Document Detail

Accumulation of 2H2O in plasma and eccrine sweat during exercise-heat stress.
MedLine Citation:
PMID:  19841933     Owner:  NLM     Status:  MEDLINE    
The purpose of this research was to characterize the movement of ingested water through body fluids, during exercise-heat stress. Deuterium oxide ((2)H(2)O) accumulation in plasma and eccrine sweat was measured at two sites (back and forehead). The exercise of 14 males was controlled via cycle ergometry in a warm environment (60 min; 28.7 degrees C, 51%rh). Subjects consumed (2)H(2)O (0.15 mg kg(-1), 99.9% purity) mixed in flavored, non-caloric, colored water before exercise, then consumed 3.0 ml kg(-1) containing no (2)H(2)O every 15 min during exercise. We hypothesized that water transit from mouth to skin would occur before 15 min. (2)H(2)O appeared rapidly in both plasma and sweat (P < 0.05), within 10 min of water consumption. The ratio (2)H(2)O/H(2)O (D:H) was 47.3-55.0 times greater in plasma than in back sweat at minutes 10, 20, and 30 (DeltaD:H relative to baseline). At elapsed minute 20, the mean rate of deuterium accumulation (DeltaD:H min(-1)) in plasma was 14.9 and 23.7 times greater than in forehead and back sweat samples, respectively. Mean (+/-SE) whole-body sweat rate was 1.04 +/- 0.05 L h(-1) and subjects with the greatest whole-body sweat rate exhibited the greatest peak deuterium enrichment in sweat (r(2) = 0.87, exponential function); the peak (2)H(2)O enrichment in sweat was not proportional (P > 0.05) to body mass, volume of the deuterium dose, or total volume of fluid consumed. These findings clarify the time course of fluid movement from mouth to eccrine sweat glands, and demonstrate considerable differences of (2)H(2)O enrichment in plasma versus sweat.
Lawrence E Armstrong; Jennifer F Klau; Matthew S Ganio; Brendon P McDermott; Susan W Yeargin; Elaine C Lee; Carl M Maresh
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-10-20
Journal Detail:
Title:  European journal of applied physiology     Volume:  108     ISSN:  1439-6327     ISO Abbreviation:  Eur. J. Appl. Physiol.     Publication Date:  2010 Feb 
Date Detail:
Created Date:  2010-01-20     Completed Date:  2010-04-08     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100954790     Medline TA:  Eur J Appl Physiol     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  477-82     Citation Subset:  IM    
Human Performance Laboratory, University of Connecticut, Storrs, CT 06269-1110, USA.
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MeSH Terms
Body Fluids / metabolism
Body Temperature Regulation / physiology
Deuterium Oxide / metabolism*
Exercise / physiology*
Exercise Test
Hot Temperature*
Plasma / metabolism*
Sweat / metabolism*
Time Factors
Reg. No./Substance:
7789-20-0/Deuterium Oxide

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

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