C.; Gallo-Junior,L.. |
| The purpose of the present study was to evaluate the effects of aerobic physical training (APT) on heart rate variability (HRV) and cardiorespiratory responses at peak condition and ventilatory anaerobic threshold. Ten young (Y: median = 21 years) and seven middle-aged (MA = 53 years) healthy sedentary men were studied. Dynamic exercise tests were performed on a cycloergometer using a continuous ramp protocol (12 to 20 W/min) until exhaustion. A dynamic 24-h electrocardiogram was analyzed by time (TD) (standard deviation of mean R-R intervals) and frequency domain (FD) methods. The power spectral components were expressed as absolute (a) and normalized units (nu) at low (LF) and high (HF) frequencies and as the LF/HF ratio. Control (C) condition: HRV in TD... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Heart rate variability; Power spectral density analysis; Anaerobic threshold; Aerobic exercise training; Autonomic nervous system and aging processes in man. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000600016 |
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