Changes on plasmatic and erythrocytic magnesium levels after high-intensity exercises in men

The aim of this paper was investigate the effects of high-intensity exercise on plasmatic and erythrocytic Mg levels in men. Twelve normal male volunteers participated in this study. The tests were performed on a cycle-ergometer (Monark). The exercise programs consisted of: 1) triangular progressive test (TPT); 2) interval endurance test (IET), of 45 min duration; and 3) maximal subtained test (MST), consisting of a maximal level, at 100% of MTP, for at least 7 min. The percent change in plasma volume (%PV) after exercise was calculated. Magnesium levels in plasma and erythrocytes were measured by atomic absorption spectrophotometry. No significant differences in the absolute Mg concentration of plasma were noted for the three maximal exercises. The percentage increase in plasma Mg concentrations was about 5-7%; however, percent decrease of PV was more important (13-16%). Erythrocytic Mg levels were increased after all maximal exercises (TPT, IET, and MST), although absolute Mg concentrations were not significantly different.