A-Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance--Part 13.

摘要

This issue begins with a brief article on electrolytes, now popularly offered to athletes in supplement form, as a discrete product or as an ingredient of sports drinks. Two herbs are also discussed: echinacea and ephedra. Both plants are popular supplements of athletes worldwide, but the similarities end there.Electrolytes are negatively (anions) or positively (cations) charged substances that, when in solution, conduct an electric current. Major physiological electrolytes include Na+, K+, Cl" and HCO3~, while other electrolytes such as Ca~(2+), Mg~(2+) and trace elements are also found in the body in significant amounts. Na~+, K~+; Cl" and HCO_3~ are primarily responsible for normal water distribution and homeostasis throughout the body via their effect on osmotic pressure. These major electrolytes also play an essential role in regulating heart and muscle function, maintaining pH and a number of other important biochemical reactions.