Fig. 3.
The rate of ATP synthesis through anaerobic glycolysis (ATPgly, A), oxidative phosphorylation (ATPox, B), and the creatine kinase reaction (ATPCK, D) with respect to time during supramaximal plantar flexion exercise. The time course of PME (C) illustrates the glycogenolytic flux that has not passed through the glycolytic pathway. Relative contribution of the anaerobic glycolysis, oxidative phosphorylation, and the creatine kinase reaction to total ATP synthesis during exercise (E). Values are presented as means ± SE. None of the ATP synthesis rates were significantly different between the young and old (P > 0.05). *First data point that is significantly greater than 0 (glycolysis) or baseline (PME).