Excess post-exercise oxygen consumption is the extra amount of oxygen consumed after the completion of exercise and before respiration returns to resting levels. This extra oxygen is used to restore muscle fibers to their pre-exercise state by doing all of the following EXCEPT:

Question

Excess post-exercise oxygen consumption is the extra amount of oxygen consumed after the completion of exercise and before respiration returns to resting levels.  This extra oxygen is used to restore muscle fibers to their pre-exercise state by doing all of the following EXCEPT:

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11ecba2d_0fe6_531d_a3bf_5ba34233cb22_MD0008_00 Excess post-exercise oxygen consumption (EPOC), or oxygen debt, represents the amount of oxygen necessary to bring the muscle back to its resting state. EPOC is equivalent to the difference between the amount of oxygen actually required for the physical activity and the total amount of oxygen used. Muscles require ATP to contract. Aerobic respiration uses oxygen to generate more molecules of ATP per metabolized glucose molecule than anaerobic glycolysis. Consequently, aerobic respiration is the primary source of ATP in muscle fibers during vigorous, long-term exercise. However, when oxygen delivery from the blood is insufficient (eg, during rapid, high-intensity exercise) and the demand for contraction exceeds the speed at which aerobic respiration can generate ATP, muscle fibers compensate by: utilizing ATP that is stored in the muscle fiber breaking down creatine phosphate, a high-energy molecule stored by muscle cells during periods of rest, to generate ATP generating ATP via anaerobic glycolysis, which yields 2 pyruvate molecules and 2 net ATP molecules per glucose molecule. In the absence of oxygen, the 2 pyruvate molecules are converted to lactic acid. continuing aerobic respiration using oxygen that is bound to myoglobin, a red-pigmented oxygen storage molecule Once motor neuron input ceases, the fiber relaxes and begins replenishing these back-up energy reserves to prepare for the next burst of activity. Consequently, oxygen intake (deep breathing) remains elevated even after physical activity has stopped because oxygen is required to resynthesize ATP and creatine phosphate (Choice A) and restock myoglobin (Choice C). In addition, glycogen stores broken down during exercise must be replenished. In a process known as the Cori cycle, lactic acid produced during anaerobic respiration is transported to the liver, where ATP is used to metabolize lactic acid back to glucose. Glucose is transported back to muscle and stored as glycogen (Choice D) or metabolized to pyruvate. (Choice B) During rest or relaxation, calcium is sequestered into (not released from) the sarcoplasmic reticulum. Educational objective: Oxygen intake remains elevated after exercise due to the increased demand in muscle cells for oxygen to replenish ATP, creatine phosphate, and glycogen stores and restock myoglobin with oxygen. The amount of additional oxygen consumed is called the excess post-exercise oxygen consumption, or oxygen debt.

Excess Post-Exercise Oxygen Consumption Is the Extra Amount of Oxygen