Huffing and Puffing

A study published in the Scandinavian Journal of Caring Sciences in 2001 concluded that regular exercise increases the rate of abstinence from cigarettes.

The one-year study was organized into two nurse-managed groups where both groups underwent health education, behavioral modification, counseling and nicotine replacement, but only one group was also prompted to exercise.

The exercise group showed a higher rate of abstinence than the other and a lower rate of weight gain. This echoed results from previous trials.

These findings are promising but still preliminary. A review of several studies published in the journal Addiction in 2000 concluded that larger studies need to be done before it can be declared that exercise leads smokers to stop smoking.

When the Smoke Goes Out

What has been shown conclusively is that those who manage to quit smoking, by whatever means, have much to celebrate.

Within a day, the body's levels of carbon monoxide and nicotine decrease dramatically. The senses of smell and taste improve, and a person's tendency to cough decreases. According to the U.S. Surgeon General's 1990 Report on the benefits of smoking cessation, the resting heart rate begins to drop 20 minutes after quitting smoking and remains that way for years. After a few weeks, the blood circulation improves and the effort necessary to take each breath decreases. Cilia (tiny hair-like structures that move mucus out of the lungs) regain their normal function. The risk of infection lessens greatly as a result.

The risk for pancreatic and esophageal cancer decreases almost immediately. A year after quitting, the risk of heart disease is reduced by half, and after 15 years, the risk of heart disease and stroke is close to that of a nonsmoker. According to the 1990 surgeon general's report, quitting smoking for 10 years cuts the risk of lung cancer to half that of people who continue to smoke.

But there is an asterisk attached to these positives: Dramatically improved outcome is associated with quitting altogether -- which, not coincidentally, involves an overall improvement in lifestyle, including exercise.

Former smokers tend to have a healthier lifestyle, with less alcohol consumption, a better diet and a higher level of physical activity than current smokers. Former smokers are also more likely to practice preventive health measures and to undergo medical checkups, according to the surgeon general's report.

A Norwegian study just published in the journal Tobacco Control suggests that even more than the toxins of smoke, it is the associated poor diet, sedentary behavior and stress that appear to correlate with illness and premature death in smokers. Those who smoked very little -- people who often share the poor lifestyles of heavy smokers -- had risk levels similar to those who smoked the most.

The study looked at 43,000 people from the 1970s through 2002 and found that those who smoked very little (one to four cigarettes daily) had poor health outcomes. These light smokers were three times more likely to die of heart disease than nonsmokers; heavy smokers were four times more likely. Light smokers also had significantly higher death rates over the 30 year period -- 1.5 times higher generally -- than those who had never smoked. Going from zero to four cigarettes per day showed by far the greatest correlation in the study between smoking and associated death rates. In fact, it wasn't until cigarette consumption increased to 25 cigarettes per day that the corresponding death rate from all causes reached three times normal.

Since the amount of toxins delivered to the body increases the more cigarettes a person smokes, it is clear from the Norwegian study that other factors, namely the lifestyles of smokers (even light smokers) vs. nonsmokers, play an important role in the risk of disease and death.

Finally this year, Neal Johnston quit smoking. He had developed one too many cases of serious bronchitis, which caused difficulty breathing and required prolonged courses of antibiotics.

He responded to a particularly strong scare message I delivered to him one day, and he just stopped. He went cold turkey, without the help of aids, hypnosis or pills. He hasn't smoked in six months. He still exercises regularly.

Neal believes that regular exercise helped give him the strength to quit. I believe that the exercise helped protect him from dying. The preliminary research backs my observation that exercise is truly a positive force in a smoker's life, rather than an oddity.

I call Neal my test group of one, because I have only a few smokers in my practice who exercise regularly and judiciously. Many of those with heart disease and lung disease no worse than Neal's were never able to quit, and they died long before their chronic diseases progressed as far as his.

Certainly, a subset of patients has been so devastated by smoking that any exertion may present a strain too great for a severely damaged heart or lungs. Any smokers considering beginning an exercise program must consult with their physicians first. But for most smokers it seems clear that regular exercise initiates a healthy cycle that is likely to improve, and perhaps extend, their lives.

Marc Siegel is an internist and associate professor of medicine at the New York University School of Medicine. He is the author of "False Alarm: The Truth About the Epidemic of Fear" and the upcoming "Bird Flu: Everything You Need to Know About the Next Pandemic," both published by Wiley. Comments:health@washpost.com.