Document Detail

Response to a fluid load in athletes with a history of exercise induced hyponatremia.
MedLine Citation:
PMID:  11528329     Owner:  NLM     Status:  MEDLINE    
PURPOSE: To determine whether athletes who had previously developed hyponatremia during an ultradistance triathlon show an impaired ability to excrete a large fluid load compared with athletes who had completed the same race without developing hyponatremia. METHODS: Six athletes who had developed hyponatremia ([Na] < 135 mmol x L(-1)) in the 1997 Ironman Triathlon (study cases) were compared with six athletes who completed the same race without hyponatremia (controls). All participants consumed 3.4 L of water over 2 h at rest. Weight, urine output, urine electrolytes, serum [Na(+)], hemoglobin, and hematocrit were measured every 30 min. Changes in plasma volume and residual fluid volume in the gut were estimated from these data. RESULTS: There were no significant differences between cases and controls in any parameters measured. Maximal rates of urine production (+/- SD) (1043 +/- 331 mL x h(-1) for cases, 878 +/- 168 mL x h(-1) for controls) were substantially behind the rate of fluid intake (1500 mL x h(-1)). Consequent to fluid retention, serum [Na(+)] fell progressively in both groups. Five cases and four controls developed hyponatremia. There was an inverse correlation between change in body weight and change in [Na(+)] (r = -0.67). Estimated changes in the intra- and extra-cellular fluid volumes could account for all the retained fluid, and there was little evidence for fluid accumulation in the bowel. CONCLUSION: When evaluated at rest, there does not appear to be any unique pathophysiological characteristic that explains why some athletes develop hyponatremia in response to fluid overload during prolonged exercise. Rather, hyponatremia was induced with equal effect in both cases and controls, consequent to progressive fluid overload of all the body fluid compartments and without evidence for fluid retention in the small bowel.
D B Speedy; T D Noakes; T Boswell; J M Thompson; N Rehrer; D R Boswell
Related Documents :
15266359 - Cardiovascular response to exercise in elite ice hockey players.
18607219 - Hydration recommendations for sport 2008.
11387289 - Physical activity as a possible aggravating factor for athletes with varicocele: impact...
10830679 - The efficacy of cyanoacrylate-derived surgical adhesive for use in the repair of lacera...
17311809 - Biochemical evidence of myocardial fibrosis in veteran endurance athletes.
7596029 - Evaluation of abnormal signal-averaged electrocardiograms in young athletes.
6741799 - An exponential formula for heart rate dependence of qt interval during exercise and car...
20149929 - Growth hormone, prolactin and cortisol response to exercise in patients with depression.
11035679 - Targeting aerosol deposition in patients with cystic fibrosis: effects of alterations i...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Medicine and science in sports and exercise     Volume:  33     ISSN:  0195-9131     ISO Abbreviation:  Med Sci Sports Exerc     Publication Date:  2001 Sep 
Date Detail:
Created Date:  2001-08-30     Completed Date:  2001-09-27     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8005433     Medline TA:  Med Sci Sports Exerc     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1434-42     Citation Subset:  IM; S    
Department of General Practice and Primary Care, and Department of Pediatrics, University of Auckland, New Zealand.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Exercise / physiology*
Fluid Shifts / physiology*
Hyponatremia / physiopathology*
Middle Aged
Physical Endurance
Risk Factors
Water-Electrolyte Balance / physiology*

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

Previous Document:  Risk factors for groin injuries in hockey.
Next Document:  Long-term follow-up after exertional heat illness during recruit training.