Anaerobic respiration in muscles during exercise

• During vigorous exercise, the muscles do not receive enough oxygen
• The muscle cells therefore respire anaerobically
• Only glycolysis takes place
• Pyruvic acid is formed
• Glucose is broken down
• Only a small amount of energy is released
• Pyruvic acid is converted into lactic acid, which is released in the muscle cells
• Lactic acid fermentation is the process of breaking down glucose to produce lactic acid
• Lactic acid is a toxin that leads to muscle stiffness and muscle pain
• Oxygen is needed to convert the lactic acid back to pyruvic acid
• Moderate exercise with deep breathing is needed to get rid of muscle stiffness
• If there is sufficient oxygen, aerobic respiration takes place and pyruvic acid enters the Krebs cycle