Cardiovascular Endurance -
The efficiency with which you get oxygen to your working muscles and remove the metabolic wastes that are building up there. (The hearts ability to pump a large volume of blood to and from the working muscles for and extended period of time.)
Ways to measure Cardiovascular Efficiency:
1) heart rate (decrease in resting heart rate)
2) stroke volume (how much blood you pump out of your heart with each beat)
3) ejection fraction of the left ventricle (the percentage of blood in the left ventricle of your heart muscle that is pushed out with each beat)
4) V02max - increase in maximum oxygen uptake ability (how much oxygen your muscles use during exercise)