Dietary potassium and heavy exercise: effects on muscle water and electrolytes.
Eight men were studied during two 4-day exercise-dietary regimens, once under a control diet (80 mEq K+/day) and again with a diet low in K+ (25 mEq/day). Muscle K+ increased 5 to 6% as a result of the two exercise-dietary regimens, while no change was observed for muscle Na+ or Mg++. Plasma volume increased throughout the 4 days of each exercise-diet sequence, with the low K+ regimen resulting in the largest plasma volume gain (+15%) and a marked reduction in urinary K+ excretion. Despite the losses of K+ in sweat and the low K+ intake, there was a relatively small decrease in total body K+ content (less than 2% of body content). Based on these measurements of extracellular (plasma) and tissue (muscle) water and electrolytes, we have concluded that in combination with 4 days of heavy exercise and sweating, a low K+ diet will not significantly diminish the total body K+ content.
D000328:Adult; D001834:Body Water / Q000378:metabolism*; D002712:Chlorides / Q000652:urine; D004032:Diet; D004573:Electrolytes / Q000378:metabolism*; D006358:Hot Temperature; D006801:Humans; D008297:Male; D009132:Muscles / Q000378:metabolism*; D009318:Natriuresis / Q000187:drug effects; D005082:Physical Exertion; D011188:Potassium / Q000008:administration & dosage / Q000494:pharmacology*; D013542:Sweat / Q000032:analysis
D002712:Chlorides; D004573:Electrolytes; D011188:Potassium