While you may hear the terms “cardiovascular” and “cardiorespiratory” used interchangeably, the former is a subset of the latter. Cardiovascular refers to your heart, blood vessels and blood. Cardiorespiratory includes all this and your breathing apparatus, too. Fitness buffs will better understand what’s happening in their bodies during exercise with a basic knowledge of these systems.
The heart of the cardiovascular system is, well, the heart. This muscular, four-chambered pump is only as big as a fist but must generate enough force to pump blood throughout the body. Arteries carry blood away from the heart. These narrow into arterioles and then tiny capillaries, the sites where oxygen and carbon dioxide are exchanged. The oxygen-depleted blood returns to the heart through veins.
The Respiratory System
The nasal cavity, or inside of your nose, the pharynx, larynx, trachea, bronchii and lungs compose the respiratory system. Once you breathe air in through your nostrils, it goes down your pharynx, through the layrnx, and then into the trachea, which is also known as the windpipe. The bronchii are the two small tubes that branch off from the trachea. Air passes through the bronchii before entering your lungs. When you look at drawings of the human body, you might think the bronchii simply empty into the lungs and the job is done. However, the respiratory system is much more complicated. The bronchii continue to branch off within the lungs into smaller tubes called bronchioles, then into about 300 million tiny miniature sacks called alveoli.
Cardiorespiratory Oxygen Exchange
The blood in your veins returns to the right side of the heart. By the time it gets there, it’s dropped off oxygen at cells around the body and picked up the waste product carbon dioxide. This blood is pushed into your lungs through the pulmonary artery, which is the exception to the rule of arteries carrying oxygen-rich blood. Once this blood enters your lungs, it trades carbon dioxide for fresh oxygen. The blood then flows into the left side of your heart through your pulmonary vein. From there, the heart squeezes it through the aorta and the cycle starts all over again.
Regularly doing cardiorespiratory exercise increases the efficiency of your heart and lungs. Other potential benefits include reducing your risk of cardiovascular disease, Type 2 diabetes, obesity, high cholesterol and, in the case of weight-bearing exercise, osteoporosis. You might also experience better sleep, improved moods and higher self-esteem. Cardiorespiratory activities include running, swimming, dancing, cycling and other activities that get your heart rate up through repetitive movements of your body's largest muscles. If you’re new to exercise and have any concerns about your physical condition in general or your heart in particular, consult your doctor before starting an exercise program.
- Folsom Lake College Physical Education Department: Cardiorespiratory Fitness & Energy Systems
- Sporting Performance: The Cardio Respiratory System
- American Council on Exercise’s Essentials of Exercise Science for Fitness Professionals; 2010
Teresa Bergen writes about fitness, health, yoga, travel and the arts. She is the author of "Vegetarian Asia Travel Guide" and has written hundreds of articles for publications online and off. Bergen also teaches yoga, spinning and group fitness classes, and is an ACE-certified personal trainer.