April 23, 2009

Q. I just quit smoking after six years. I'm now starting to exercise and I find myself very out of breath. I'm not sure if this is from smoking or being inactive. Has smoking hindered my ability to jog?

A. Your breathlessness is more likely due to your lack of fitness than your smoking, says family physician Donald Brideau, M.D., a clinical professor at Georgetown University in Washington, D.C., and a spokesman for the American Heart Association. "Within three to five days, if you haven't had a single cigarette, your blood cells' ability to carry oxygen to your heart and muscles will be back to normal."

Smoking does cause lung damage that can reduce a smoker's cardiovascular exercise capacity; however, Brideau says, "the lung damage after six years of smoking would probably be minimal." (But it takes 10 years or more after you quit before your lung-cancer risk is the same as if you had never smoked.)

The carbon monoxide in cigarettes displaces oxygen from red blood cells, Brideau explains. So, a smoker has less oxygen going to her heart and muscles, providing her with less energy to exercise. The more you smoke, the less oxygen you have available. Even as little as one cigarette a day reduces your blood's ability to carry oxygen.

Since you haven't exercised for several years, it's only natural that you find yourself out of breath quickly. Your heart and lungs are not as strong as a fit person's are (or as strong as a nonsmoker's are yet). So you're not able to pump as much blood with each heartbeat or take in as much air with each breath.

Instead of starting with a jogging program, try walking, which is not only less demanding on your heart and lungs but also less stressful on your joints. After several weeks, or perhaps even a few months, you may want to gradually work in some jogging. For instance, after walking for 10 minutes, try alternating 30 seconds of jogging with two minutes of walking. Eventually, you'll find that you can do workouts easily that used to leave you gasping for breath.