Respiratory symptoms triggered by exercise are common among athletes and can significantly impact their performance and overall well-being. The main conditions that must be clinically evaluated include:
- Exercise-Induced Bronchoconstriction (EIB), with or without asthma
- Exercise-Induced Laryngeal Obstruction (EILO)
- Dysfunctional Breathing Patterns during Exercise (DBP)
Proper identification of these disorders allows for individualized and effective management, improving pulmonary health, optimizing performance, and reducing the risks associated with intense physical activity.
This article outlines the most common respiratory conditions seen in athletes, the clinically validated diagnostic methods, and the importance of sports medicine professionals providing personalized treatment strategies.
Respiratory Physiology in Athletes
Before discussing these conditions, it is important to distinguish between a physically active person and an athlete. While recreational exercisers engage in physical activity to improve fitness or health, athletes train regularly with the goal of participating in official sports competitions.
Weekly exercise duration serves to clearly differentiate between the groups.
- Physically active individual – 2,5 hours or more
- Recreational athlete – 4 hours or more
- Competitive athlete – 6 hours or more
- High Performance Athlete – 10 hours or more
During physical exertion, athletes may experience respiratory symptoms depending on exercise intensity, environmental conditions, genetic predisposition, and comorbidities. Accurate respiratory diagnosis enables athletes to continue training safely while optimizing performance.
Below, we describe some of the most common respiratory conditions in athletes, along with their clinical features and diagnostic and therapeutic considerations.
Exercise-Induced Bronchoconstriction (EIB)
Until recently, exercise-induced bronchoconstriction (EIB) in asthmatic patients was referred to as “exercise-induced asthma.” Some studies have proposed distinguishing between EIB with asthma (type 1) and EIB without asthma (type 2); however, this classification has not yet gained widespread acceptance.
The definition of EIB is a transient and reversible narrowing of the lower airways that occurs during physical exercise, and it can manifest in both individuals with bronchial asthma and those without a prior diagnosis of the disease.
Main Symptoms and Signs of EIB
- Dyspnea
- Cough
- Wheezing
- Chest tightness or discomfort
- Bronchial mucus production
These symptoms may occur during physical activity, but they more often appear 6–8 minutes after the completion of intense exercise. Symptoms typically last approximately 30–90 minutes and resolve spontaneously.
Diagnostic Tests for EIB in Athletes
While questionnaires are valuable for initial screening, confirmation requires pulmonary function testing.
Exercise Challenge Test (ECT). EIB is confirmed through an exercise bronchial provocation test measuring the Forced Expiratory Volume in one second (FEV₁) at 3, 5, 10, 15, and 30 minutes after at least six minutes of vigorous treadmill exercise.
A decrease of 10% or more in FEV1 compared to the baseline value before exercise confirms EIB. Severity can be classified according to three ranges:
Mild EIB: FEV1 ≥ 10% y ˂ 25%
Moderate EIB: FEV1 ≥ 25% y ˂ 50%
Severe EIB: FEV1 ≥ 50%. (In asthmatic patients under inhaled corticosteroids, a ≥30% FEV₁ drop may still indicate severe EIB).
Eucapnic Voluntary Hyperpnea (EVH). EVH testing is particularly valuable for young athletes when the ECT yields negative results.
If tests confirm that the patient has EIB, it is necessary to determine whether it is type 1 (EIB with asthma) or type 2 (EIB without asthma). For this purpose, pre- and post-bronchodilator spirometry is performed.
Exercise-Induced Laryngeal Obstruction (EILO)
EILO is a form of inducible laryngeal obstruction (ILO) characterized by temporary inspiratory narrowing of laryngeal structures during exercise, despite normal anatomy and function at rest. It is a recurrent condition in athletes that limits performance and quality of life. EILO is caused by paradoxical inspiratory adduction of laryngeal structures, leading to dyspnea and inspiratory stridor.
EILO is often misdiagnosed as asthma, EIB, or bronchial hyperresponsiveness (BHR), leading to inappropriate treatment. Recognizing EILO is crucial for sports medicine physicians, trainers, and coaches managing athletes with unexplained respiratory symptoms.
Prevalence of EILO
In adolescents, prevalence ranges from 5–8%, and may exceed 20% in populations where physical training is a daily activity (e.g., elite athletes, soldiers). Studies report 5.7–7.5% prevalence in adolescents and young adults, with no major gender differences. Among adolescent athletes, prevalence reaches 8.1%.
Although less common than exercise-induced bronchoconstriction (EIB), its signs and symptoms can be mistaken for those of EIB, and both conditions may coexist in approximately 4.8% of adolescents. In athletes presenting with unexplained respiratory symptoms, EILO can be an important differential diagnosis.
Diagnostic Evaluation for EILO
Adolescents and young adults are most commonly affected, making cardiopulmonary exercise testing (CPET) a valuable tool for distinguishing these conditions from asthma. Spirometry with bronchodilation does not confirm a diagnosis of EILO, but it can help identify a coexisting condition of asthma.
Definitive confirmation of EILO is achieved through flexible laryngoscopy. While resting videolaryngoscopy can provide relevant information, when clinical suspicion is high, the examination of choice is continuous laryngoscopy during exercise (CLE).
During this test, the patient performs exercise on a cycle ergometer equipped with a helmet that allows the videolaryngoscope to be fixed to the forehead and inserted into the upper airway after local anesthesia is applied to the corresponding nasal cavity. It is necessary to conduct the test using cardiopulmonary monitoring devices to obtain comprehensive physiological information.
