Multiple choice

Why does heavy exercise cause muscle cramps?

  1. Due to formation of lactic acid.

  2. Due to evolution of high concentration of CO2 .

  3. Due to formation of ethanol.

  4. Due to complete absence of oxygen in muscles.

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During heavy exercise, muscles require more oxygen than can be supplied, leading to anaerobic respiration. This process produces lactic acid as a byproduct, which accumulates in muscle tissue and causes cramps. The other options are incorrect because CO2 is a normal byproduct, ethanol is produced in yeast fermentation, and muscles never have complete absence of oxygen (that would cause tissue death, not cramps).