Effect of short-term training on GLUT-4 mRNA and protein expression in human skeletal muscle

Abstract

Six untrained, male subjects (23 ± 1 years old, 84 ± 5 kg, ̇VO2peak = 3.7 ± 0.81 min-1) exercised for 60 min at 75 ± 1% ̇VO2peak on 7 consecutive days. Muscle samples were obtained before the start of cycle exercise training and 24 h after the first and seventh exercise sessions and analysed for citrate synthase activity, glycogen and glucose transporter 4 (GLUT-4) mRNA and protein expression. Exercise training increased (P < 0.05) citrate synthase by ∼20% and muscle glycogen concentration by ∼40%. GLUT-4 mRNA levels 24 h after the first and seventh exercise sessions were similar to those measured before the start of exercise training. In contrast, GLUT-4 protein expression was increased aft..