HONOLULU -- Physical training programs involving aerobic exercise have a range of benefits for patients with asthma, an updated Cochrane review showed.
Patients who participated in the programs had improvements in asthma symptoms and cardiopulmonary fitness without any adverse effects on lung function, according to Madhu Chandratilleke, MD, of Queen Elizabeth Hospital in Woodville, South Australia.
There also was some evidence that the exercise programs improved health-related quality of life, she reported at the CHEST meeting here.
The lack of adverse effects is reassuring, she said, "and therefore there's no reason why asthmatic subjects who are stable could not participate in physical training programs, provided they are given proper medical advice."
She added, however, that there remains a need for well-conducted randomized controlled trials to assess the effects of exercise training, particularly on asthma symptoms and health-related quality of life.
Many patients with asthma forgo regular exercise because physical activity can increase airway resistance and induce bronchoconstriction. The low levels of activity then lead to chronic deconditioning, with some studies reporting that asthmatics tend to have lower cardiopulmonary fitness than their nonasthmatic counterparts.
Numerous physical training programs have been designed to improve fitness, neuromuscular coordination, and self-confidence in patients with asthma, although the results have varied.
A Cochrane review published in 1999 and determined to be up to date in 2005 looked at 13 studies of various training programs and found that they improved cardiopulmonary fitness without hurting lung function. There were no data on quality of life.
Chandratilleke and colleagues updated the review by adding six studies. The 19 randomized controlled trials included in the review were published between 1980 and 2011 and included a total of 695 participants ages 8 and older.
The exercise programs had sessions lasting at least 20 minutes at least twice a week for at least four weeks. Activities included swimming and running. The control was standard care.
Seven of the studies assessed the effect of physical training on asthma symptoms, although the data could not be meta-analyzed. Three reported improvement in asthma symptom-free days, one reported improvement in asthma severity, and three reported no change compared with the controls.
Of the studies looking at lung function, there was no difference between the pooled intervention and control groups in forced expiratory volume in one second (FEV1), forced vital capacity (FVC), or peak expiratory flow rate (P>0.05 for all).
Exercise capacity -- measured by maximum oxygen uptake, maximum expiratory ventilation, and work capacity -- improved with exercise training (P≤0.008 for all).
Five studies presented results for health-related quality of life, although each used a different tool to measure the outcome. Two of the studies reported improvements in all domains of quality of life and two reported improvements in total and physical limitation, symptom frequency, and psychosocial subscores. The fifth study reported no difference between the intervention and control groups.
Chandratilleke said that there were no usable data for bronchodilator usage and only one study that measured walking distance. The small numbers of studies and participants prevented subgroup analyses.
An additional limitation was the variation between the studies in intervention duration and design, she said.
Chandratilleke reported that she had no conflicts of interest.
Zalman S. Agus, MD Emeritus Professor
University of Pennsylvania School of Medicine and Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner