Magnesium loss in magnesium deficient subjects with and without physical exercise during prolonged hypokinesia.

OBJECTIVE To show the effect of hypokinesia (HK; diminished movement) on magnesium (Mg2+) loss in Mg2+ deficient subjects and the effect of physical exercise and on Mg2+ deficiency with and without physical exercise: Mg2+ balance, serum Mg2+ concentration and Mg2+ loss were measured. METHODS Studies were conducted on 30 healthy male volunteers during a pre-experimental period of 30 days and an experimental period of 364 days. They were divided equally into three-groups: unrestricted active control subjects (UACS), continuous hypokinetic subjects (CHKS) and periodic hypokinetic subjects (PHKS). The UACS group ran average distances of 9.3 +/- 1.2 km.day-l; the CHKS group walked average distances of 0.9 +/- 0.2 km.day-l; and the PHKS group walked and ran average distances of 0.9 +/- 0.2 km and 9.3 +/- 1.2 km.day-l for 5-and 2-days per week, respectively. RESULTS Mg2+ deficiency, serum Mg2+ level, fecal and urine Mg2+ loss increased (P < 0.05), in the PHKS and CHKS groups compared with their pre-experimental values and the values in the UACS group. However, serum Mg2+ concentration, urine and fecal Mg2+ loss and Mg2+ deficiency increased more (P < 0.05) in the PHKS group than in the CHKS group. CONCLUSIONS Mg2+ deficiency is more evident with than without physical exercise and Mg2+ loss is exacerbated more with higher than lower Mg2+ deficiency. This indicates that Mg2+ deficiency with and without physical exercise and Mg2+ loss with higher and lower Mg2+ deficiency is due to inability of the body to use Mg2+ and more so when physically healthy subjects are submitted to prolonged periodic than continuous hypokinesia.