Document Detail


Isometric handgrip exercise improves acute neurocardiac regulation.
MedLine Citation:
PMID:  19680681     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Isometric handgrip (IHG) training (>6 weeks) has been shown to reduce resting arterial blood pressure (ABP) and improve cardiac autonomic modulation. However, the effects of a single bout of IHG on acute neurocardiac regulation remain unknown. The purpose of this study was to examine the effect of IHG exercise on nonlinear heart rate dynamics and cardiac vagal activity. Nonlinear dynamics were assessed by sample entropy, detrended fluctuation analysis (alpha(1)), and correlation dimension techniques. The 4-second exercise test was used to calculate the cardiac vagal index (CVI), an indirect measure of cardiac vagal activity. In a randomized crossover design, 18 older (70 +/- 5 years of age) subjects completed IHG exercise (four 2-min isometric contractions at 30% MVC) and a time-matched control condition. Following a single bout of bilateral IHG, there was a small reduction in systolic blood pressure (125 +/- 2 to 122 +/- 1 mmHg, P < 0.01), in addition to, a significant decrease in alpha(1) (1.42 +/- 0.12 to 1.22 +/- 0.10, P < 0.05), an increase in sample entropy (1.28 +/- 0.03 to 1.40 +/- 0.05, P < 0.001), and an increase in the CVI (1.24 +/- 0.03 to 1.29 +/- 0.03, P < 0.01). These results suggest improvements in acute cardiac autonomic modulation following a single bout of IHG. This may be mechanistically linked to the observed reductions in ABP seen in previous IHG training studies. Alternatively, these acute effects may have clinical applications and require further investigation.
Authors:
Philip J Millar; Maureen J MacDonald; Steven R Bray; Neil McCartney
Publication Detail:
Type:  Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't     Date:  2009-08-13
Journal Detail:
Title:  European journal of applied physiology     Volume:  107     ISSN:  1439-6327     ISO Abbreviation:  Eur. J. Appl. Physiol.     Publication Date:  2009 Nov 
Date Detail:
Created Date:  2009-10-27     Completed Date:  2010-02-05     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100954790     Medline TA:  Eur J Appl Physiol     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  509-15     Citation Subset:  IM    
Affiliation:
Department of Kinesiology, McMaster University, 1280 Main St W, Hamilton, ON L8S 4K1, Canada. millarpj@mcmaster.ca
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MeSH Terms
Descriptor/Qualifier:
Aged
Autonomic Nervous System / physiology*
Blood Pressure / physiology
Cardiovascular Physiological Phenomena
Cross-Over Studies
Exercise / physiology*
Female
Hand / physiology*
Hand Strength / physiology*
Heart / innervation,  physiology*
Heart Rate / physiology
Humans
Male
Time Factors

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


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