Cardiorespiratory fitness is your ability to perform dynamic exercise using your large muscles to perform at moderate to high intensity for a prolonged period of time, according to the McKinley Health Center at the University of Illinois. Cardiorespiratory fitness is a good indicator of your overall health, measuring the efficiency in which your body delivers oxygen to your muscles and how well your muscles use that oxygen. Smoking adversely affects your cardiovascular and respiratory systems and reduces your cardiorespiratory fitness.
Cardiovascular Risks
Smoking causes coronary heart disease, the leading cause of death in the United States. Smoking narrows your arteries, which affects circulation and prevents oxygen-rich blood from reaching all the cells of your body. Smokers are at a higher risk for developing peripheral vascular disease, which involves damage to the blood vessels in your arms and legs. This disease causes pain, tissue loss, gangrene and other signs and symptoms. According to the Centers for Disease Control and Prevention, smoking also causes abdominal aorta aneurysm, or a weakening in your body’s main artery, your aorta.
Respiratory Risks
Smoking causes 90 percent of lung cancer deaths in men and 80 percent of lung cancer deaths in women, according to the CDC. Medical professionals estimate smoking causes 90 percent of all chronic obstructive lung disease. Smoking causes chronic obstructive lung diseases, such as bronchitis and emphysema, by damaging your airways and air sacs.
Pack-Years
Scientists describe a person's smoking habits in "pack-years." If you smoke one pack of cigarettes a day for 20 years, you have been smoking for 20 pack-years. A person who has smoked two packs a day for 20 years has been smoking for 40 pack-years. The more pack-years you smoke, the more smoking will affect your cardiorespiratory fitness.
VO2 Max
Medical professionals use the term VO2 max to describe your cardiorespiratory fitness. VO2 max measures the capacity of your heart, lungs and blood to transport oxygen to your muscles, along with measuring your muscle’s ability to use that oxygen efficiently. A high VO2 max means you have good cardiorespiratory fitness, and a low VO2 max indicates poor heart and lung health.
A study by NASA looked at 2,374 male and 375 female NASA employees and found that smoking decreased VO2 max minimally for those who smoked less than 20 pack-years. However, VO2 max was lower for those people who smoked more than 20 pack-years.
Relationship
Smoking decreases your cardiorespiratory fitness, and people who are fit are less likely to smoke. The American Diabetes Association magazine, "Diabetes Care," published a cardiorespiratory fitness study of 4,747 non-diabetic Japanese men. Men with the best cardiorespiratory fitness had the lowest body mass index and the lowest blood pressure. The study found the highest cardiorespiratory fitness group also had the lowest incidence of smoking. This study also notes cigarette smoking before the exercise test affected heart rate results, and that cigarette smoking is an independent risk factor for type 2 diabetes.
References
- University of Illinois: Predicting Your Cardiorespiratory Fitness Level; July 2007
- CDC: Health Effects of Cigarette Smoking; March 2011
- NASA: The Effect of Habitual Smoking on VO2max; Larry T. Wier, Richard R. Suminski, FACSM, et al
- Diabetes Care: Cardiorespiratory Fitness and the Incidence of Type 2 Diabetes; Susumu S. Sawada, PHD, I-Min Lee, MBBS, SCD, et al; July 2003
