CHAPTER 5: Cardio-Respiratory System and Aerobic Training

The respiratory system, which consists of the lungs, airways, the chest, and the diaphragm, works with the cardiovascular system to deliver oxygen and remove carbon dioxide from body tissues. Cardiovascular systems include the heart, arteries, veins, and capillaries. Combined, they are often referred to as the cardiovascular system. Cardio refers to the heart, and vascular refers to the blood vessels. The cardiovascular system is responsible for transporting blood throughout the body. The blood transported through the cardiovascular system carries the nutrients and blood gases (oxygen, carbon dioxide) the body needs to function. The lungs are where the body gets rid of carbon dioxide and takes up oxygen (respiration). Pulmonary ventilation, commonly called breathing, permits the introduction and expulsion of air into and out of the lungs.

The efficiency of the cardiorespiratory system affects the body’s ability to meet the demands of physical activity and exercise. When the cardiovascular and respiratory systems are efficient, they are able to deliver the necessary oxygen and nutrients to the muscles quickly and efficiently. This enables the body to perform physical activities with more ease and less fatigue. On the other hand, if the cardiorespiratory system is not efficient, the body will quickly tire and fatigue during exercise. Individuals with poor cardiorespiratory efficiency may be more prone to exercise injuries and are also more likely to experience fatigue during exercise.

It is also essential for understanding the physiology of clients with heart or lung diseases and how to modify the exercise program accordingly.

Our focus in this chapter is on the underlying structures that ensure that the body gets the oxygen it needs and gets rid of carbon dioxide before it builds up to toxic levels.