Study findings suggest less than one quarter of asthmatic adults meet national exercise guidelines and, among this group, obesity may be a greater exercise deterrent actual asthma symptoms.

People with asthma may get caught in a vicious cycle, note Dr. Carol A. Mancuso and colleagues from Weill Cornell Medical College and the Hospital for Special Surgery in New York City.

"Obesity leads to worse asthma, which can be associated with less exercise, which predisposes to obesity and long-term (worsening) asthma," Mancuso told Reuters Health.

Since the high prevalence of obesity among people with asthma makes the relationship between body mass and exercise particularly important, Mancuso's team assessed exercise habits of 258 patients (75 percent women) who were 42 years old. The patients had mild-to-moderate asthma for 21 years on average and, in 37 percent, asthma was well controlled.

Overall, 40 percent of the patients were obese, 29 percent were overweight, and 31 percent were of normal weight, the researchers report.

Their findings, published in Annals of Allergy, Asthma and Immunology, show that of the obese group only 25 percent reported any exercise and just 14 percent met national guidelines of 20 to 30 minutes of exercise on 3 to 5 days each week.

By contrast, 46 and 20 percent of overweight asthmatics reported any exercise and meeting guidelines, respectively, while the corresponding percentages for the normal-weight asthmatics were 67 and 33 percent.

After factoring for age, gender, education, and asthma status, Mancuso's group found obesity most consistently and strongly associated with exercise habits. They report no association between short-term control or long-term severity of asthma symptoms and the exercise habits of the study participants.

Partaking in short bouts of different types of exercise may help people with asthma reach current exercise guidelines, the investigators suggest.

Mancuso further recommends physicians and patients "work together to manage obesity, select prudent exercise regimens, and use medications correctly to prevent symptoms induced by exercise."