Active Voice: Understanding Physical Activity for Asthmatic Patients
By Celso R.F. Carvalho, Ph.D., P.T., P.E.
Viewpoints presented in SMB commentaries reflect opinions of the authors and do not necessarily reflect positions or policies of ACSM.
Celso R.F. Carvalho, Ph.D., P.T., P.E., is Associate Professor in the Department of Physical Therapy, School of Medicine, at the University of São Paulo, Brazil. His research focus includes the benefits of aerobic exercise training in patients with persistent asthma. In the Feb. 2011 issue of Medicine & Science in Sports & Exercise® (MSSE), Dr. Carvalho coauthored related research entitled “Effects of Aerobic Training on Airway Inflammation in Asthmatic Patients.”
Ten years ago, an asthmatic patient’s mother asked me if her daughter could participate in sports and what benefits her daughter would obtain by exercising. The mother was afraid because some physicians recommended exercise for her daughter while others strongly suggested she avoid it. At the time, I did not know the answer, so I searched the literature, finding a systematic review showing that the only recognized benefits of exercise for asthmatic patients were increases in aerobic exercise capacity and reductions in the perception of dyspnea. However, the same review suggested there were more questions than answers. After that, I decided to begin a research program to determine the benefits of exercise for asthmatic patients.
In 2007, our group published a paper in MSSE showing that, after four months of aerobic training (40 minutes, twice a week), children with asthma presented with reductions in the intensity of exercise-induced bronchoconstriction and the amount of inhaled corticosteroid prescribed. In my opinion, these results suggested a possible anti-inflammatory effect of aerobic exercise in asthma. Therefore, we designed a study to evaluate such benefits. We reported findings from that recent study in the Feb. 2011 issue of MSSE, showing that patients with moderate and severe persistent asthma who engaged in aerobic exercise (40 minutes, twice a week) demonstrated a reduction in the eosinophil count in sputum and in levels of exhaled nitric oxide, both known as inflammatory markers in asthma. Those results were even more relevant because the patients who submitted to aerobic training also presented a 60 percent reduction in the number of days with asthma symptoms (cough, chest tightness, dyspnea and airway secretion). To our knowledge, this is the first published evidence that suggests a possible anti-inflammatory effect of aerobic training for asthmatic patients.
Our results must be viewed with caution, however, as we are not suggesting that medication should be substituted with exercise training because the observed anti-inflammatory effect occurred while the patients were optimally medicated (inhaled corticosteroids and bronchodilators). At the moment, we can only guarantee that aerobic exercise training can be performed even by patients with severe asthma if they are clinically stable (without crisis). During our study, we had some patients complaining that they could not walk two blocks without experiencing asthma symptoms; however, after three months, most were exercising at high intensity (>80% peak VO2) without any symptoms.
Increasing the level of physical activity in asthmatic patients seems a paradigm for everyone. First, it is important that all health professionals prescribe/indicate/orient their patients to keep moving. Second, we must gradually dispel the misconception that most asthmatic patients should be restricted from physical activity during their lifetime. Third, we should perform other studies to evaluate the benefits of other types of exercise, allowing patients to choose specific sports that they enjoy and that will benefit them. I have heard many times, from both asthmatic patients and other adults, that they simply do not like to walk or run.