Question

During exercise, the heart rate increases to

• A. Supply more lactic acid to the muscles for anaerobic respiration
• B. Supply more oxygen and glucose to the respiring cells
• C. Keep up with the pulse rate
• D. Keep down the pulse rate

Answer 1

The correct option is B Supply more oxygen and glucose to the respiring cells

During heavy exercise, fast running, cycling, walking for many hours or heavy weight lifting, the demand for energy is high but the supply of oxygen to produce the energy is limited. So, the heart rate increases to supply more oxygen and glucose to the respiring cells. Anaerobic respiration takes places in the muscle cells to fulfil the demand of energy.