Exercise-Induced Asthma - Recognizing and Managing the Problem
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Exercise-Induced Asthma
Recognizing and Managing the Problem
By Jon Heck, MS, ATC, and Kaley Abato, BS
______________________________________________________________________________
Jon Heck is the coordinator of athletic training at Richard Stockton College in Pomona, NJ. He
received his bachelor’s degree at William Paterson University and master’s degree from the
University of Florida.
Kaley Abato is currently a graduate student in the physical therapy program at Richard Stockton
College, where she also serves as a student athletic trainer. She received her bachelor’s degree in
biology at Stockton.
______________________________________________________________________________
As many as 12 million Americans have asthma. Contributing to 5,000 deaths a year,
asthma is the seventh-leading chronic condition in the nation. The number of cases is also on the
rise. The American Lung Association reported a 57 percent increase in asthma cases from 1982
to 1992 (28). Of interest to the athletic and female population, exercise-induced asthma (EIA)
affects up to 30 percent of athletes (18,20,22,30). Exercise-induced asthma affects approximately
10 percent to 23 percent of the general population (9,29) and 9 percent of non-asthmatics (1,25).
Studies report that 40 percent of individuals with allergic rhinitis (hay fever) (9,14,19,25,30) and
80 percent of asthmatics (2,3,11,19,25,29) experience EIA. Exercise-induced asthma has a
higher occurrence among children (22), although one in four outgrow it by adulthood (28).
Exercise-induced asthma is a reversible condition in which the smooth muscle in the
airways constricts in response to physical activity. Due to a various attack triggers, breathing
becomes so difficult that athletic performance declines significantly (9). A typical attack occurs
five to 15 minutes after physical exertion and peaks within six to eight minutes. Symptoms
gradually resolve within 30 to 60 minutes. This interval, known as the refractory period, lasts
between one and three hours after an attack. During the refractory period, the athlete’s
performance may return to about normal (4,7,22). The severity and frequency of attacks will
vary. Approximately 30 percent to 40 percent of individuals (24) will experience symptoms four
to six hours after exercise during a late phase response (22,29,30).
Signs and symptoms of EIA can appear during or after exercise. Each person has an
individual response and may not display all the same symptoms (9). Symptoms will also vary
among individuals. The signs and symptoms of EIA are listed in Table 1.
SPORTS MEDICINE UPDATETABLE 1
Signs and Symptoms of
Exercise-Induced Asthma
Obvious Signs and Symptoms:
Wheezing
Difficulty breathing
Chest tightness
Coughing
Problems with prolonged sessions of exercise
Subtle Signs and Symptoms:
Stomach pain/nausea
Fatigue
Inability to exercise in the cold
Chest congestion/discomfort
Frequent colds
Dry throat
Inconsistent performance
Headache
Several factors contribute to the occurrence and severity of EIA. Individuals with a
family history of asthma are genetically predisposed to having EIA (14). Environmental factors
such as cold, dry air; air pollutants; airborne allergens or irritants; and high altitude (11) can
trigger an attack (9,14,21,22,30). Exposure to food allergens such as shrimp, celery, egg whites,
peanuts, almonds or bananas up to two hours before activity may also provoke an attack (25).
The optimal conditions for exercise are warm, humid weather; minimal level of pollutants or
allergens; and a moderate altitude.
The duration and intensity of exercise also have an effect on EIA. High-intensity and
long-duration exercise result in increased risk of an episode, whereas brief, high-intensity
exercise bouts (e.g., 10 seconds of work, then 30 seconds of rest) or low-intensity, prolonged
exercise appear more tolerable (10). Other contributing factors include respiratory infections,
underlying bronchial hyperreactivity, the time period since the last EIA attack and a low fitness
level (22). Triggers of EIA vary greatly and athletes must identify those that promote their
symptoms.
The combination of seasonal conditions and the intensity and duration of exercise results
in some activities being more tolerable to individuals with EIA. Swimming is the most tolerable,
with long-distance running the least tolerable. Healthcare professionals should encourage
recreational athletes to pursue activities that do not involve cold, dry air or endurance exercise
(2). Trying to redirect competitive athletes from their sport will not be successful in most cases.
