Cardiovascular endurance or fitness is simply indicative of how effective your heart and lungs send oxygen-rich blood to your muscles for energy.  The more efficiently this process runs the longer your body can sustain movement.  Obviously then, to improve cardiovascular endurance you must exercise.  However, instead of trying to go run 15 miles a day, there are more efficient ways to improve your cardio.

First and foremost, the correct diet is essential to improving your endurance.  Make sure you are ingesting lots of greens, as well as fruits.  It is still great to throw down a steak now and again, but stay away from fatty meats.  Chicken breast and salmon are among the healthiest types of meats around.  Be sure to have no nutrient deficiencies from lack of vitamin and mineral intake.

Second, it is not necessary to run miles and miles in order to improve cardio, though this does work.  Instead, work on combining many types of exercise.  Not only will this improve cardio, it will also save wear on your joints and body as a whole.  For example, incorporate superset lifting, cycling, swimming, and interval training into your routine.

Lastly, some supplements will naturally increase cardio ability.  Any amino acids that increase blood flow by way of increasing your body’s production of NO2, nitric oxide.  For instance, l-arginine is an amino acid known to do this.  Other supplements like beetroot juice, have shown to increase NO2 production as well.