Abstract

It is well known that serum magnesium decreases during exercise. According to the literature this decrease results from an intercompartmental shift. However, the nature of the magnesium curve during different exercise intensities and the true recovery potential is still unknown. In order to elucidate these certainties, the magnesium responses were studied during different intensitiesof treadmill exercise. Venous blood was sampled intermittently and analysed for Mg++ concentration, haematocrit and haemoglobin. The total circulating serum Mg++ was calculated from haemoglobin and haematocrit values. The resultsindicate that exercise intensity is related to the rate of change in total circulating serum Mg++ and not to serum Mg++ concentration. Following three hours of exercise, 95 of the pre-exercise serum Mg++ concentration was attained within three hours of rest, indicating that the decrease in serum magnesium concentration was the result of an intercompartmental shift of Mg++. Verf.-Referat