Table 2 classifies some common sports in regard to EIA risk.
SPORTS MEDICINE UPDATETABLE 2
Classifications of Sports and
Exercise-Induced Asthma Risk
Tolerable Sports/Activities:
Archery, baseball, circuit weight training,
downhill skiing, football, golf, gymnastics,
karate, kayaking, riflery, short-distance
running, swimming, tennis, volleyball and
wrestling
Less Tolerable Sports/Activities
Basketball, cross-country skiing, cycling, ice
hockey, ice skating, lacrosse, long-distance
running, rowing and soccer
Recognizing the Problem
Diagnosing EIA in athletes without chronic asthma can be difficult. This fact is
particularly true for athletes with more subtle symptoms. In addition, many athletes will
minimize or deny EIA symptoms as a “real problem” for participation. They may have been
dealing with the condition for years without treatment. Estimates of athletes with undiagnosed
EIA range from 5 percent to 30 percent (9,17).
For most athletic programs, a careful history is crucial in identifying EIA (17). This
diagnosis often is made on the basis of history alone (26). The preseason physical provides an
excellent opportunity to screen athletes. The past medical history portion of the examination
must include specific questions concerning asthma. The tendency to cough or wheeze after hard
physical activity may be the only symptom reported by many athletes with EIA (16). This
specific question should be included in every historical questionnaire.
There are several other risk identifiers. Athletes with a history of diagnosed asthma or
hay fever are likely to experience EIA. Athletes with EIA will frequently experience upper
respiratory tract infections or bronchitis and use antibiotics. Athletes who receive allergy shots or
regularly use antihistamines or decongestants are also candidates for EIA (16).
The treating physician must make a critical distinction whether the athlete has solitary
EIA or chronic asthma with exercise-induced episodes. This distinction is important regarding
treatment. The athlete with solely EIA will normally require only pre-exercise treatment. Those
athletes with persistent asthma will require daily anti-inflammatory therapy plus pre-exercise
treatment (26). This distinction may require pulmonary function tests using a computerized
spirometer in a physician’s office.
In-season observation by the coaching and athletic training staffs is also valuable in
identifying athletes at risk. Athletes with EIA will often become easily winded during prolonged
exercise; however, they tolerate short bouts well. They may describe not getting into shape as
SPORTS MEDICINE UPDATEfast as their teammates. The well-conditioned individual who becomes “out of shape” at
midseason may be experiencing EIA. Athletes, if questioned, also are likely to discuss
“conditioning difficulties” while they are involved in rehabilitation for other injuries.
Peak Flow Meter
A peak flow meter can be a useful tool in recognizing and managing EIA. It is
inexpensive, costing about $15 to $20, and is simple to use. A peak flow meter measures peak
expiratory flow rate (PEFR), or the fastest speed at which the athlete can blow air out of the
lungs after taking a maximal breath. Peak expiratory flow rate is a measure of how well the lungs
are moving air. Whether recognizing or managing EIA, a resting score must be obtained. This
figure will represent the baseline, or normal score. The highest of three trials should represent the
athlete’s PEFR score. The normal range for females is 450 milliliters to 490 milliliters (575
milliliters to 610 milliliters for males).
Undiagnosed athletes can be given an exercise test to help identify EIA. The exercise
challenge should last six to eight minutes at an intensity of 85 percent 90 percent of predicted
maximal heart rate (16). The athlete should not take the test within four hours of his or her last
EIA attack (16). The PEFR is then taken every three minutes over a 15-minute span, post-
exercise. A reduction of 10 percent or more indicates EIA (Table 3) (16). The peak flow meter
can also be used to manage EIA. After an attack, an athlete should not return to participation
until the PEFR is within 10 percent of his or her normal score.
