Final answer:
During exercise, the whole body meets the increased VO2 demand of muscles by increasing the heart rate and cardiac output, and by increasing the amount of oxygen carried by red blood cells.
Step-by-step explanation:
The whole body meets the increased VO2 demand of muscles during exercise by increasing the heart rate and cardiac output, which improves the delivery of oxygen to the muscles. Additionally, the amount of oxygen carried by red blood cells increases, allowing more oxygen to be delivered to the muscles.