Asthma { Also See COPD | Lung Cancer | Allergy GET OUR NEWSLETTERS SHARE YOUR STORY Introduction Diagnosis Living With Care Treatment . ? ? ? ? ? ? ? ? ? ? ? ? . ATsai Causes Myth vs. Fact: Asthma and Exercise ATsai , Editor Asthma can affect many parts of a person's life, but exercise doesn't have to be one of them. Here are some commonly held misconceptions about what it means to exercise with asthma. Myth: Everyone with asthma experiences exercise-induced asthma. Fact: Although exercise is one trigger for asthma, which is called Exercise-Induced Asthma (EIA), not everyone with asthma necessarily experiences asthma during exercise. Some asthma is triggered by allergens, such as pollen, animal dander, dust, mold and cockroaches. Other types of asthma can be triggered by environmental irritants, such as cigarette smoke, while other people might react to certain medications, sulfites in foods or viral upper respiratory infections, such as the common cold. What Triggers Psoriasis? > If you have EIA, it means the tubes that bring air into and out of your lungs narrow during exercise, which causes symptoms of asthma. Symptoms will occur within five to 20 minutes into exercise, and can include wheezing, chest tightness, cough, shortness of breath and sometimes chest pain. [SLIDESHOW: 10 Signs of Exercise-Induced Asthma] Myth: Asthmatics should not exercise because it will cause an asthma attack. Fact: Maintaining a healthy diet and weight are important factors to controlling your asthma. So it’s important to maintain a healthy lifestyle. People with asthma can and should exercise; they just need to make sure their asthma is well-controlled through medication. This means taking a quick-relief inhaler shortly before physical activity to prevent symptoms while working out. Also, taking a long-term medication to help control inflammation can prevent asthma symptoms from occurring during exercise. If a person is experiencing frequent and severe symptoms of asthma while exercising, it could be a sign that the asthma is poorly controlled. It’s best to talk to your doctor about which medications you should increase, or if there are other options right for you, such as leukotriene modifiers. Myth: It’s better for asthmatics to work out in hot, humid air than cold air. Fact: Both dry, cold air and hot, humid air are asthma triggers. People with EIA are very sensitive to low temperatures and dry air. Normally, air is warmed and humidified by the nose, but during intense exercise, people tend to breathe through their mouths. This causes cold, dry air to reach the airways and lungs, which triggers asthma. A study from summer 2012 also looked at why hot, humid air also triggers asthma. Using a particular medication that prevents airway muscle contraction and increases airflow to the lungs, scientists found that hot, humid air causes asthma by activating sensory nerves in the airways, which are very sensitive to increases in temperature. They also found that people with mild asthma also experienced coughing when exposed to hot, humid air. [SLIDESHOW: Why Humidity and Cold Air Trigger Asthma] Myth: Being obese puts you at increased risk of dying from an asthma attack. Fact: Many people assume that people who are clinically obese have it worse when it comes to all health issues. However, a recent study looked at mortality rates and asthma exacerbations for obese and non-obese people with asthma. It found that although obese people are more likely to have an asthma exacerbation, non-obese people are more likely to have near-fatal exacerbations. Similarly, they looked at obese patients and non-obese patients with septic shock, and found that the obese patients were more likely to survive than non-obese patients. Researchers hypothesized that obesity blunts the pro-inflammatory cytokine response in our bodies. Myth: Exercise that requires ongoing exertion is better for asthmatics than short bursts of energy. Fact: Activities that require long periods of exertion, such as distance running, basketball, soccer or field hockey can be more difficult for people with asthma. It’s better to participate in either leisurely bike rides or hikes, or do activities that require short bursts of energy, such as baseball, football or short-term track and field. Cold weather sports, such as skiing and ice hockey can also present problems due to the cold, dry air associated with those activities. Sources: n.p. (2012). “Asthma and Exercise: Tips to Remember.” Allergy Asthma & Immunology. Retrieved from http://www.aaaai.org/conditions-and-treatments/library/asthma-library/asthma-and-exercise.aspx n.p. (2012, June 15). “How is Asthma Treated and Controlled?” National Heart Lung and Blood Institute. Retrieved from http://www.nhlbi.nih.gov/health/health-topics/topics/asthma/treatment.html Nationwide Children's Hospital (2012, June 6). Why hot, humid air triggers symptoms in patients with mild asthma. ScienceDaily. Retrieved from http://www.sciencedaily.com/releases/2012/06/120606164934.htm n.p. (2012, October 24). "Extra Weight Linked To Better Outcomes For Septic Shock, Asthma Exacerbation." Medical News Today. Retrieved from http://www.medicalnewstoday.com/releases/251849.php. Logo of bumcproc Proc (Bayl Univ Med Cent). 