Chronic antiorthostatic sleeping (CAS) reduces gravity effects and creates periodic fluid redistribution (PFR) that in turn helps to recover electrolyte capabilities lost because of impaired electrolyte deposition. It was hypothesized that CAS could restore muscle magnesium (Mg²⁺) deficiency during diminished muscular activity (Hypokinesia; HK). We therefore studied the clinical benefits for muscle Mg²⁺ from CAS during HK. Studies were conducted on 40 male healthy volunteers. They were equally divided into four groups: antiorthostatic sleeping control subjects (ASCS), antiorthostatic sleeping hypokinetic subjects (ASHS), active control subjects (ACS) and hypokinetic subjects (HKS). Muscle Mg²⁺, plasma Mg²⁺ and Mg²⁺ in urine and feces were measured during pre-experimental and experimental period of 390 and 364-days, respectively. Muscle Mg²⁺ increases (p < 0.05) and plasma Mg²⁺and the Mg²⁺ loss via urine and feces reduce (p < 0.05) in the ASHS group compared to the HKS group. Without CAS muscle Mg²⁺ decreases (p < 0.05) and plasma Mg²⁺ and the Mg²⁺ loss via urine and feces increase (p < 0.05) in the HKS group compared to the ASCS group, the ASHS group and ACS group and the values at the pre-experimental period. In the ASCS group muscle Mg²⁺ did not increase and plasma Mg²⁺ and the Mg²⁺ loss via urine and feces did not decrease as in the ASHS group and they did not change compared to ACS group. Muscle Mg²⁺, plasma Mg²⁺ and the Mg²⁺ loss via urine and feces did not change in the ACS group compared to the pre-experimental period values and the ASCS group that showed higher muscle Mg²⁺ and lower plasma Mg²⁺ and Mg²⁺ loss via urine and feces. The current study shows muscle Mg²⁺repletion as a result of CAS, suggesting a potential clinical treatment for muscle Mg²⁺deficiency during HK using CAS, through chronically applied PFR and reduced gravity effects.