TABLE 3
Exercise-Induced Asthma Classification
Exercise-induced asthma severity classification
based on percent reduction in peak expiratory flow
rate (PEFR) from pretest to post-exercise test (16):
10-25% Mild
25-35% Moderate
35-50% Moderate to severe
>50% Severe
Pharmacotherapy
Once diagnosed, prescription medication is the treatment of choice in successfully
managing EIA. Virtually every athlete can compete in his or her chosen sport with the
appropriate drug therapy. Olympic athletes with diagnosed EIA have gone on to medal at a rate
similar to their Olympic counterparts without asthma (1,9).
First-line defense drugs for EIA usually include a short-acting beta-agonist. Albuteral,
metaproterenol sulfate, pirbuterol acetate, and terbutaline sulfate all fit into this category (26).
Ninety percent of patients will be successfully managed with beta-agonists (1,6). This
medication is administered by a metered dose inhaler 15 to 30 minutes before exercise. The beta-
agonist inhalers are also used as a rescue treatment for rapid relief of an acute attack (6).
Salmeterol, cromolyn sodium or nedocromil can also be used in first-line defense.
SPORTS MEDICINE UPDATEAthletes who do not control their asthma with first-line therapy and adaptations may need
daily inhaled corticosteroids (26). The team physician should also re-evaluate these athletes for
chronic asthma that is exacerbated with exercise. The inhaled corticosteroids are used for daily
maintenance, and a first-line drug is still used before exercise (26).
Nonpharmacologic Treatment
Vitamin C
There appears to be an association between dietary vitamin C intake and asthma attacks
(13). Vitamin C is the major antioxidant substance present in the lining of the lungs (13,28). It
may be in this role that vitamin C battles the damaging effects of oxidant contaminants that can
contribute to an asthma attack. Oxidant contaminants include environmental pollutants, dirty air,
cigarette smoke and those produced by the body. A diet low in vitamin C is a risk factor for
asthma.
Recently, Cohen et al. (5) reported that vitamin C supplementation blocked an EIA attack
in 45 percent of the 20 patients in their study. Seven out of 11 other studies have found similar
effects on asthma with supplements of 1 gram to 2 grams of vitamin C. Cohen et al. gave their
patients 2 grams of oral vitamin C one hour before exercise. They could not predict which
patients would benefit from the supplementation. Of further interest, a subgroup of patients who
benefited from the single dose also blocked attacks for two weeks with 500 milligrams of daily
supplements.
It seems that vitamin C therapy warrants consideration as an adjunct treatment of athletes
with EIA. But there are some concerns. The 2,000 milligrams is a megadose that is 30 times the
Recommended Daily Allowance of 60 milligrams. The RDA for vitamin C is often considered
too low, however, and 200 milligrams to 300 milligrams may be more appropriate (13,27,28). In
addition, another study found the blood is 91 percent saturated with vitamin C at an intake of 400
milligrams and 100 percent saturated at 1,000 milligrams (27). This finding questions the need
for doses higher than 400 milligrams.
A reasonable approach for athletes may be to attempt a megadose of 1 gram to 2 grams
before exercise to see if it blocks their asthma episodes over several trials. If successful, they can
try daily supplementation at a level f 200 milligrams to 500 milligrams to determine if they get
similar benefits. This level of intake can be achieved through an appropriate diet of foods high in
vitamin C (Table 4). Overall, vitamin C is an inexpensive treatment option that is relatively safe
with a low side effect profile (8,12). If attempted, it should be combined with pharmacotherapy.
SPORTS MEDICINE UPDATETABLE 4
Foods Containing Vitamin C
Food Vitamin C (mg)
Strawberries (7 medium) 127
Bell peppers (1/2 cup) 95
Orange juice (6 oz.) 93
Chili peppers (1/4 cup) 91
Orange 80
Grapefruit juice (6 oz.) 70
Broccoli (1/2 cup) 62
Cantaloupe (1/4) 58
Brussels sprouts (1/2 cup) 48
Grapefruit (1/2) 47
Watermelon (1 slice) 46
Preventive Measures
The ideal treatment would involve avoidance of triggers, combined with modifying the
athlete’s exercise program. These practices are not always feasible when dealing with
competitive athletes. Within the athletic setting, the following preventive procedures can help
reduce the severity and occurrence of EIA. Athletes must experiment with time frames and
exercise intensity to find what works best for them.
