Blood Electrolyte Homeostasis of Rat after High-intensive Swimming Training

In sports medicine, very little attention has been given to magnesium compared with potassium and calcium. Magnesium ions (Mg²⁺) play a central role of neuronal activity, cardiac excitability, neuromuscular transmission, muscular contraction, vasomotor tone, and blood pressure significantly related to physical performance. Exercise is a potent stressor that appears to lead to magnesium depletion through alterations on blood magnesium levels as well as increased sweat and urine excretion. After exhausted swimming (3-4 hrs) in rats, the iCa²⁺/iMg²⁺ were significantly decreased. The Na⁺, iCa²⁺, iMg²⁺, and anion gap were significantly increased. These data suggest that exercise could alter blood iMg²⁺, iCa²⁺ and the ratio of iCa²⁺/iMg²⁺ and point to important uses for iMg²⁺ and the ratio of iCa²⁺/iMg²⁺ during the training and examination of athletic performance in sports medicine.