Resistance Exercise Increases the Capacity of Heme Biosynthesis More Than Aerobic Exercise in Rats.

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.