After several miles of running and sprinting in intervals, the runner's muscles ache and feel fatigued. Which is the best explanation for what has occurred?

The runner's muscles have accumulated lactic acid.

The runner's body has failed to perform cellular respiration.

The runner's cells are relying completely on aerobic respiration.

The runner's muscles have accumulated carbon dioxide.

"The runner's muscles have accumulated lactic acid" is the best explanation for what has occurred.

Answer: Option A

Explanation:

Lactic acid is generated in one's muscles and forms throughout strenuous exercise. It can contribute to muscles that are uncomfortable and fatigued. Muscle cramping is usually harmless due to workout and is not a cause of much worry, but it can impact your workouts by causing stress.

Red blood cells and muscle cells are developed mainly in Lactic acid. This develops when the body breaks down carbohydrates when the oxygen levels are low to use for energy. Sour milk products such as laban, yogurt, koumiss and few cottage cheeses are lactic acid rich.

The runner's muscles have accumulated lactic acid.

Explanation:

The muscle ache is due to the accumulation of acid, a condition k/a acidosis.

The lactic acid is formed when due to the absence of oxygen during strenuous workout, anaerobic respiration takes place in which glucose beakdown to lactic acid.

There is lactic acid formed along with carbon dioxide and only 2 molecules of ATP which is very less than actual aerobic cellular respiration releases and causes muscle fatigue.

The lactate or lactic acid will get mixed up in bloodstream very fast hence cannot be used as an energy source.