Number one of the five components of physical fitness is the cardio/respiratory element. This component looks at the capacity and the capability of the lungs and the heart. Two major organs of the body, the lungs and heart need to work in harmony to deliver the oxygen and other nutrients to the cells throughout your body. The lungs are responsible for adding oxygen to the blood and removing carbon dioxide, while the heart is responsible for pushing that blood throughout the body. From the point of view of the five components of physical fitness, cardio/respiratory exercise should improve the function of your heart and lungs so that the rest of your body will work better as well. In general, any type of aerobic exercise can help with this component of physical fitness.