Question

Why does continuous running cause cramps to a person’s muscles?

Hint:

Cramps → “{Lactic Acid Buildup}” due to lack of oxygen.

Answer 1

Step 1: Normal condition
Normally, our muscles obtain energy by breaking down glucose in the presence of oxygen. This is called aerobic respiration, which produces carbon dioxide, water, and a large amount of energy (38 ATP per glucose). \[ Glucose + O_{2} \;\; \longrightarrow \;\; CO_{2} + H_{2}O + Energy \]
Step 2: During continuous running
When a person runs continuously, the demand for energy in the muscles increases rapidly. The oxygen supply through blood becomes insufficient.

Step 3: Anaerobic respiration in muscles
In the absence of sufficient oxygen, muscles switch to anaerobic respiration, where glucose breaks down incompletely to form lactic acid and less energy. \[ Glucose \;\; \longrightarrow \;\; Lactic \; Acid + Energy \]
Step 4: Reason for cramps
The accumulation of lactic acid in muscles causes stiffness and pain, which we feel as cramps. After rest, oxygen supply is restored, lactic acid is broken down, and cramps disappear.
Final Answer:
Continuous running causes cramps due to the accumulation of lactic acid in muscles as a result of anaerobic respiration.