The impact of physical exercise on calcium balance in healthy subjects during prolonged hypokinesia

ObjectiveTo determine whether during hypokinesia (diminished movement) periodic physical exercise affects calcium (Ca2+) balance and Ca2+ loss.MethodsStudies were conducted on 30 physically healthy male volunteers during the preexperimental period of 30 days and the experimental period of 364 days. They were equally divided into three groups: active control subjects (ACS), hypokinetic subjects (HKS), and periodic training subjects (PTS). The ACS group ran an average distance of 9.3 ± 1.2 km/d; the HKS group walked an average distance of 1.3 ± 0.2 km/d; and PTS group walked and ran average distances of 1.3 ± 0.2 km/d and 9.2 ± 1.2 km/d for 5 and 2 days per week, respectively.ResultsSerum Ca2+ level, fecal and urine Ca2+ loss, and Ca2+ imbalance increased (P < 0.05) in the PTS and HKS groups compared with their preexperimental levels and the values in their respective ACS group. The serum Ca2+ concentration, urine and fecal Ca2+ loss, and Ca2+ imbalance increased more (P < 0.05) in the PTS group than in the HKS group.ConclusionDuring hypokinesia, Ca2+ imbalance is more evident with than without physical exercise and Ca2+ loss is exacerbated more with higher than lower Ca2+ imbalance.