Aerobic exercise includes activities such as low-to-moderate-intensity running, cycling, and swimming. These exercises are described as aerobic because they are fueled by aerobic metabolism, which means oxygen is used to make energy. The capacity to deliver oxygen to muscles via the cardiorespiratory system (the lungs, heart, and blood vessels) and the ability to produce energy (adenosine triphosphate, or ATP) using oxygen are important components of aerobic exercise performance.
While aerobic exercise performance determines success in endurance sports, it is also an important aspect of other sports that include an endurance component (e.g., soccer and basketball) and is closely tied to cardiovascular health.