Anaerobic Glycolysis: What Food Source Fuels It?

Glucose is the sole substrate that can enter anaerobic glycolysis directly.

Process

1. Glucose → (glycolysis) → 2 pyruvate + 2 ATP (net) + 2 NADH.
2. In absence of O₂, pyruvate → lactate (via lactate dehydrogenase), regenerating NAD⁺ for glycolysis to continue.
3. Yield: 2 ATP/glucose (vs. ~30–32 ATP via aerobic respiration).

Fuel Sources

• Dietary carbohydrates → glucose.
• Glycogenolysis (liver/muscle glycogen → glucose-1-P → glucose-6-P).
• Gluconeogenesis (from lactate, glycerol, amino acids) — minor during acute anaerobiosis.

Fatty acids and amino acids cannot be metabolized anaerobically; they require mitochondrial β-oxidation and TCA cycle (O₂-dependent).