1. Thirty to 60 minutes prior to activity, begin with a 10 to 15 minute warm-up (7,9,30)
involving stretching and light activity.
2. Begin short bursts of submaximal activity involving jogging or running (4,11,14,22,30). This
level should be sustained for five to 10 minutes. The objective is to have the athlete reach the
refractory period in which they can continue activity with fewer symptoms
(2,4,7,9,11,15,22,23,25).
3. Premedicate 15 to 30 minutes prior to practice/competition (7,11,23).
4. Post-competition, end with a 10 to 15 minute gradual cool-down (9,11), involving walking
and stretching. This cool-down helps to avoid provoking an EIA attack secondary to rapid
temperature changes in the airways (11).
Other management techniques can be incorporated into the athlete’s training program. A
high fitness level tends to decrease the need for medication and reduce the occurrence of
attacks (2,7,9,11,22). Since EIA can be triggered by rapid increases in a training program,
slowly progress the duration and intensity during training (15,22,23,25). The use of slow,
deep breathing techniques helps to avoid hyperventilation (11,15,30). Specific measures to
take during cold, dry weather include covering the mouth with cold-weather masks or scarves
(11,15,30). When possible, nasal breathing is also helpful. These techniques filter, warm and
humidify the air (2,4,7,911,22,23,25).
EIA Management Protocol
At Stockon College, we use a protocol that is derived from the Temple Asthma Watch
Program. It includes educating the athletes and coaches about their roles in the EIA
management process.
SPORTS MEDICINE UPDATE• During physicals, all athletes with suspected chronic asthma or EIA have their lung
volume measured with a peak flow meter. This measurement represents their “normal”
score. Each head coach then receives a list of all asthmatic athletes on his or her team.
• It is the coach’s responsibility to ensure that no athlete will practice or play without his or
her asthma inhaler readily available. Athletes who forget their inhaler may not participate
until they have it with them. It is worthwhile to note that an asthma inhaler at the practice
field does an athlete no good if he or she has an attack while on a distance run through
campus. The inhaler should accompany the athlete during such training.
• An athlete who has an attack at practice will be retested with the peak flow meter by the
student athletic trainers. After using the inhaler, the athlete must score within 10 percent
of his or her normal score in order to return to practice.
• Acceptable Treatment Range: The athlete who uses an asthma inhaler to premedicate
before competition and only once during competition to manage symptoms is in an
acceptable treatment range.
• Ineffective EIA Management: The athlete who needs an inhaler more than once during
practice (excluding premedication) represents ineffective treatment. Participation that day
will be terminated for any athlete who has two attacks during that exercise session. This
athlete then is referred to our team physician for a re-evaluation for chronic asthma and to
explore other prescription options.
• Asthma Emergency: An athlete who has an attack and the inhaler does not alleviate the
situation in five to seven minutes should be transported to the emergency room by an
emergency medical service.
A clear understanding among the coaching staff, athlete and medical staff is crucial. The
goal is to optimize the athlete’s performance while effectively managing the condition.
Asthmatics will have bad days or nights in which their symptoms may prevent full
participation. The athlete cannot fear repercussions of decreased playing time if he or she
is unable to practice. The 10 percent rule via the peak flow meter is an objective criteria
that takes the responsibility of participation status away from the athlete.
Conclusion
If untreated, exercise-induced asthma can be a hindrance to achieving top athletic
performance. The preseason physical is an excellent opportunity to screen athletes for
asthma and EIA. Once the problem is recognized, virtually every individual can complete
in his or her chosen sport with the appropriate drug therapy. The use of a peak flow meter
and the establishment of an asthma protocol help provide an optimal environment for
athletes with EIA to compete safely.
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Address correspondence to:
Jon Heck, MS, ATC
Athletic Training Services
Richard Stockton College
Jim Leeds Road
Pomona, NJ 08240
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