2003 Oct; 16(4): 388–391. PMCID: PMC1214556 Dispelling the myths of exercise and asthma Mark W. Millard, MDcorresponding author1 corresponding author Author information ? Copyright and License information ? A 16-year-old boy comes into your office and says he needs inhaled albuterol. He wants to play soccer but becomes short of breath when he is out on the soccer field. He currently uses the drug once a week during exercise, and he tells you that his albuterol keeps him from being so short of breath. When you listen to his chest, it is clear. His history includes no complaints of wheeze or cough; he has had no emergency department visits, hospital visits, or even sick days related to asthma. How would you proceed with this patient? With the paradigm of adolescence revolving around sports, it is not unusual for children to come into a primary care office with shortness of breath related to exercise. Right now, 20% of all children enrolled in the Dallas Independent School District have a history of asthma or current symptoms. Yet it is important to clarify the role of exercise in asthma and to dispel some commonly held misconceptions about exercise and asthma. This article deals with 3 such myths: that asthma stops patients in their tracks, that patients are “allergic” to exercise, and that managing exercise-triggered asthma requires specialized help. Go to: MYTH 1: MY ASTHMA STOPS ME IN MY TRACKS The widely used term “exercise-induced asthma” represents a misnomer: except in a very specific circumstance, exercise does not cause asthma but rather triggers asthmatic symptoms. Even so, many patients complain that asthma stops them in the midst of exercise and limits exercise ability. However, classic exercise-triggered asthma usually occurs after vigorous exertion. Appearing immediately after cessation of as little as 6 to 8 minutes of intense exercise activity, symptoms may require 30 to 60 minutes to resolve. McFadden and Gilbert documented this phenomenon by measuring lung function (in this case, forced expiratory volume in 1 minute, FEV1) during and after exercise (Figure ?(Figure11). Interestingly, lung function may actually improve during the first 10 minutes of exercise (1). Symptoms are followed by a refractory period of 1 to 2 hours in about half the patients, during which asthma symptoms cannot be induced again. Figure 1 Figure 1 The classic finding of exercise-induced asthma: lung function as measured by FEV1 improves during exercise but then plummets and requires 30 to 60 minutes to return to normal. Reproduced with permission from McFadden ER Jr, Gilbert IA. Exercise-induced ... Patients often report that they experience shortness of breath with just 2 to 3 minutes of vigorous exercise. However, Godfrey et al showed that following such a brief exercise period, lung function as measured by peak flow might decline by only about 10%, hardly clinically significant. Exercising for 10 minutes may trigger a more robust decline—in the above-mentioned report, the decline was 43% (2). The more intense the exercise, the greater the decrease in lung function, even for a short duration: at a treadmill grade of 5°, for example, decline was about 20%, and at a grade of 20°, it was 35% (2). Symptoms of exercise-triggered asthma are more easily triggered in cold, dry air, as opposed to warmer, moist air (Figure ?(Figure22) (3). For many years, Middle Easterners, among others, believed that it was better to exercise in dry air, and as a result athletic training facilities were built in the desert rather than by the Mediterranean Sea. Studies, however, showed the opposite: the more humid the air, the less likely is a decline in lung function. Cold air and low humidity probably affect the same things: heat and water loss. Figure 2 Figure 2 Forced expiratory volume in 1 minute (FEV1) declines much more in dry air (dashed line) than in humid air (solid line) 5 and 10 minutes after exercise. Reproduced with permission from reference 3. The impact of allergen exposure upon exercise-related asthma symptoms cannot be overstated. When children with documented exercise-triggered asthma are exposed to a single allergen challenge and are studied a