|
Exercise
Bronchospasm in Recreational Athletes
By James
M. Kyle, MD and Joseph R. Leaman, MS, ATC
September 2002
Persons with exercise bronchospasm
can participate in sports if their condition is diagnosed early and managed
effectively. The goal of intervention for this airway response to exercise
should be to enhance sports enjoyment, with a secondary objective of maximizing
performance.
Exercise bronchospasm is a fairly common allergic response in physically
active people. Characterized by a transient increase in airway responsiveness,
exercise bronchospasm results in airflow obstruction that typically occurs
5 to 15 minutes after strenuous exercise. Classic symptoms include unusual
shortness of breath or wheezing after exercise. However, the only symptom
of exercise bronchospasm many athletes have is coughing after exercise.
Some athletes report symptoms of chest tightness or dizziness as well.
In preparation for the 1984 Summer Olympic Games in Los Angeles, the US
Olympic Committee conducted a screening program to identify athletes with
exercise bronchospasm. Sixty-seven of the 597 athletes screened (11.2%)
had exercise bronchospasm.(1) Only 26 of these world-class
athletes reported a history of previously documented asthma. However, 42
of the 60 athletes with exercise bronchospasm reported coughing, chest tightness,
or wheezing after strenuous exercise, which illustrates the phenomenon of
exercise bronchospasm in nonasthmatic, conditioned athletes. Forty-one medals,
including 15 gold medals, were awarded to these athletes in the 1984 Summer
Games.
As a result of the US Olympic experience, sports physicians have become
interested in routine screening for this condition in competitive athletes.
Adolescent student athletes are excellent candidates for screening. Early
identification and appropriate treatment of athletes who experience bronchospasm
after strenuous exertion can improve their enjoyment of sports participation
and help promote a lifelong commitment to fitness. In addition, many young
people who experience dyspnea avoid sports, but this is less likely in those
who are screened and treated for exercise bronchospasm.
Screening
Strategies
Athletes at risk
for exercise bronchospasm include those with a previous diagnosis of asthma
or environmental allergies and those with a history of coughing after strenuous
exercise. Researchers (2,3) have documented exercise
bronchospasm in 70% to 80% of athletes with asthma. Similarly, 40% of people
who have allergies experience exercise bronchospasm. The sensitivity of
coughing after strenuous exertion as an independent predictor of exercise
bronchospasm is not documented;(4) however, preliminary
results from a study of adolescent athletes at our institution suggest that
80% of athletes who cough after exertion have exercise bronchospasm confirmed
by an exercise challenge test.
The preseason physical examination provides a good opportunity to screen
athletes for a history of asthma.(5) Athletes who
may be reluctant to report a history of mild asthma usually report current
asthma medications. Student athletes who report that they use asthma medications
or inhalers (prescription and over-the-counter) should be considered at
risk for exercise bronchospasm. Up to 5% of 11- to 15-year-old athletes
have a history of asthma or current bronchodilator use identified during
sports physicals. Students reporting a history of environmental allergies
or listing allergy shots, antihistamines, or decongestants as routine medications
should also be considered at risk for exercise bronchospasm.
The tendency to cough or wheeze after strenuous sports activity may be the
only symptom reported by many young athletes with exercise bronchospasm.
In our experience, 11% of junior high school athletes respond affirmatively.
In addition to preseason physical Examination, coaches and athletic trainers
can observe athletes and identify those at risk for exercise bronchospasm.
They should suspect exercise bronchospasm if athletes cough after strenuous
exercise sessions, are easily winded in preseason drills, or are out of
shape in the middle of the season after having been well conditioned. Also,
athletes with exercise bronchospasm often have recurrent upper respiratory
tract infections and bronchitis during the competitive season. Athletes
who cough at rest or who report that they take antibiotics during the competitive
season are at high risk for exercise bronchospasm.
Diagnostic Evaluation.
When an athlete has symptoms that
suggest exercise bronchospasm, an exercise challenge test should be performed
to verify the diagnosis and grade the severity of bronchospasm. The challenge
test consists of 6 to 8 minutes of strenuous treadmill running at an intensity
of 85% to 90% of the predicted maximal heart rate.(3,6,7)
Most adolescent and young adult athletes can achieve an appropriate heart
rate response by running on a 10% grade at a speed of 4 to 6 mph.
