| Circadian variation in the circulatory responses to exercise: relevance to the morning peaks in strokes and cardiac events. | |
| | |
MedLine Citation:
|
PMID: 19826832 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Sudden cardiac and cerebral events are most common in the morning. A fundamental question is whether these events are triggered by the increase in physical activity after waking, and/or a result of circadian variation in the responses of circulatory function to exercise. Although signaling pathways from the master circadian clock in the suprachiasmatic nuclei to sites of circulatory control are not yet understood, it is known that cerebral blood flow, autoregulation and cerebrovascular reactivity to changes in CO(2) are impaired in the morning and, therefore, could explain the increased risk of cerebrovascular events. Blood pressure (BP) and the rate pressure product (RPP) show marked 'morning surges' when people are studied in free-living conditions, making the rupture of a fragile atherosclerotic plaque and sudden cardiac event more likely. Since cerebral autoregulation is reduced in the morning, this surge in BP may also exacerbate the risk of hemorrhagic and ischemic strokes in the presence of other acute and chronic risk factors. Increased sympathetic activity, decreased endothelial function, and increased platelet aggregability could also be important in explaining the morning peak in cardiac and cerebral events but how these factors respond to exercise at different times of day is unclear. Evidence is emerging that the exercise-related responses of BP and RPP are increased in the morning when prior sleep is controlled. We recommend that such 'semi-constant routine' protocols are employed to examine the relative influence of the body clock and exogenous factors on the 24-h variation in other circulatory factors. |
| | |
Authors:
|
Greg Atkinson; Helen Jones; Philip N Ainslie |
Publication Detail:
|
Type: Journal Article Date: 2009-10-14 |
Journal Detail:
|
Title: European journal of applied physiology Volume: 108 ISSN: 1439-6327 ISO Abbreviation: Eur. J. Appl. Physiol. Publication Date: 2010 Jan |
Date Detail:
|
Created Date: 2010-01-21 Completed Date: 2010-04-30 Revised Date: 2010-09-27 |
Medline Journal Info:
|
Nlm Unique ID: 100954790 Medline TA: Eur J Appl Physiol Country: Germany |
Other Details:
|
Languages: eng Pagination: 15-29 Citation Subset: IM |
Affiliation:
|
Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK. g.atkinson@ljmu.ac.uk |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Age Factors Blood Flow Velocity / physiology Blood Pressure / physiology Brain / physiology Brain Ischemia / epidemiology, physiopathology Cerebrovascular Circulation / physiology Circadian Rhythm / physiology* Endothelium, Vascular Exercise / physiology* Hand Strength Humans Motor Activity / physiology Myocardial Infarction / epidemiology* Physical Endurance / physiology Physical Exertion Risk Factors Sleep Stroke / epidemiology, physiopathology* Suprachiasmatic Nucleus / physiopathology Sympathetic Nervous System / physiology* Time Factors |
| Grant Support | |
ID/Acronym/Agency:
|
G0501286(75373)//Medical Research Council |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Lung surfactant proteins in the early human placenta.
Next Document: Can HRV be used to evaluate training load in constant load exercises?