Les déficits en magnésium et le sport

Abstract

Cet article aborde les relations entre le magnésium et le sport, à savoir: Les besoins, les effets physiologiques, la prévalence des déficits en magnésium, puis les causes de ces déficits, les conséquences pathologiques qui en découlent dans la pratique sportive et enfin les moyens de s'en prémunir, à savoir la réforme de l'alimentation et la supplémentation, dont plusieurs études ont montré l'intérêt chez les athlètes. This paper deals with the relationship magnesium and sports. In the first part, the physiology of this cation is reviewed. Its distribution (mainly inside the cellular compartment), the theoretical value of the biological indices (more or less reliable, as indicators of magnesium status), the requirements (which are still controversal and certainly underestimated for sportsmen), Mg functions in energy supply during physical activities, and current biological investigations are in turn developed. The second part is more specifically concerned with the high frequency of Mg deficiencies among sportmen, as the most recent findings indicate. This high incidence, and the remaining biological abnormalities that occur, entail pronounced and severe deficiencies among sportsmen. Thus, many physiological disorders appear, one of them being particularly well documented, i.e. the decrease of O2 delivery to the working muscles. Both animal and humans trials as well as clinical observations substantiate this assumption. Hence, physical capability to sustain a strenuous and/or a prolonged effort is hampered. Reasons are examined: increased needs, high sweat output rates, stress-induced response to the effort (in part mediated via FFA release), and, foremost, unbalanced diet, failing to fulfill the sportmens' requirements, are often evoked. The last part deals with both expectable short-term and long-term solutions. One can advocate progressive and long-lasting dietary changes, leading to a better balance and a higher Mg nutritional density, with less impairing cooking habits (preserving less mineral content in the foodstuffs), and rich-water consumption; (their incremental effect towards Mg status is already proven in rodents). Mg supply, by Mg salts, is another expectable measure to be taken. Many improvements have already been observed in sportsmen, confirmed by better blood values and performances, as a consequence of this supply, even over a very short period. From these data, one should give more attention to sportsmens' Mg status, from medical practitioners, and also from coaches and, finally, the concerned athletes.