week later, the mean decline in FEV1 changes from a modest 15% drop from baseline after exercise to a more robust drop of 29% (4). It is clear that the presence of airway inflammation and increased levels of inflammatory mediators alters and modulates the response to exercise. Physicians can recognize this phenomenon when patients indicate, for example, that they experience exercise-triggered asthma primarily in one season of the year. So, does asthma ever stop athletes in their tracks? On occasion it does, if exercise is prolonged. Vigorous exercise for more than 15 to 20 minutes may result in a decline of lung function in patients with asthma (5). But is this relevant to children who report shortness of breath while playing soccer or basketball? If an effort of more than 10 minutes at any given time produces prolonged dyspnea, then the answer might well be yes. But, as we shall see, many other things can cause shortness of breath besides exercise-triggered asthma. What we know about exercise-triggered asthma indicates that some sports are more or less likely to provoke asthma. Swimming, water polo, and diving seem to be the least asthmogenic, since the athletes breathe in warm, humid air while exercising. The next safest group includes football, baseball, sprinting, gymnastics, wrestling, golf, racquet sports, and boxing. More asthmogenic are long-distance running, basketball, soccer, cycling, and rugby. The worst sports for asthma are cross-country skiing, ice hockey, and ice-skating (6). Knowledge about how exercise-triggered asthma manifests and what makes it worse has led to 2 theories about its pathogenesis, one invoking airway heat loss followed by rapid rewarming as the primary mechanism, and the second positing airway dehydration leading to mediator release to explain exercise triggering (7). In the first case, McFadden's theory assembles data showing that asthmatics possess a hypertrophic as well as hyperplastic airway vasculature and that inappropriate airway rewarming occurs twice as quickly in asthmatic airways as in nonasthmatic airways during the first 30 seconds after exercise. He proposes that exercise-induced hyperpnea is associated with rapid airway cooling and that excessive rewarming causes vascular hyperemia, edema, and airflow obstruction (8). Whereas McFadden focuses on rewarming, Anderson concentrates on airway drying that leads to an increase in the osmolarity of airway lining fluid. With subsequent cellular dehydration comes bronchial epithelial and goblet cell injury, the release of inflammatory cytokines, mucus production, and vagal afferent stimulation. Cough and phlegm represent clinical consequences—even in normal elite athletes whose minute ventilation with prolonged training exceeds the normal airway resistance to dehydration. In asthmatics, airway desiccation and cellular activation occur in the context of preexisting airway inflammation. Mast cell activation, smooth muscle contraction, blood vessel constriction, vasodilatation, and plasma protein loss into airways also occur (9). Go to: MYTH 2: I'M “ALLERGIC” TO EXERCISE If asthma doesn't stop weekend athletes in their tracks, why can't they exercise? It's not because they are “allergic” to exercise, but rather because many things trigger shortness of breath, including deconditioning or hyperventilation, inhalant allergy, airway irritants, vocal cord dysfunction, and, with preexistent airflow obstruction, air trapping. Hammo and Weinberger studied child and adolescent athletes believed to have refractory exercise-triggered asthma. These athletes' chest discomfort and cough on exercise were attributed to asthma, but testing failed to confirm that diagnosis (10). The authors postulated that these individuals reached their anaerobic thresholds earlier, which led to hyperventilation and the sensation of chest discomfort potentially attributable to lactic acidosis. As already mentioned, some athletes with asthma present with symptoms related to allergic reactions to outdoor pollens or molds; these reactions may be confused with exercise-triggered asthma. Vocal cord dysfunction, common in adolescents, refers to a paroxysmal dyspnea triggered by inhalants, reflux, emotions, and/or exercise. Vocal cords normally abduct or open during inspiration and close during exhalation; with vocal cord dysfunction, cords adduct or close during inspiration. The symptoms often localize to the neck. While it mimics asthma, vocal cord dysfunction does not respond to standard asthma therapy. Vocal cord dysfunction can be inferred from examining flow-volume loops. McFadden and Zawadski described cases of “choking” (that is, unexpected poor performance) in athletes that were caused by vocal cord dysfunction and showed examples of flow-volume loops suggesting vocal cord dysfunction (11). Examples from our center before challenge and with symptoms show the flattening of the loop and the absence of the rapid upstroke of peak flow in the inspiratory loop associated with symptoms (Figure ?