An average of three resting peak expiratory flow rate (PEFR) measurements
should be calculated before testing. During the challenge test, peak flows
should be measured after 2 minutes of exercise and at 3-minute intervals
for 15 minutes after exercise using a hand-held Wright flow meter. The maximal
reduction in PEFR after exercise is compared with the resting PEFR to calculate
the percent change. (For example, an athlete with a resting PEFR of 400mL
and a reduction to 300mL after exercise would have a 25% reduction in PEFR.)
The diagnosis of exercise bronchospasm is based on a documented 10% or greater
reduction in
the PEFR or the one-second forced expiratory volume (FEV1) after exercise.(8)
Optimal Testing Conditions
A cool, dry environment is ideal for the exercise challenge test. When possible,
the relative humidity should be 40% or lower, and the ambient temperature
should be maintained at 75°. The challenge test should be performed
at least 4 hours after the athlete last used an inhaler and 24 hours after
taking sustained-release theophylline. If the athlete has engaged in strenuous
exertion on the day of the test, the test should not be given for at least
4 hours.
A positive testing environment will help young athletes maintain an educational
focus during the testing process. The staff should encourage the athletes,
look for opportunities to educate them, and reassure them that many of their
peers have the same airway response to exercise.
Alternatives to the challenge test include rowing machines, bicycle ergometers,
and stair-stepping machines. A 6-minute challenge test with documented exertion
and heart rate response is necessary to confirm exercise bronchospasm.
Positive exercise challenge test results are classified as mild, moderate,
or severe exercise bronchospasm based on the reduction in the percentage
of PEFR (table 1). Successful athletes usually have test results in the
mild to moderate classification. This includes student athletes with a history
of asthma who report using single or limited medications, and those without
asthma but who have a history of coughing after strenuous physical exertion.
| Table
1. Classification of exercise-induced bronchospasm |
| Descrease
%* |
Classification |
| 10-25 |
Mild |
| 25-35 |
Moderate |
| 35-50 |
Moderate
to Severe |
| <50 |
Severe |
*Percentage reduction in
peak expiratory flow rate or FEV(1) in postexercise
period compared with preexercise measurement.
Adapted from Anderson SD: EIA: new thinking and current management. J Respir
DIS 1986;7(11):48-61
Treatment Guidelines
Education
The first component of effective treatment of exercise bronchospasm
in adolescents and young adults is educating athletes, parents, and
coaches. Education improves compliance and encourages athletes with
exercise bronchospasm not to avoid exercise.
The physician should explain that exercise bronchospasm is an exaggerated,
reversible airway response to exercise that occurs in many athletes
and can be successfully managed in most cases. It is not a criterion
for exclusion from sports, nor is it a lung problem. Athletes need to
know that using an inhaler to enhance sports enjoyment and performance
does not mean they have asthma.
Nonpharmacologic Treatment
Nonpharmacologic treatment is helpful in cases of mild, seasonal exercise
bronchospasm, and as an adjunct to prescribed medical regimens. If the
athlete's aerobic fitness is poor, an exercise prescription should be
the first step in management, because exercise bronchospasm symptoms
can be improved with aerobic conditioning(9-11).
Athletes should be instructed to avoid exercise in a cold, dry environment,
because both conditions precipitate exercise bronchospasm. A long warm-up
period before athletic events can decrease the severity of bronchospasm
in some athletes. Many athletes experience a refractory period after
the initial bout of exercise bronchospasm and are resistant to additional
episodes of bronchospasm during the competitive event.(12-14)
Some athletes take advantage of this phenomenon by engaging in strenuous
preventive exercise. Adolescents with known or suspected environmental
allergies should consider selecting outdoor sports in which seasonal
allergy sensitivity won't be a problem.
Drug Therapy
Most athletes with mild to moderate exercise bronchospasm can be successfully
managed by using a B2 agonist inhaler 15 minutes
before practices and games. Cromolyn sodium can also be used as monotherapy
for exercise bronchospasm. Athletes with environmental allergies require
control of allergic rhinitis for optimal treatment of exercise bronchospasm.
In addition, a high index of suspicion should be maintained for subclinical
sinusitis in this group of athletes.
