Cardiovascular system

• Vasoconstriction


  Narrowing of blood vessels
• Vasodilation


  Widening of blood vessels
• Arterio-venous oxygen difference (A-VO₂ diff)

  Difference between the oxygen content of the arterial blood at the muscles and the venous blood leaving the muscles
• The cardiovascular system is the body's transport system. It includes the heart and the blood vessels.
• During exercise, an efficient cardiovascular system is extremely important as the heart works to pump blood through the various
• At rest, the arterio-venous difference is low as not much oxygen is required by the muscles. But during exercise, much more oxygen is needed from the blood for the muscles so the arterio-venous difference is high.
• The increase in arterio-venous difference affects the body to change so more oxygen is taken in and more carbon dioxide is removed. Respiration also increases the arterio-venous difference as fitter performers can extract a greater amount of oxygen from the blood at rest and active.
• Measurements


  • Heart rate
  • Stroke volume
  • Systolic pressure