EVERYDAY SCIENCE

Detailed explanation-1: -(sports) To feel the burning sensation arising in a muscle being intensely exercised; often used as an exhortation to extend oneself in physical exercise.

Detailed explanation-2: -This burning sensation is associated with a buildup of acid in the muscles during intense exercise, and lactic acid has long been thought to be the culprit in that acid buildup, known as acidosis. Lactic acid is a byproduct of anaerobic metabolism, in which the body produces energy without using oxygen.

Detailed explanation-3: -Lactic acid fermentation is the process by which our muscle cells deal with pyruvate during anaerobic respiration. This happens when we exercise too fast or hard because the oxygen supply can’t keep up with the need. That’s when our muscles switch from aerobic respiration to lactic acid fermentation.

Detailed explanation-4: -Correct answer: Lactic acid fermentation is the conversion of pyruvate to lactate, and occurs only under anaerobic conditions. Glycolysis always occurs under anaerobic conditions, and glucose needs to be broken down to fuel the sprinter.