The effects of magnesium supplementation on blood parameters were studied during a period of 4 wk in adult tae-kwondo athletes at rest and exhaustion. Thirty healthy subjects of ages ranging in age from 18 to 22 yr were included in the study. The subjects were separated into three groups, as follows: Group 1 consisted of subjects who did not train receiving 10 mg/kg/d magnesium. Group 2 included subjects equally supplemented with magnesium and exercising 90120 min/d for 5 d/wk. Group 3 were subject to the same exercise regime but did not receive magnesium supplements. The leukocyte count (WBC) was significantly higher in groups 1 and 2 than in the subjects who did not receive any supplements (p < 0.05). There were no significant differences in the WBC of the two groups under magnesium supplementation. The erythrocyte, hemoglobin, and trombocyte levels were significantly increased in all groups (p < 0.05), but the hematocrit levels did not show any differences between the groups although they were increased after supplementation and exercise. These results suggest that magnesium supplementation positively influences the performance of training athletes by increasing erythrocyte and hemoglobin levels.
The most recent US surveys on nutritional intake in our diet has found that the average intake of magnesium for men is at 75% of the RDA, and for women at 71 % of the RDA. Based on this data, 50% of the US populace has a magnesium intake that is at a level that puts us into a marginal deficiency status, at best. At this level, a number of important physiological functions are compromised. It is known that magnesium is a mineral of critical importance to the production of energy and muscle strength. Research has shown that the performance of exercise and sport performance causes an increased loss of magnesium that is proportional to the length and intensity level of that exercise or sport performance. The danger for a variety of adverse health consequences is real. Studies have shown a variety of these consequences. Cardiac problems, epileptic-like convulsions, immunosuppression, oxidative damage, and chronic fatigue have been seen in athletes due to a lack of proper magnesium intake, combined with exercise -induced magnesium loss. With this background, the consideration of employing a magnesium supplementation program by people who are involved with exercise is understandable. The development of an activity based RDA, as suggested by Dr. H.C. Lukaski (USDA) is a very good idea. The problem remains that the individual really doesn’t know where their dietary magnesium intake stands. With the range of safety seen for magnesium, in terms of daily intake, a supplement program that provides the RDA of magnesium would seem to be a good start for any person engaged in strenuous exercise or athletic performance.