RESEARCH to PRACTICE
Decreasing Activity Limits for Asthma Patients
Zebulon V. Kendrick, PhD
THE PHYSICIAN AND SPORTSMEDICINE - VOL 28 - NO. 10 - OCTOBER 2000
Asthma disproportionally affects children, minorities, and people who live in urban areas (1,2) and is characterized by periodic episodes of wheezing, shortness of breath, tightness in the chest, increased mucus production in the lungs, and fatigue (2,3). Approximately 90% of all asthmatic patients experience exercise-induced asthma (EIA) that may develop slowly during exercise, with symptoms returning or intensifying during recovery (4).
Reaching the HP 2010 Goal
In the Healthy People 2010 report, the goal concerning respiratory diseases is to promote respiratory health through better prevention, detection, treatment, and education (table 1). Effective health management strategies for meeting this goal are to control factors that trigger asthma, such as upper-respiratory infections, allergens (pollens, animal dander, and dust), food or drug allergies, emotional upset (stress or anxiety), irritants (tobacco smoke, cold air, and strong smells), and exercise (1,2); use pharmacologic intervention(s) tailored to the severity of the disease; provide objective monitoring of lung function; and educate patients with asthma to become active participants in their own care (1-3).
Since asthma is reversible either spontaneously or with pharmacologic intervention (2), most medical models encourage those with asthma to participate in physical education classes, sports, and self-directed exercise as long as appropriate treatment and management strategies are employed (2,5). Unfortunately, many people with asthma feel overly anxious about experiencing EIA and generally lack appropriate instruction on how to exercise (6).
Drugs. Prophylactic medications such as cromolyn sodium, long-acting theophylline, leukotriene inhibitors, and corticosteroids are used to block specific mechanisms that may precipitate an asthma attack. The most common rescue medications are beta-agonists administered by aerosol inhalers; these quickly relax bronchiole smooth muscle. Preexercise administration of beta-agonists 15 to 30 minutes before activity may reduce or eliminate the symptoms of EIA for several hours. Patients with asthma must be adequately instructed about proper use of inhalers, particularly for emergency situations.
Exercise education. Objective 24-4 of the Healthy People 2010 report is concerned with decreasing the activity limitations of asthmatic patients. In keeping with this goal, physicians should provide patients with information about appropriate exercise environments and identifiable asthma triggers. Patients must know which medication(s) to take daily, before exercise, and during or following an asthma attack. It is also important to learn diaphragmatic breathing. Times for warm-up and cooldown should be extended to ensure that gradual temperature changes occur in the airways. Self-paced activities are generally more desirable than competitive sports.
Exercise intensity should be determined by symptoms and preconditioning of the patient. Most preconditioned people who have asthma can safely exercise at intensities of 50% to 60% of their age-predicted maximal heart rate. To train at higher intensities, the asthmatic patient should alternate high- and moderate-intensity exercise (7). On symptom-free days, patients may train at higher intensities. Also, some sports have different triggering thresholds. For example, swimming may be less asthmogenic than either running or cycling (8).
Asthmatic children. In children, regular vigorous exercise may reduce absenteeism from school, decrease days of hospitalization, allow for greater social interaction among peers, improve functional capacity (9), and reduce the incidence of asthma attacks (7,9). Since regular exercise provides potential health benefits, the asthmatic child's physician, parent, school nurse, and physical education teacher or coach should form a management team to ensure the avoidance of factors that trigger asthma and the availability of medications for both on- and off-site activities.
Exercise programs need to be flexible to accommodate changes in exercise capacity from asthma symptoms. Children also must learn to distinguish between the increased breathing associated with exercise and breathlessness associated with asthma. Children should be closely monitored for early symptoms of asthma and for the need for possible medical intervention when symptoms do not subside with appropriate rescue medication such as inhalers.
Future Research and Current Resources
Since the 1980s, biomedical research has led to better asthma management through tailored pharmacologic intervention and reduction of environmental factors that trigger asthma (1). More research is needed concerning age-appropriate education programs that encompass management of asthma, proper use of inhalers, and what procedures to follow when asthma worsens.
Dr Kendrick is a professor in the department of kinesiology at Temple University in Philadelphia. Address correspondence to Zebulon V. Kendrick, PhD, Dept of Kinesiology, Temple University, 134 Pearson Hall, Philadelphia, PA 19122; address e-mail to [email protected].