(Figure33). Figure 3 Figure 3 A flow-volume loop classic for vocal cord dysfunction; the normal, prechallenge tracing appears on the left for comparison. Dynamic air trapping during exercise occurs when obstructed airways act like check valves and trap air inside the chest. Patients feel as if their chest will “explode.” Healthy people experience no change in their inspiratory capacity during exercise. However, people with fixed airflow obstruction, such as chronic obstructive pulmonary disease or even chronic asthma with persistent “fixed” obstruction, sustain a decline in inspiratory function that reflects air trapping. So how do we determine whether symptoms are related to exercise-triggered asthma or another diagnosis? Clues for asthma include peak flow changes of>20% with symptoms, flow-volume loops, and atopic status. A greater than 10% change in FEV1 is diagnostic, although clinical significance may require more than a 15% to 20% change. Area under the curve analyses that integrate FEV1 changes over time may help quantitate the effect of exercise triggering (12). Dr. Donald Kennerly has said that the recovery period can be an important clue. Those who are deconditioned or who have vocal cord dysfunction will recover within 2 or 3 minutes, but those with asthma will require 30 to 60 minutes to recover. Similarly, symptoms during constant-level exercise suggest an allergen, air trapping, or vocal cord dysfunction, while symptoms after exertion suggest exercise-triggered asthma. Occasionally, we give patients an exercise challenge—asking them to run for 6 to 10 minutes either outside or in a laboratory while breathing compressed dehumidified air. An exercise challenge indoors with ambient air is much less likely to trigger asthma because of the warm, partly humidified, and allergen-free air within buildings. After exercise, we check them at 5-minute intervals for 15 to 20 minutes to see whether lung function decreases. Such a challenge allows us to investigate exercise-related symptoms, establish the diagnosis, assess response to therapy, and identify unrecognized bronchospasm. What about the term “exercise-induced asthma”? With all of the preceding discussion relating to exercise triggering, can exercise really cause asthma? The answer turns out to be yes: there does appear to be an asthma variant caused by extremes of exercise and cold air exposure. In this syndrome, elite athletes, especially those who train in cold climates, may experience non-atopic airway inflammation and subsequent airway hyperactivity. The best understanding of this process has come from studies on Alaskan sled dogs competing in the Iditarod race. Compared with nontrekking dogs, race participants demonstrated a dehydration injury of their airways leading to an inflammatory process associated with airway hyperactivity. Go to: MYTH 3: MANAGING EXERCISE-TRIGGERED ASTHMA REQUIRES SPECIALIZED HELP Despite the myth, if you treat the asthma appropriately, you will treat the exercise triggering. For the majority of patients, exercise triggering is the most visible sign of chronic asthma. Patients with asthma notice that, yes, they need their inhaler with exercise, but if you inquire further, you will often find that patients use their rescue medication much more often than just with activity. When treating asthma, it is useful to consider the Rules of Two (Table), which define when asthma symptoms are under control on the basis of national guidelines when patients use only a quick-relief medication, such as albuterol. The last of the four “rules,” that peak flow drops by 20%, relates especially to exercise-triggered asthma; exceeding a 20% decline with exercise would certainly require more than just a couple of puffs of albuterol before or with symptoms. Table Table “Rules of two” to determine whether patients need better asthma control There are nonpharmacologic ways to approach treatment of exercise-triggered asthma. One consideration is trigger avoidance. If exposure to some triggers can be reduced, the inflammatory process in the airways that drives bronchial hyperactivity can be downregulated, and less medication would be required. Tobacco smoke is the most common trigger and is extraordinarily virulent in aggravating asthma. Allergens and sinusitis are also very important triggers. Switching from one exercise to another can also help prevent attacks. For about half of patients, it is