Question

Lactic acid accumulation leads to

• A. Muscle fatigue
• B. Kidney fatigue
• C. Liver fatigue
• D. All of these

Answer 1

Answer: (A)

Muscle fatigue

During strenuous exercise, metabolism of the body is relatively high which requires an enormous supply of energy. To maintain a steady supply of energy, muscles shift from aerobic metabolism, which requires oxygen, to anaerobic metabolism, which does not. Muscles can break down carbohydrates anaerobically to provide energy, resulting in a compound called pyruvate. When oxygen is available, pyruvate can be further broken down aerobically to provide more energy. But when sufficient oxygen is not available, pyruvate is converted into lactic acid. Lactic acid is rapidly broken down into a compound called lactate, resulting in the release of hydrogen ions. The body can clear lactate by metabolizing it for energy, but when lactate production exceeds the clearance rate, it accumulates in the muscles and bloodstream. While rising levels of lactate are associated with tired muscles, lactate does not actually cause fatigue. Rather, it is the increased acidity in the tissues, due to the buildup of hydrogen ions, that contributes to the sensation of fatigue. Lactic acid accumulation does not lead to kidney fatigue or liver fatigue.

So, the correct answer is option A.