5. Cardio- Arterio-venous Oxygen Difference (A-VO2 Difference)

Question 1

What is it?

Answer 1

Is the difference between the oxygen content of the arterial blood arriving at the muscles and the venous blood leaving the muscles.

Question 2

During exercise

Answer 2

During exercise the arterioles-venous oxygen difference is high for all individuals. As exercise intensities increase, the muscles increase the amount of oxygen they extract from the blood, and this therefore results in further increases in a-vO2 diff. Consequently, at the alveoli more oxygen is taken in and more carbon dioxide removed

Question 3

Trained vs untrained performers

Answer 3

Training also increases the arterioles-venous oxygen difference as trained performers can extract a greater amount of oxygen from the blood.

The maximum a-vO2 diff is also usually greater in trained athletes than in untrained individuals. … With training the muscles also improve in their ability to extract oxygen from the blood and process the oxygen, possibly due to adaptations of the mitochondria and an increase in the muscle’s myoglobin content.