CLE Scoring for EILO
The most widely accepted analysis of the record obtained through continuous laryngoscopy during exercise (CLE) is that of Maat et al. This system uses a scoring method that takes the following factors into account:
- Severity of laryngeal obstruction: Grade 0 (none) to Grade 3 (maximal)
- Exercise phase: early or maximal
- Location: glottic or supraglottic
According to a 2023 Expert Consensus, EILO diagnosis is confirmed when an inspiratory laryngeal closure ≥50% is observed at rest during provocation or when Maat grade ≥2 is recorded during CLE.
Dysfunctional Breathing Patterns during Exercise (DBP)
DBP refers to abnormal biomechanical breathing patterns that cause chronic or intermittent respiratory symptoms, particularly during high-intensity exercise.
Common signs and symptoms:
- Excessive breathlessness disproportionate to effort
- Inspiratory wheeze or stridor
- Throat tightness
- Frequent sighing
- Chest pain
- Throat clearing
- Dyspnea
- Paresthesia
- Dizziness
- Fatigue
Types of Dysfunctional Breathing Patterns
These disorders, which can occur independently or in combination, are often underdiagnosed or mismanaged as bronchial asthma, leading to the use of high doses of inhaled corticosteroids without achieving a clinical response. This situation can negatively impact the patient’s quality of life and increase healthcare-related costs.
At least five breathing patterns have been described:
- Hyperventilation Syndrome. Rapid respiratory rate, dizziness, and high tidal volumes near inspiratory capacity.
- Frequent Deep Sighing. Erratic breathing pattern with poor coordination of expiration and inspiration.
- Thoracic Dominant Breathing. Large tidal volumes with minimal inspiratory reserve.
- Forced Abdominal Expiration. Low lung volumes and reduced expiratory reserve.
- Thoracoabdominal Asynchrony. Poor coordination between chest and abdominal movement.
These breathing patterns can occur simultaneously and have been observed more frequently in young women and in individuals with high levels of anxiety, as well as in perfectionist athletes with obsessive traits, who are exposed to internal stress arising from their own high expectations (very ambitious goals or objectives) or external stress caused by defined events, such as a serious illness or bereavement.
Differential Diagnosis of Exercise-Induced Respiratory Conditions
To facilitate clinical understanding, the following table summarizes the key clinical and pathophysiological differences between EIB, EILO, and DBP.
Solutions for Assessing Respiratory Disorders in Athletes
Accurate differential diagnosis is essential to ensure effective treatment, improve quality of life, enhance performance, and reduce healthcare costs.
SCHILLER-GANSHORN provides advanced respiratory function assessment systems for sports and clinical environments. Our devices integrate spirometry (SpiroScout), body plethysmography(PowerCube Body+), and diffusion capacity testing (PowerCube Diffusion+) with SharpFlow ultrasonic sensors and cardiopulmonary exercise testing (CPET), offering a comprehensive analysis of ventilatory function and exercise response.
These tools are critical for the differential diagnosis of EIB, EILO, and DBP, enabling objective, reproducible, data-driven decisions that optimize athletic performance while protecting respiratory health.
Request a free demo today and discover how SCHILLER-GANSHORN can help you protect lung health, maximize athletic performance, and enhance diagnostic confidence. Our experts will take the time to understand your goals and guide you toward the most effective, cybersecure system for your needs.
DISCLAIMER: The availability of SCHILLER equipment may vary depending on the legal and regulatory requirements of each country. Please consult your local authorities or authorized SCHILLER representatives for information on the products available in your region.
REFERENCES
- Clemm, H. H., Olin, J. T., McIntosh, C., Schwellnus, M., Sewry, N., Hull, J. H., & Halvorsen, T. (2022). Exercise-induced laryngeal obstruction (EILO) in athletes: A narrative review by a subgroup of the IOC Consensus on ‘acute respiratory illness in the athlete’. British Journal of Sports Medicine, 56(11), 622–629. https://doi.org/10.1136/bjsports-2021-104704
- Vidal, A. G., Cortez, P. V., & Matamala, M. B. (2024). Evaluación y tratamiento de la sintomatología respiratoria relacionada con ejercicio en jóvenes atletas. Revista Chilena de Enfermedades Respiratorias, 40, 31–40.
FAQ: Exercise-Induced Respiratory Symptoms in Athletes
1 What are exercise-induced respiratory symptoms in athletes?
Exercise-induced respiratory symptoms include shortness of breath, wheezing, cough, and chest tightness that occur during or after physical activity. They may be caused by exercise-induced bronchoconstriction (EIB), exercise-induced laryngeal obstruction (EILO), or dysfunctional breathing patterns (DBP).
2 How can clinicians differentiate between EIB, EILO, and DBP?
Diagnosis relies on clinical evaluation and specialized tests. EIB is confirmed with pulmonary function testing or exercise challenge tests, EILO is diagnosed using continuous laryngoscopy during exercise (CLE), and DBP is assessed by observing abnormal breathing patterns during exertion.
3 What tests are used to evaluate exercise-induced respiratory symptoms?
Common tests include spirometry with bronchodilator, exercise bronchial provocation tests (ECT), eucapnic voluntary hyperpnea (EVH), cardiopulmonary exercise testing (CPET), and videolaryngoscopy during exercise (CLE) for EILO.
4 Can athletes continue training with exercise-induced respiratory symptoms?
Yes, with an accurate diagnosis and personalized treatment plan. Proper management of EIB, EILO, or DBP allows athletes to maintain safe training, optimize performance, and reduce risks associated with intense exercise.
5 How can SCHILLER-GANSHORN help manage exercise-induced respiratory symptoms?
SCHILLER-GANSHORN offers advanced diagnostic tools including spirometry, body plethysmography, diffusion capacity testing, and CPET. These systems provide objective data for accurate diagnosis and treatment, helping protect athletes’ lung health and performance.