Cardiovascular endurance is the most important aspect of fitness. It is basically how strong your heart is, which can potentially add years to your life. The heart is the most important muscle in the human body and if it is kept healthy then you can avoid numerous health problems. Another reason that cardiovascular endurance is important is because your heart controls the oxygen flow to all your muscles – meaning cardiovascular health has a direct impact on your performance, both endurance and strength wise.
The reason your cardio performance can be improved is because the heart is a muscle, and like all other muscles in the body if you keep working it it will adapt to the workload given. This allows us to have direct control of how healthy one of the most important systems in our body is. But keep in mind there are other factors that effect heart health, such as cholesteral, and blood pressure. Eating right and exercising will ensure that your heart becomes, and remains, healthy throughout your life.