| Cardiorespiratory adaptations induced by aerobic training in middle-aged men: the importance of a decrease in sympathetic stimulation for the contribution of dynamic exercise tachycardia. | |
| | |
MedLine Citation:
|
PMID: 9698778 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
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 para-sympathetic 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; peak O2 uptake, VO2 peak; power peak) that reflect oxygen transport. The results obtained for the S and the T groups were: 1) a smaller resting HR in T (66 beats/min) when compared to S (84 beats/min); 2) during exercise, a small increase in the fast tachycardia (delta 0-10 s) related to vagal withdrawal (P < 0.05, only at 25 watts) was observed in T at all powers; at middle and higher powers a significant decrease (P < 0.05 at 50, 100 and 125 watts) in the slow tachycardia (delta 1-4 min) related to a sympathetic-dependent mechanism was observed in T; 3) the VO2 AT (S = 1.06 and T = 1.33 l/min) and VO2 peak (S = 1.97 and T = 2.47 l/min) were higher in T (P < 0.05). These results demonstrate that aerobic training can induce significant physiological adaptations in middle-aged men, mainly expressed as a decrease in the sympathetic effects on heart rate associated with an increase in oxygen transport during dynamic exercise. |
| | |
Authors:
|
M P Chacon-Mikahil; V A Forti; A M Catai; J S Szrajer; R Golfetti; L E Martins; E C Lima-Filho; J S Wanderley; J A Marin Neto; B C Maciel; L Gallo-Júnior |
Related Documents
:
|
22030098 - Substrate oxidation and cardiac performance during exercise in disorders of long chain ... 7102538 - Pindolol postmyocardial infarction study: evaluation of the drug's antiarrhythmic and a... 2244978 - When pentobarbital is the conditioned stimulus and amphetamine is the unconditioned sti... 10890608 - Shortening of cardiac action potentials in endotoxic shock in guinea pigs is caused by ... 17786378 - Longitudinal changes in heart rate-corrected measures of exercise performance in children. 7741618 - Influence of breathing technique on arterial blood pressure during heavy weight lifting. |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Brazilian journal of medical and biological research = Revista brasileira de pesquisas médicas e biológicas / Sociedade Brasileira de Biofísica ... [et al.] Volume: 31 ISSN: 0100-879X ISO Abbreviation: Braz. J. Med. Biol. Res. Publication Date: 1998 May |
Date Detail:
|
Created Date: 1998-10-20 Completed Date: 1998-10-20 Revised Date: 2008-11-21 |
Medline Journal Info:
|
Nlm Unique ID: 8112917 Medline TA: Braz J Med Biol Res Country: BRAZIL |
Other Details:
|
Languages: eng Pagination: 705-12 Citation Subset: IM |
Affiliation:
|
Laboratório de Fisiologia do Exercício, Faculdade de Educação Física, Universidade Estadual de Campinas, SP, Brasil. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adaptation, Physiological* Exercise* Heart Rate / physiology* Humans Male Middle Aged Parasympathetic Nervous System Physical Exertion* Sympathetic Nervous System* |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: The hyperinsulinemia produced by concanavalin A in rats is opioid-dependent and hormonally regulated...
Next Document: Malaria vaccine: roadblocks and possible solutions.