Question

The sensation of fatigue in the muscles after prolonged strenuous physical work, is caused by:

• A. A decrease in the supply of oxygen
• B. Minor wear and tear of muscle fibers
• C. The depletion of glucose
• D. The accumulation of lactic acid

Answer 1

The correct option is D The accumulation of lactic acid

During intense exercise, circulatory system cannot keep up with the oxygen demand in the muscles. To maintain with a steady supply of energy, muscles shift from aerobic to anaerobic respiration.
The sensation of fatigue in the muscle after prolonged strenuous physical work is caused due to accumulation of lactic acid, which is formed because of anaerobic respiration in the absence of oxygen.