“Common sports drinks like Gatorade, Allsport and Powerade are less than optimum for rehydration purposes because they contain no magnesium.” Says Dr. Robert Whang MD, Professor of Medicine at the University of Hawaii.
Dr. Whang points out that adequate levels of intracellular potassium and magnesium are important in ensuring sufficient blood flow to the muscles and internal organs, in maintaining normal acid-base balance, and in controlling the level of excitation of the nerves, particularly in the heart. Magnesium is a vital component in the synthesis of ATP (the body’s main energy source), DNA, RNA and protein, and is required for proper nerve conduction, muscle contraction, cell division, and transport across cell membranes. Magnesium losses during strenuous exercise can be quite considerable and are accompanied by significant losses of potassium as well. There is also some evidence that a magnesium deficiency can interfere with the reuptake of potassium after dehydration. The United States Army has recently developed a new rehydration beverage specifically designed for troops operating in desert and tropical environments. The new drink, Army CE 1, contains 128 mg of sodium, 96 mg of potassium, and 16 mg of magnesium per 240 ml. In comparison the popular sports drink Gatorade contains 110 mg of sodium, 30 mg of potassium, and no magnesium. Dr. Whang concludes that consideration should be given to adding magnesium to sports drinks. He points out that the American diet is usually deficient in magnesium and suggests that people engaged in strenuous sports activities supplement with the RDA (Recommended Daily Allowance) for magnesium (350 mg/day for men and 280 mg/day for women in the USA) provided they do not suffer from kidney failure.
Whang, Robert. Electrolyte and water metabolism in sports activities. Comprehensive Therapy, Vol. 24, January 1998, pp. 5-8