Athletes in whom pre-exercise treatment with an inhaler fails should
be screened for improper use of the inhaler. A spacer device might be
warranted. Inhalation spaced 2 minutes apart followed by a 10-second
breath hold is most effective.
When results of an exercise
challenge test indicate moderate to severe exercise bronchospasm, young
athletes typically report a history of asthma. Successful treatment
in these athletes
must be individualized and taken into consideration concurrent control
of daily asthma symptoms.
Repeat exercise
challenge test. The repeat exercise challenge test is an integral component
of management in young athletes with exercise bronchospasm. In addition
to documenting the effectiveness of current treatment regimens, repeat
testing promotes the athlete's awareness and understanding of exercise
bronchospasm.
Testing should
be repeated 4 to 6 weeks after the initial evaluation. Athletes are
instructed to continue current medications on the day of testing and
are observed during pretest inhaler treatment 15 minutes before the
exercise challenge. Treatment is considered successful if athletes report
subjective improvement in exercise bronchospasm symptoms and have a
50% or greater improvement in PEFR reduction during the challenge test.
If athletes have persistent post exercise PEFR reduction greater than
10%, they are candidates for additional non-pharmocologic and pharmacologic
interventions.(7)
Summary
Early diagnosis and effective management of exercise bronchospasm
in young athletes can have a substantial effect on their lifestyle decisions
by encouraging participation in physical activity. The goal of intervention
for this under-diagnosed airway response to exercise should be to enhance
sports enjoyment, with a secondary objective of maximizing performance.
References
| 1. |
Voy
RO: The US Olympic Committee experience with exercise-induced bronchospasm,
1984.Med Sci Sports Exerc 1986;18(3):328-330
|
| 2. |
Schroeckenstein
DC, Busse W: Exercise and asthma: not incompatible. J Respir Dis 1988;9(6):29-45
|
| 3. |
McCarthy
P: Wheezing or breezing through exercise-induced asthma. Phys Sportsmed
1989(7);17:125-130
|
| 4. |
Katz
RM, Siegal SC, Rachelefsky GS: Chronic cough in athletes. Clin Rev
Allergy 1988;6(4):431-441
|
| 5. |
Feinstein
RA, Soileau EJ, Daniel WA Jr.: A national survey of pre-participation
physical examination requirements. Phys Sportsmed 1988;16(5):51-59
|
| 6. |
Owens
GR: Optimal testing methods and preventive measures: exercise-induced
asthma. Consultant 1987;27(March):23-28
|
| 7. |
Konig
P: Exercise challenge indications and techniques. Allergy Proc 1989;10(5):345-348
|
| 8. |
Scoggin
C: Exercise-induced asthma. Chest 1985;87(1Suppl):48-49
|
| 9. |
Pierson
WE: Exercise-induced bronchospasm in children and adolescents. Pediatr
Clin North Am 1988; 35(5):1031-1040
|
| 10. |
Blumenthal
MN: Sports-aggravated allergies; how to treat and prevent the symptoms.
Phys Sportsmed 1990; 18(12):52-66
|
| 11. |
Mangla
PK, Menon MP: Effect of nasal and oral breathing on exercise-induced
asthma. Clin Allergy 1981; 11(5):433-439
|
| 12. |
Reiff
DB, Choudry NB, Pride NB, et al: The effect of prolonged submaximal
warm-up exercise on exercise-induced asthma. Am Rev Respir Dis 1989;139(2):479-484
|
| 13. |
Anderson
SD: Exercise-induced asthma: the state of the art. Chest 1985;87(5):191-195(Suppl)
|
| 14. |
Belcher
NG, O'Hickey S, Arm JP, et al: Pathogenetic mechanism of exercise-induced
asthma and the refractory period. N Engl Reg Allergy Proc 1988;9(3):199-201
|
Prior to founding the Kyle Sports Medicine Clinic
in Jacksonville, FL, Dr. Kyle was an
associate professor in the Department of Family and Community Health at
Marshall University School of Medicine, Huntington, West Virginia, and served
as a physician for the US Soccer team and emergency physician at Olympic
Stadium for the 1996 Atlanta Games. Mr. Leaman is Director of Sports Medicine
at Health South Rehabilitation in Parkersburg, West Virginia.
|
