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Abstract. Magnesium is a cofactor involved in many enzymatic systems, being necessary for protein synthesis, functioning of nervous and muscular systems, regulation of blood pressure and glycaemia, bone metabolism. A low dietary intake of magnesium is very common in general population. Additionally, there are categories of population that are even more predisposed to hypomagnesaemia. Top athletes represent a population category predisposed to magnesium deficiency due to increased urinary and sudorific losses, and in case of heavyweight disciplines, due to a decreased dietary intake. Many studies supported the role of magnesium in athletic performance and showed that magnesium increased the physical endurance and improved the force indices and muscle metabolism in athletes that had a rich diet in magnesium or received magnesium supplements. It is still uncertain whether the positive effects of magnesium supplementation in athletic performance are due to pharmacological actions of magnesium itself or to the reversal of a pre-existing magnesium deficiency. Therefore, the purpose of this article is briefly review of Magnesium importance in human health and athletics performance, various hypotheses that may explain magnesium's physiologic action mechanisms but also possible pathways for magnesium deficiency's correction.
Key words: magnesium, athlete, deficiency, supplementation.
Some basics of Magnesium
Magnesium is the second most abundant mineral in cells after potassium, but the two ounces or so found in the typical human body is present not as metal but as magnesium ions (positively-charged magnesium atoms found either in solution or complexed with other tissues, such as bone). Roughly one quarter of this magnesium is found in muscle tissue and three-fifths in bone; but less than 1% of it is found in blood serum, although that is used as the commonest indicator of magnesium status.
This blood serum magnesium can be further subdivided into free ionic, complex-bound and protein-bound portions, but it's the ionic portion that's considered most important in measuring magnesium status, because it is physiologically active.
The importance of magnesium as an essential nutrient has been emphasised as early as 1932 by Kruse et al., who induced an acute magnesium deficiency in rats by limiting the dietary intake of this element to 0.09mEq/kilogram. Hypo-magnesaemia produced hyperemia, neuromuscular progressive irritability that eventually precipitated fatal convulsions in these animals (1).
The role of Magnesium in the body