A student runs 5 km each afternoon at a slow, leisurely pace. One day, she runs 2km as fast as she can. Afterward, she is winded and feels pain in her chest and leg muscles. She thought she was in great shape. What is she experiencing?

Cellular respiration

Explanation:

Cellular respiration is defined as a ATP generating process in which organic molecule is oxidized and inorganic molecule is final electron acceptorPain experienced in leg muscles is the result of formation of lactic acid in muscle cellsUnder low oxygen, NADH cannot be reoxidized to NAD+ but NAD+ is required as an electron acceptor to continue glycolysis In lactic acid fermentation pyruvate is the final electron acceptor and converted in lactate Reaction catalyzed by lactate dehydrogenase The pain in her chest is caused from the lack of oxygen she received while running so her chest starts to heavily breathe so that the lungs can receive as much oxygen possible

Centration is the correct answer