McBride, from Arvada, Colo., has always spent time in the gym. But he was also a smoker, one of the most common causes of COPD. It was during his hospital stay that McBride quit smoking and started walking. He participated in his first race, the Bolder Boulder, with liquid oxygen tucked in a backpack. He also plans to racewalk the Boston Marathon with a specialized oxygen cart in tow.
COPD refers to a group of diseases that includes emphysema, which is caused by damage to the air sacs in the lungs, and chronic bronchitis, which narrows the airways through swelling. There is no cure for COPD, a progressive disease that is usually attributed to smoking and typically diagnosed when people are in their 50s and 60s.
McBride’s physician and respiratory therapists recommended walking to keep his lungs strong. But even for people without COPD, maintaining a healthy weight and exercising regularly reduces strain on the lungs and strengthens respiratory muscles. For patients with COPD, research has shown that working out may slow the progression of COPD or help keep the disease in check.
How belly fat can harm your lungs
Having excess abdominal weight may lower one’s lung function, regardless of a person’s age, smoking history, or body mass index, according to a 2009 study published in the American Journal of Respiratory and Critical Care Medicine. Researchers studied 120,000 Parisians and found that abdominally obese patients (a 35-inch waist for women and a 40-inch waist for men) had poorer lung function than their slim-waisted counterparts. (And these were healthy, COPD-free people.)
One factor that may contribute to the problem is the inflammation associated with fat tissue. But excess fat may also constrict the lungs, making it harder to breathe.
“Carrying around extra weight is work,” says Gail Weinmann, MD, the deputy director of the National Heart, Lung and Blood Institute’s Division of Lung Diseases. “The more you weigh, the more work it is to carry it around. It’s like carrying a backpack. For someone who has a reduced capacity, the extra weight would be like carrying suitcases.”
The weight of the fat on the chest wall decreases the amount of room for the lungs. It also pushes up on the diaphragm, restricting its movement, particularly when bending over or lying down.
Being overweight puts a burden on your entire body, says Norman Edelman, MD, the chief medical officer at the American Lung Association. More oxygen must be moved around for the excess tissues; this causes the heart to work harder and places a greater burden on the cardiovascular system. It is also more difficult to breathe when someone is overweight. Dr. Edelman says diseases like asthma tend to be more severe in heavier individuals. (Many people with COPD have asthma too.)