ABSTRACT
This chapter describes research results of mineral supplementation on exercise performance, excluding the electrolytes sodium, potassium, and chloride. The only nonelectrolyte minerals studied in any detail are calcium, magnesium, zinc, iron, selenium, chromium and phosphorus (as phosphate). The only trace minerals with a theoretical rationale for use are zinc (to correct possible deficiencies), rubidium and cesium (to change intracellular pH), chromium (to affect carbohydrate and amino acid metabolism via effects on insulin), selenium (as an antioxidant), and vanadium (for insulin receptor effects). Magnesium losses in sweat can become significant if sweating is profuse. Iron supplementation to anemic persons (including athletes) has improved hemoglobin concentration, red blood cell count, hematocrit, VO2 max, maximal work times, heart rate responses, and performance times. The primary role of selenium is to provide activity for glutathione peroxidase, a major cellular antioxidant. The essential qualities of chromium relate to its function as the Glucose Tolerance Factor and its involvement with insulin metabolism.
