Last updated: Apr 01, 2009
weight-lungs
(123RF)
Mike McBride, age 55, has climbed the 56 stories of Denvers Republic Plaza four times and has hustled up Chicagos 100-story John Hancock building. While he may sound super healthy, all the activity came after a life-changing moment: While hospitalized for a severe bout of pneumonia in 2005, McBride found out he was one of the more than 12 million Americans with chronic obstructive pulmonary disease (COPD), the fourth leading cause of death in the United States.


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.

McBrides 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 ones lung function, regardless of a persons 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 Institutes Division of Lung Diseases. “The more you weigh, the more work it is to carry it around. Its 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.)



How exercise helps COPD
A small percentage of people diagnosed with COPD lose weight due to the disease. But this often occurs in patients with late-stage emphysema and happens over a long period of time, says Dr. Weinmann. It is attributed to the excessive strain that comes with difficult breathing over a number of years, and physicians often prescribe supplements to help patients maintain a healthy weight.

For individuals who are able, exercise is important for good lung health. It has not been proven to heal the lungs of COPD patients, nor can it turn back the clock, but it reduces weight gain, strengthens the heart and respiratory muscles, helps deal with shortness of breath, and increases overall activity, which makes it easier to perform everyday tasks like walking up stairs, according to Michael Berry, PhD, a chair in the department of health and exercise science at Wake Forest University, in Winston-Salem, N.C.

“If the muscles of the rest of the body are well conditioned, the burden on the lungs to do a task is less,” Dr. Edelman says. “And if the muscles they use to breathe are conditioned, they are less likely to get respiratory muscle fatigue, which is one cause of respiratory failure.”

A 2007 article in the American Journal of Respiratory and Critical Care Medicine found that people who took part in regular physical activity experienced less intensive declines in lung function than those who did not. The study, which took place in Copenhagen over a 10-year period, also found that active smokers who worked out had a reduced risk of developing COPD.

McBride participates in races because they give him a goal and motivation for exercising, which he knows is good for his physical and mental health.

“When I am feeling healthier, I feel better spiritually and Im more receptive to people in general,” McBride says. “Exercise gets rid of the ‘Why bother, nobody cares, what difference does it make? feeling, which does sometimes happen.”