Effects of dietary sodium intake on body and muscle potassium content in unacclimatized men during successive days of work in the heat

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dc.contributor.advisor Craig, Bruce W. en_US
dc.contributor.author Armstrong, Lawrence E., 1949- en_US
dc.date.accessioned 2011-06-03T19:22:38Z
dc.date.available 2011-06-03T19:22:38Z
dc.date.created 1983 en_US
dc.date.issued 1983
dc.identifier LD2489.Z68 1983 .A7 en_US
dc.identifier.uri http://cardinalscholar.bsu.edu/handle/handle/174841
dc.description.abstract This investigation examined the influence of two levels of dietary sodium (Na+) intake on intramuscular and extracellular potassium (K+) content. Nine unacclimatized college males exercised. (90 minutes of treadmill walking, 5.6km/hr, 6X grade) in an environmental chamber maintained at 40.1( + .05)°C and 23.5( + . 4) %RH, during two 8-day dietary-acclimation regimens. The first regimen employed a high Na+ diet (399mEq/day), the second a low Na+ diet (98mEq/day); both diets contained 80mEq K+/day. Total body K+ stores increased during the high Na+ diet (+138mEq, 4.1%) and the-low Na+ diet (+114mEq, 3.4%). By day 8 (D8) of both treatments, subjects exhibited a significantly lower (p<.O5) mean heart rate and rectal temperature. Oxygen consumption and sweat rate were unaltered but sweat responsiveness (ml/hr/°c) progressively increased during the acclimation trials. Plasma volume increased +16.3% (D4) and +10.7% (D8) under the high Na+ diet and only +3.0% (D4) and +7.0% (D8) under the low Na+ diet. The low sodium diet was associated with a significantly higher (p<.05) mean heart rate (D3-D5), higher rectal temperature (D3-D6), lower sweat responsiveness (D2) and a delayed plasma volume expansion (D4)--resulting in less effective heat removal. The total content of K+, Na+, and C1- in plasma changed isoosmotically with plasma volume. The diets were associated with equivalent urine K+ excretion, and. during exercise in the heat both diets resulted in significantly decreased urine K+ losses. Muscle K+ and sweat K+ concentrations were not altered by dietary intervention or acclimation trials. Total muscle water-was significantly increased, in accord with Na+ and Cl- increases, on D8 of the low Na+ diet only. It was concluded that dietary intake of Na+, in combination with 8 days. of exercise in the heat and heavy sweating, does not significantly diminish the intramuscular K+ or total body K+ content. en_US
dc.format.extent ix, 100 leaves : ill. ; 28 cm. en_US
dc.source Virtual Press en_US
dc.subject.lcsh Salt -- Physiological effect. en_US
dc.subject.lcsh Exercise -- Physiological aspects. en_US
dc.subject.lcsh Heat -- Physiological effect. en_US
dc.title Effects of dietary sodium intake on body and muscle potassium content in unacclimatized men during successive days of work in the heat en_US
dc.title.alternative Dietary sodium intake on body and muscle potassium content en_US
dc.description.degree Thesis (Ph. D.) en_US
dc.identifier.cardcat-url http://liblink.bsu.edu/catkey/411152 en_US


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  • Doctoral Dissertations [3121]
    Doctoral dissertations submitted to the Graduate School by Ball State University doctoral candidates in partial fulfillment of degree requirements.

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