possible to exercise in such a fashion as to trigger a “mini-attack” to take advantage of the refractory period caused by the bronchodilating prostaglandins released by desiccated epithelial cells. It has been known that with repetitive exercise challenges, one can enter a so-called “refractory period” where further exercise fails to produce a decline in FEV1 and limiting symptoms (13). Generally, a warm-up consisting of 30-second sprints is much more effective than 15 minutes of continuous running in reaching the refractory period. If asthma and exercise triggering are not well controlled with the above nonpharmacologic approaches, stepwise medical therapy is indicated. A comparative study of common asthma medications showed that beta-agonists are the most potent reducers of exercise-triggered asthma; the next most effective were the cromones, such as nedocromil sodium (Tilade) and cromolyn sodium (Intal) (14) (Figure ?(Figure44). Another study showed that inhaled corticosteroids (one puff twice a day of budesonide [Pulmicort]) decreased the decline in FEV1 from 55% before treatment to 10% (15). Thus, very potent declines in exercise triggering can be achieved with inhaled corticosteroids, the most important medication for persistent asthma of any cause. Long-acting bronchodilators, such as salmeterol (Serevent) or formoterol (Foradil), improve overall asthma control when added to low-dose inhaled corticosteroids. However, their bronchoprotective properties “reset” after the first few doses and provide less long-lived relief from exercise triggering. For example, after the first few doses, salmeterol will continue to be protective in the first several hours after dosing but not long enough to protect from exercise triggering 6 hours and beyond from its initial dose (16). Figure 4 Figure 4 Effects of pharmacologic agents on exercise-induced asthma. Mean value for the percentage change in lung function usually measured as percentage fall in FEV1 or peak expiratory flow after exercise in the presence of a placebo or the active agent. Reproduced ... The primary care community has extensively employed leukotriene modifiers for exercise-triggered asthma. However, data show that patients who used montelukast sodium (Singulair) continue to experience postexercise declines of lung function averaging 15% to 20% compared with a control group experiencing a 30% drop in FEV1 (12). While this decline may represent a 50% reduction in the FEV1 effect of asthma triggering, the overall result falls much shorter than that from other therapies. In fact, the response to leukotriene modifiers is most heterogeneous: while a quarter of the patients who take a leukotriene modifier have an excellent response (<10% decline in FEV1), 75% of patients have a>10% decrease, including at least a full quarter who have no clinical effect at all. Go to: CASE DISCUSSION The case that opened this article was real. When we evaluated this 16-year-old with exercise-related shortness of breath, we found that he had a baseline FEV1 of 56% of predicted. After using a bronchodilator, his FEV1 improved to 74% of predicted. This patient with asthma probably stopped exercising because of air trapping, since his symptoms were manifested within a few minutes of exertion. We started him on a combination of fluticasone propionate and salmeterol (Advair 250/50) twice a day. Upon follow-up a month later, his symptoms and spirometric measurements had measurably improved, but he had decided not to pursue his soccer interests. I feel sure that if he had contracted a viral upper respiratory illness, he would have ended up in the emergency department or hospital; fortunately, we were able to prevent that by controlling his asthma. Go to: References 1. McFadden ER, Jr, Gilbert IA. Exercise-induced asthma. N Engl J Med. 1994;330:1362–1367. [PubMed] 2. Godfrey S, Silverman M, Anderson SD. Problems of interpreting exercise- induced asthma. J Allergy Clin Immunol. 1973;52:199–209. [PubMed] 3. Bar-Or O, Neuman I, Dotan R. 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Exercise-induced asthma: is it the right diagnosis in elite athletes? J Allergy Clin Immunol. 2000;106:419–428. [PubMed] 15. Pederson S, Hansen OR. Budesonide treatment of moderate and severe asthma in children: a dose-response study. J Allergy Clin Immunol. 1995;95:29–33. [PubMed] 16. Nelson JA, Strauss L, Skowronski M, Ciufo R, Novak R, McFadden ER., Jr Effect of long-term salmeterol treatment on exercise-induced asthma. N Engl J Med. 1998;339:141–146. [PubMed] Articles from Proceedings (Baylor University. Medical Center) are provided here courtesy of Baylor Health Care System CITATION: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1214556/