Acute responses to exercise

• increased cardiac output


  more demand for oxygen
• increased blood pressure


  due to an increase in cardiac output
• vasodilation


  to allow greater blood flow to working muscles
• redistribution of blood flow


  blood flow redirects from the intestines, liver, and kidneys to the working muscles
• increased A-vO2 diff


  as exercise intensity increases, the muscles increase the amount of oxygen extracted from the blood
• decreased blood volume

  due to an increased intra-capillary pressure in contracting muscles
• increased venous return


  when muscles surrounded by veins contract, pressure is increased within the veins, pushing open the proximal valve and forcing blood towards the heart.