Question

During heavy exercise, we get cramps in the legs due to the accumulation of

• A. Carbon dioxide
• B. Lactic acid
• C. Alcohol
• D. water

Answer 1

The correct option is B

Lactic acid

The correct option is B.
Explanation of the correct option:

1. Respiration is the process of release of energy by breaking down food molecules(glucose) that are stored in the body cells.
2. There are two types of respiration: Aerobic respiration and anaerobic respiration.
3. The cellular respiration that takes place in absence of oxygen is known as anaerobic respiration.
4. During excessive physical exercise, muscle cells undergo anaerobic respiration to produce lactic acid and energy(ATP).
5. When the amount of lactic acid increases in muscle cells, the muscles become temporarily fatigued.
6. Anaerobic respiration in muscle cells follows the following equation :

C₆H₁₂O_{6 ⇢} C₂H₆O3 + Energy
(Glucose) (lactic acid) (ATP).

Final answer:
During heavy exercise, we get cramps in the legs due to the accumulation of lactic acid.