Smoking Affects Fitness Level

If you think the risks of cancer , hardening of the arteries, heart attacks, stroke, and emphysema are the only negative effects of smoking, you're wrong.

Your body's capacity for physical work depends on the amount of oxygen it can take in. Without oxygen the body cells cannot burn food for energy. And the only way oxygen can get into the body cells is through the process of respiration, which occurs on two different levels. In external respiration (what we call breathing) the lungs exchange carbon dioxide for oxygen from the atmosphere. Internal respiration involves the same exchange of gases between the bloodstream and body cells.

As the blood flows through the capillaries, it releases oxygen into the cells. Simultaneously, carbon dioxide passes from the cells into the bloodstream. The blood then goes to the lungs to expel its load of carbon dioxide and picks up a fresh supply of oxygen. Because the body tissues cannot store oxygen, they must be continuously resupplied by the blood stream.

Studies have shown that some cells are unable to carry oxygen for more than 12 hours after transporting carbon monoxide. If you smoke about 20 cigarettes, the oxygen supply in your circulatory system is reduced by five to ten percent. As a result, oxygen transport (the carrying of oxygen throughout the body by the blood cells) is limited considerably. This reduction in the oxygen-transporting capacity results in the corresponding reduction in the physical performance capacity during heavy work.

A non-smoker who trains regularly can expect a 10 to 20 percent increase in his maximum oxygen absorption. However, this training improvement is cut in half for the smoker whose oxygen uptake goes up only five to ten percent. Cigarette smoking has also been linked to an increased oxygen debt after exercise.

Perhaps the most conclusive evidence of smoking's effect on performance was revealed by Dr. Kenneth Cooper, author of Aerobics, in a 1968 study of 419 Air Force recruits. Cooper and his colleagues evaluated the airmen during their first six weeks of active duty by having them perform the 12-minute maximum running test. Although both smokers and non-smokers improved by the end of six weeks, those who smoked 10 to 30 cigarettes a day showed a significantly smaller change in fitness levels than did the non-smokers. Cooper concluded that smoking causes chronic problems which affect endurance and performance improvement during training.

Cooper also proved what other researchers have been saying for years--that the airmen's smoking increased their pulse rate and oxygen consumption during rest, raised their blood pressure, constricted certain blood vessels, decreased defusing capacity (the lung's ability to exchange gases with the bloodstream) and lung capacity and incurred a larger oxygen debt during exercise. Any or all of these symptoms can cut down on your body's overall efficiency.