Document Detail


Cardiac vagal activity following three intensities of exercise in humans.
MedLine Citation:
PMID:  19744086     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Cardioprotective benefits of exercising at vigorous intensities are known, but reservations remain in prescribing such activity to the untrained population, due to a perceived risk of cardiac events. Few studies have investigated the recovery of the autonomic nervous system (ANS) after a single exercise bout, especially following vigorous exercise in healthy, young but untrained individuals. In this study, the recovery of the ANS, in particular indices of vagal activity were measured postexercise, at three intensities similar to current international recommendations for health. Thirteen individuals (six females, 22.2 +/- 3.1 years) performed three 20-min constant load tests lying supine on a modified bicycle ergometer at the following intensities: moderate (2 mmol l(-1) blood lactate concentration, BLC); hard (3 mmol l(-1)BLC); and vigorous (4 mmol l(-1)BLC) as derived from a maximal test. ECG data were collected during 5-min epochs at baseline then at: 5, 15, 30, 45 and 65-min postexercise. Heart rate variability (HRV) analysis was performed to obtain R-R interval, standard time [root mean square of successive differences (RMSSD)] and frequency measures [natural logarithm of high (lnHF) and low frequency (lnHF)]. RMSSD, lnHF, lnLF and total power were reduced 5-min postexercise following all three intensities (P<0.01). Decreases persisted up to 15-min postexercise following hard and vigorous exercise only (P<0.01). In untrained young adults, parasympathetic reactivation is reduced up to 5-min postexercise regardless of intensity, returning to baseline by 30 min even after vigorous exercise. In this population, the benefits of exercise outweigh any risks of cardiac events that may be evoked by a reduction in the influence of vagal activity.
Authors:
V F Gladwell; G R H Sandercock; S L Birch
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Publication Detail:
Type:  Journal Article     Date:  2009-09-10
Journal Detail:
Title:  Clinical physiology and functional imaging     Volume:  30     ISSN:  1475-097X     ISO Abbreviation:  Clin Physiol Funct Imaging     Publication Date:  2010 Jan 
Date Detail:
Created Date:  2010-01-21     Completed Date:  2010-03-30     Revised Date:  2013-05-20    
Medline Journal Info:
Nlm Unique ID:  101137604     Medline TA:  Clin Physiol Funct Imaging     Country:  England    
Other Details:
Languages:  eng     Pagination:  17-22     Citation Subset:  IM    
Affiliation:
Centre for Sport and Exercise Science, Biological Sciences, Wivenhoe Park, University of Essex, Colchester, UK. vglad@essex.ac.uk
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MeSH Terms
Descriptor/Qualifier:
Adult
Exercise / physiology*
Exercise Test
Female
Heart / innervation*,  physiology*
Heart Rate / physiology
Humans
Male
Parasympathetic Nervous System / physiology
Sinoatrial Node / innervation,  physiology
Sympathetic Nervous System / physiology
Vagus Nerve / physiology*
Young Adult

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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