Sweating naturally increases the concentration of salt in the body. Salt tablets take water from the cells, causing weak muscles. They also increase potassium losses. Potassium is important to help regulate muscle activity. Salt added to beverages during endurance events may be helpful.
Iron carries oxygen and is another important mineral for athletes.
Female athletes and athletes between 13 and 19 years old may have inadequate supplies of iron. Female athletes who train heavily have a high incidence of amenorrhea and thus conserve iron stores. Iron supplements may be prescribed by a physician if laboratory tests indicate an iron deficiency. Excess iron can cause constipation. To avoid this problem, eat fruits, vegetables, whole grain breads and cereals.