Muscle metabolic, enzymatic and transporter responses to a session of prolonged cycling

摘要: A single session of prolonged work was employed to investigate changes in selected metabolic, transporter and enzymatic properties muscle. Ten active but untrained volunteers (weight = 73.9 ± 4.2 kg) with a peak aerobic power \( \left( {\dot{V}{\text{O}}_{{2{\text{peak}}}} } \right) \) 2.95 0.27 l min−1, cycled for 2 h at 62 1.3% Tissue extraction from the vastus lateralis occurred prior (E1-Pre) following (E1-Post) exercise on 3 consecutive days recovery (R1, R2, R3). The resulted decreases (P < 0.05) ATP (−9.3%) creatine phosphate (−49%) increases lactate (+100%), calculated free ADP (+253%) AMP (+1,207%), all which recovered E1-Pre by R1. Glycogen concentration, depressed 75% E1-Post, did not recover until R3. Compared E1-Pre, cycling also activities cytochrome c oxidase, phosphorylase, hexokinase citrate synthase (CS) or 3-hydroxy-CoA dehydrogenase E1-Post. With exception CS, elevated R3, enzyme were different during recovery. For glucose (GLUT1, GLUT4) monocarboxylate (MCT1, MCT4) transporters, expression levels only observed GLUT1 R1 (+42%) R3 (+33%). It is concluded that metabolic stress produced reversed 1 day One potential upregulation citric acid cycle transport capabilities, adaptations are expressed variable durations.