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.

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