Glucose utilization and ATP production. A. Degradation of exogenous and endogenous glucose (glycogenolysis) by glycolysis and oxidative phosphorylation. B. Steady state rates of aerobic and anaerobic ATP production from glucose utilization derived from exogenous glucose and glycogenolysis. Data are expressed as boxplots. ∗significant difference between endogenous and exogenous glucose. p < 0.05 (unpaired t-test).