Question

Explain why the body must use anaerobic respiration (fermentation) instead of cellular respiration during intense physical activity.

Answer 1

Human body can generate energy using both aerobic and anaerobic respiration. The amount of energy generated by aerobic respiration is more than that of anaerobic respiration. So generally muscle cells generate energy by aerobic respiration. During intense physical activity the muscle cells fall short of oxygen but have to work. Thus, body needs anaerobic respiration to continue the muscle activity during intense physical activity. Anaerobic respiration give rise to lactic acid formation in muscle cells which causes cramps in muscles.