Lactic Acid System (Anaerobic Glycolysis) – Lecture Notes

Vocabulary flashcards covering fuel sources, process characteristics, fatigue mechanisms, recovery, and key terms related to the lactic acid (anaerobic glycolysis) energy system.

Lactic Acid System (Anaerobic Glycolysis)

Energy pathway that resynthesises ATP without oxygen by breaking down glucose/glycogen, dominant from ~10 s to 75 s of maximal effort.

Glycogen

Stored form of glucose in liver and muscles; primary fuel for anaerobic glycolysis once CP is exhausted.

Glycolysis

Series of rapid chemical reactions that convert glucose to pyruvate (and ultimately lactate) to produce ATP in the absence of oxygen.

ATP Resynthesis Efficiency (Anaerobic)

Fast but low-yield process that produces only 2 ATP per glucose molecule.

Operational Duration

Begins contributing after ~5 s, reaches full capacity at 10 s, powers maximal activity up to 75 s (up to ~3 min at >85 % sub-maximal effort).

Muscle Acidosis

Drop in muscle pH caused by accumulating hydrogen ions during anaerobic glycolysis, leading to fatigue and reduced contractile force.

Lactate

Compound formed when pyruvate binds with hydrogen; helps buffer acidity and is later transported to the liver for metabolism.

Primary Cause of Fatigue (Anaerobic Glycolysis)

Accumulation of hydrogen ions (muscle acidosis) rather than lactate itself.

Creatine Phosphate (CP)

High-energy compound that fuels ATP-PC system for the first 10-12 s; depletion triggers reliance on anaerobic glycolysis.

Lactate Removal

Transport of lactate to the liver where it is converted back to glycogen; complete clearance takes ~30 min–2 h.

ATP-PC System

Immediate energy system preceding anaerobic glycolysis, dominant for very short (0–10 s) explosive efforts.

Active Recovery

Low-intensity movement post-exercise that maintains blood flow, speeds lactate clearance, and allows repeat high-intensity efforts after ~2–5 min.