During a marathon, a runner experiences muscle cramps. Which of the following physiological changes is primarily responsible for this condition?
Q1. During a marathon, a runner experiences muscle cramps. Which of the following physiological changes is primarily responsible for this condition?
Answer: Overload of sodium ions within muscle cells
Explanation: Dehydration and sodium imbalance lead to muscle cramps. Incorrect options: Depletion of glycogen stores causes fatigue, not cramps; anaerobic respiration produces lactate, not cramps; decreased lactate production is beneficial, not harmful.