Document Detail

Effect of blood volume on sweating rate and body fluids in exercising humans.
MedLine Citation:
PMID:  7319888     Owner:  NLM     Status:  MEDLINE    
Five relatively fit men performed cycle ergometer exercise (65-70% VO2max) for up to 30 min at 30 degrees C, 40% rh. The data from control (normo-volemic), hypovolemic [8.7% reduction in blood volume (BV) induced by diuretics], and hypervolemic [7.9% expansion of BV induced by infusion if isotonic serum albumin] tests revealed significant effects of BV on body fluid and sweating responses. During control exercise, BV decreased an average (+/- SE) 370 +/- 64 ml at 20 min. A significantly smaller loss occurred after 20 min of hypovolemic exercise (270 +/- 29 ml). The decrease in BV during 30 min of hypervolemic exercise (541 +/- 43 ml) was significantly greater than during control (421 +/- 50 ml). Blood volume reduction also significantly altered the control of sweating rate independent of changes in plasma osmolality. The slope of the sweating rate-to-esophageal temperature relationship (SR/Tes) was significantly reduced from the mean value of 1.07 +/- 0.16 and 1.09 +/- 0.18 mg X min-1 X cm-2 X degrees C-1 during control tests, measured from the chest and arm, respectively, to 0.64 +/- 0.11 and 0.63 +/- 0.11 mg X min-1 X cm-2 X degrees C-1 during hypovolemia. The SR/Tes slope was unchanged in hypovolemia over active tissues (calf). Hypervolemia had no effect on the control of sweating at any site. Both the body fluid and sweating responses during hypovolemia act to conserve circulating blood volume during exercise.
S M Fortney; E R Nadel; C B Wenger; J R Bove
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology: respiratory, environmental and exercise physiology     Volume:  51     ISSN:  0161-7567     ISO Abbreviation:  J Appl Physiol Respir Environ Exerc Physiol     Publication Date:  1981 Dec 
Date Detail:
Created Date:  1982-03-22     Completed Date:  1982-03-22     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  7801242     Medline TA:  J Appl Physiol Respir Environ Exerc Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1594-600     Citation Subset:  IM; S    
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MeSH Terms
Blood Volume*
Body Fluids / physiology*
Body Temperature Regulation
Diuretics / pharmacology
Hot Temperature
Osmolar Concentration
Physical Exertion*
Plasma Volume
Sodium / blood
Grant Support
Reg. No./Substance:
0/Diuretics; 7440-23-5/Sodium

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

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