Effect of sodium and water intake on plasma aldosterone during prolonged exercise in warm environment

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dc.contributor.advisor Costill, David L. en_US
dc.contributor.author Shi, Xiaocai en_US
dc.date.accessioned 2011-06-03T19:35:20Z
dc.date.available 2011-06-03T19:35:20Z
dc.date.created 1990 en_US
dc.date.issued 1990
dc.identifier LD2489.Z72 1990 .S55 en_US
dc.identifier.uri http://cardinalscholar.bsu.edu/handle/handle/183960
dc.description.abstract Eight well-trained male and female cyclists were studied to determine the effect of sodium and/or water intake on plasma aldosterone during six hours of cycling (55% VO2max) in a warm environment (Tdb = 350C WBGT = 30°C). Each subject randomly completed three trials (water = W; saline = S and no fluid = NF) at one week intervals. Venous blood samples were obtained before dehydration, at 2, 4, 5 and 6 hours during exercise, and also after dehydration. Plasma samples were analyzed for hemoglobin, sodium, potassium, aldosterone and osmolality. Sweat and urine samples were also collected and analyzed for sodium content. Plasma volume based on hemoglobin decreased significantly ( P < 0.01 ) at 15 min in all three trials (Trial W = -7.6%±1.12%; Trial S = -8.6%±1.42% and Trial NF = -6.7%±0.88%) and continued to decrease significantly in Trial NF during exercise ( -10.99% ± 1.3% at the 2th hr; -15.5% ±1.3% at the 4th hr and -16.8%±1.32% at the 5th hr).No significant differences were found betwee trials. Plasma sodium concentration [Na+] decreased over time in Trials W and S and increased in Trial NF due to plasma volume loss. Significant differences in [ Na+ ] were found between Trial NF and Trials W or S. Plasma sodium [Na+ ] adjusted by plasma volume change decreased significantly at 2 hours ( P < 0.01) in the three trials. Average total sodium content of plasma decreased by 125.9 mEq during Trial S, 223.1 mEq during Trial W and 147.1 mEq during Trial NF. Plasma potassium increased significantly (P < 0.01) at 2 hours in all three trials. Plasma osmolality increased significantly (P < 0.01) during prolonged exercise (Trial W = 287.1±2.4 mEq/l; Trial S = 289.4±1.17 mEq/1 and Trial NF = 306±1.6 mEq/1). No significant differences were found between Trials W and S although osmolality was lower in Trial W than in Trial S. A significant difference in osmolality was obtained between Trial NF and Trials W and S (P < 0.01). Plasma aldosterone increased significantly (P < 0.01) during exercise and decreased after exercise. No significant differences existed between Trials W and S although aldosterone levels were lower in Trial S than in Trial W. However, a significant difference was found between Trial NF and Trials W or S. The results of this study suggest that plasma aldosterone has an inverse relationship with plasma volume changes and total sodium concentrations. An increase in plasma potassium and a decrease in plasma sodium during prolonged exercise in a warm environment significantly enhanced plasma aldosterone concentration. The intake of water significantly decreased plasma aldosterone during prolonged exercise in a warm environment, but the intake of sodium had no significant effect in this study.
dc.description.sponsorship School of Physical Education
dc.format.extent viii, 55 leaves : ill. ; 28 cm. en_US
dc.source Virtual Press en_US
dc.subject.lcsh Aldosterone -- Physiological effect. en_US
dc.subject.lcsh Sodium -- Physiological effect. en_US
dc.subject.lcsh Exercise -- Physiological aspects. en_US
dc.title Effect of sodium and water intake on plasma aldosterone during prolonged exercise in warm environment en_US
dc.description.degree Thesis (M.A.)
dc.identifier.cardcat-url http://liblink.bsu.edu/catkey/722232 en_US

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  • Master's Theses [5510]
    Master's theses submitted to the Graduate School by Ball State University master's degree candidates in partial fulfillment of degree requirements.

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