Cardiovascular endurance, also known as aerobic fitness, is a measure of how well the heart, lungs, and blood vessels can transport oxygen to the muscles during exercise. It is a health-related component of physical fitness that is brought about by sustained physical activity. Strong cardiovascular endurance allows the body to move blood efficiently, providing more oxygen to muscle cells, which serves as an energy source to fuel the cells in tissues and muscles. Improving cardiovascular endurance can make it easier to perform exercises or movements for extended periods of time.

Cardiovascular endurance has many benefits, including improving cholesterol and blood pressure levels, reducing the risk of many diseases such as heart and blood vessel conditions, and helping to live longer. A study published in the American Journal of Epidemiology found that higher levels of cardiovascular fitness were associated with a lower risk of mortality from all causes, including cardiovascular disease and cancer.

To improve cardiovascular endurance, one can do activities that increase the amount of oxygen breathed in. One can start with 10 to 15 minutes of cardiovascular endurance exercises a day and challenge the body a little at a time by adding a few minutes each day. Adults should get at least 150 minutes of exercise every week. Examples of cardiovascular endurance activities include swimming, riding a bike, running, and brisk walking. High-intensity interval training (HIIT) is also an effective way to improve cardiovascular endurance.

Cardiovascular endurance is measured by looking at the maximum uptake of oxygen (VO2 max) and how it is used during intense exercise. The more oxygen one uses and the more effectively it is being used, the better the cardiovascular endurance.