In the sport world it is common to think that a dietary or pharmaceutical supplement with minerals can improve the physical performance or at least can help to keep this performance level, contributing at the same time to muscular endurance. This idea is based on several facts:
It is thought that athletes have special higher mineral needs than sedentary people, for which the basic mineral requirements have been establised.
Athletes consume diets with an inadequate amount of trace elements.
During exercise the elimination of these elements are higher than during leisurely activities.
Their uses by physiological processes are increasing.
Trace elements are very important since a partial deficit of them has a direct effect on physical performance and endurance. In extreme cases, it could produce pathological situations related with muscular tiredness. Therefore, the knowledge of mineral functions by organism structure and by physiological processes is essential to understand on the one side how minerals participate in biological processes and on the other one which is their relation with health and illness. During exercise and under a functional view point, the importance of some salts is mainly due to their electrolytes. These electrolytes have a function by nerve transmission in muscle and therefore by muscular contractibility.
In fact, the minerals which have a muscular function are positive ions: Sodium (Na+), Potassium (K+), Calcium (Ca++) and Magnesium (Mg++). K+, together with Na+, Ca++ and Mg++, has a main function by nerve and muscular transmission. It is well known that extra cellular concentration of Mg++ is very important to maintain electrical potential of nerve and muscular membranes as well as to transmit impulses along the mioneural unions (nerve-muscle). Muscular tiredness and other early symptoms of Magnesium deficit are related to low Magnesium concentrations in muscle and are not detected in serum (blood serum). Ca++ is essential during exercise since it takes part in stimulation-contraction processes in muscles. Finally, Sodium contributes decisively to maintain extra cellular volume and stimulates carbohydrate and water absorption at intestine level in order to replace muscular glucogen depots.
