Abstract
To evaluate the effects of voluntary resistance exercise and aerobic exercise on iron status in rats fed an iron-deficient diet (5mg Fe/kg, ID) or rats fed a control diet (35mg Fe/kg, CN), we trained female Wistar rats for 3 weeks to climb a wire-mesh tower (∅20cm×200cm, CLIMB) and to swim in a plastic pool (∅50cm×50cm, SWIM). These animals were compared with sedentary (SED) rats. After the experimental period, the blood hemoglobin concentration, hematocrit, plasma iron, and transferrin saturation were significantly lower (p<0.05) in the ID rats than in the CN rats; as was the content in the liver, spleen, heart, kidney, skeletal muscles, and carcass (p<0.05). The activity of δ-aminolevulinic acid dehydratase, the marker enzyme for heme biosynthesis, in bone marrow was significantly higher (p<0.05) in the CLIMB group than in the SWIM group. These results suggest that resistance exercise increases heme biosynthesis more than aerobic exercise but that neither exercise improved severe iron deficiencies.