Armstrong L E, Costill D L, Fink W J, Bassett D, Hargreaves M, Nishibata I, King D S
Eur J Appl Physiol Occup Physiol. 1985;54(4):391-7. doi: 10.1007/BF02337183.
It has been suggested that renal conversion of sodium (Na+) during training in hot environments results in potassium (K+) deficiencies. This investigation examined the influence of two levels of dietary Na+ intake (399 vs 98 mmol X d-1) on intramuscular, urinary, sweat, and whole body K+ homeostasis. Nine unacclimated, untrained males underwent heat acclimation during two 8 day dietary-exercise regimens (40.1 +/- 0.1 degrees C, 23.5 +/- 0.4% RH). Both diets resulted in depressed urinary K+ excretion. Sweat K+ and muscle K+ concentrations were not altered by diets or acclimation. The whole body stores of Na+ increased 31.1% (+916.8 mmol) during the high Na+ diet and decreased 7.8% (-230.4 mmol) during the low Na+ diet; whole body stores of K+ increased 4.1% (+137.6 mmol) during the high Na+ diet and increased 3.4% (+113.6 mmol) during the low Na+ diet. This dietary-acclimation protocol did not result in whole-body or intramuscular K+ deficits and offers no evidence to support previous claims that dietary sodium levels affect K+ balance.
有人认为，在炎热环境中训练期间肾脏对钠（Na+）的转化会导致钾（K+）缺乏。本研究考察了两种膳食钠摄入量水平（399 vs 98 mmol·d-1）对肌肉内、尿液、汗液及全身钾稳态的影响。九名未适应、未受过训练的男性在两种为期8天的饮食 - 运动方案（40.1±0.1℃，23.5±0.4%相对湿度）期间进行热适应。两种饮食均导致尿钾排泄减少。饮食或热适应对汗液钾和肌肉钾浓度无影响。高钠饮食期间全身钠储备增加31.1%（+916.8 mmol），低钠饮食期间减少7.8%（-230.4 mmol）；高钠饮食期间全身钾储备增加4.1%（+137.6 mmol），低钠饮食期间增加3.4%（+113.6 mmol）。这种饮食 - 热适应方案未导致全身或肌肉内钾缺乏，也没有证据支持先前关于膳食钠水平影响钾平衡的说法。
