European Respiratory Society

Diagnosis, Prevention and Treatment of Exercise-Related Asthma, Respiratory and Allergic Disorders in Sports

Edited by K-H. Carlsen, L. Delgado and S. Del Giacco
Diagnosis, Prevention and Treatment of Exercise-Related Asthma, Respiratory and Allergic Disorders in Sports
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  • European Respiratory Society Monographs
  1. Page vii
  2. Page 1
    Correspondence: T. Haahtela, Dept of Allergy, Skin and Allergy Hospital, Helsinki University Central Hospital, FIN-00250 Helsinki, Finland. Fax: 385 947186500;

    Clinical asthma, exercise-induced bronchospasm and bronchial hyperresponsiveness are more common in competitive athletes compared with the general population. Various atopic conditions (e.g. pollen allergy) seem to be more common in summer sports athletes than in control subjects. Type of training and atopy are major risk factors for lower airway symptoms. Asthma is most commonly found in athletes performing endurance events, such as cross-country skiing, swimming or long-distance running. These athletes are repeatedly and strongly exposed to cold air and many inhalant irritants and allergens all year long. In symptomatic athletes, a mixed type of eosinophilic and neutrophilic airway inflammation often occurs leading in some individuals to functional abnormalities. Asthmatic symptoms in athletes are usually mild and at least partly reversible as they may disappear in those who stop intensive training.

  3. Page 5
    Correspondence: S. Bonini, IRCCS San Raffaele, Via Ugo de Carolis 59, IT-00136 Rome, Italy. Fax: 39 0635403017; E-mail:

    Rhinitis has a very high and increasing prevalence in athletes. Symptoms and mechanisms of rhinitis in athletes may differ in relation to the type of sports (e.g. swimming, running, skiing and boxing). Certainly, symptoms (and treatments) may affect performances, particularly in some environments (allergen content, quality of the air, etc.).

    Since rhinitis and asthma often coexist, even in the absence of allergy, all rhinitic athletes should be screened for asthma and exercise-induced bronchoconstriction according to the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines.

    The lack of common nomenclature and of standardised diagnostic procedures and flow charts makes it difficult to determine the prevalence of conjunctivitis in athletes. In fact, most of the studies refer to allergic rhinoconjunctivitis while data on vernal, atopic and contact lens conjunctivitis, as well as on contact ocular allergy, are very limited, although these conditions may significantly affect the well-being, vision and performances of athletes.

  4. Page 10
    Correspondence: P. Palange, Dipartimento di Medicina Clinica, Servizio di Fisiopatologia Respiratoria, Università of Rome “La Sapienza”, Viale Università 37, 00185 Rome, Italy. Fax: 39 064940421; E-mail:

    In this chapter, the relationships between exercise and lung function are analysed. The presence of airflow obstruction may impede an efficient ventilatory response to exercise because of the occurrence of dynamic hyperinflation. In normal subjects, bronchodilation may occur during exercise and this may also be true in asthmatics that are bronchoconstricted at rest. However, in a number of asthmatics with normal lung function at rest, bronchoconstriction may occur after a short submaximal exercise or even during it if the bout is prolonged. The mechanisms by which exercise-induced bronchoconstriction develop are triggered by thermodynamic events and involve inflammatory cells present in the airways at the time of exercise. Furthermore, recent data suggest that exercise may prime airway inflammation, thus leading to airway hyperresponsiveness in elite athletes.

  5. Page 19
    Correspondence: L. Bjermer, Dept of Respiratory Medicine and Allergology, University Hospital, 221 85 Lund, Sweden. Fax: 46 46146793; E-mail:

    Development of bronchial hyperresponsiveness (BHR) is complex, although there are common risk factors for all athletes. These include: 1) effort-induced immunosuppression with increased vulnerability to respiratory tract infections and 2) exercise-induced hyperpnoea causing the airways to be exposed to higher than normal levels of allergens, fine particles and gases, and to be subjected to dehydration stress from conditioning of large volumes of cold and dry air.

    Whilst exposure to airborne allergens is important in cyclists and runners, it is the irritants and gases that are important in swimmers and skaters. The bronchoscopy findings in skiers suggest that airway injury can occur simply from the dehydration stress. One potential outcome of dehydration stress is exudation of bulk plasma to restore the airway surface liquid. If the smooth muscle is repeatedly exposed to plasma products that have the potential to alter its contractile properties, then it is likely to become more sensitive to circulating mediators, such as leukotrienes and prostaglandins. In a winter athlete, this could lead to nonspecific BHR and in an atopic athlete the smooth muscle could become passively sensitised and develop BHR to allergens.

    Nonspecific BHR in athletes should not be necessarily interpreted as an indicator of asthma. Skiers and skaters have failed to benefit from treatment with either inhaled corticosteroids or leukotriene antagonists. Other strategies are required and these should include a reduction in environmental levels of potentially offending agents e.g. chloride content in swimming pools, fine particles and nitrogen dioxide in ice hockey halls.

    Winter athletes may benefit from using heat-exchange devices and summer athletes from masks that capture allergens. Due to the increased vulnerability to respiratory tract infections, hard training and competition in close relation to a recent upper respiratory tract infectious episode should be discouraged. These interventions may lead to a reduction in the prevalence of BHR in elite athletes.

  6. Page 35
    Correspondence: F. Drobnic, Dept of Sports Physiology, Olympic Training Center – CAR, Avda Alcalde Barnils 3-5, 08173 Sant Cugat del Vallés, Spain. Fax: 34 936754106; E-mail:

    Physical exercise imposes a certain level of stress on the respiratory tract to eliminate carbon dioxide and to supply the muscles with oxygen for energy production. This process requires increased airways ventilation above the normal resting frequency. The number of hours spent in training at high intensity levels by athletes is progressively increasing, and the number of recreational athletes is also growing and they are more concerned about their training schedules and intensities. Increased ventilation rate and oral breathing displaces pulmonary uptake of pollutants to more distal sites in the lung, depositing ambient air pollutants in the distal airways. This will affect the athlete, whether recreational or professional, who suffers from asthma or bronchial hypersensitivity. In contrast, it is known that competitive athletes have a high prevalence of asthma, exercise-induced asthma or bronchial hyperreactivity. Mechanisms for this association include increased inhalation of cold air, air pollutants, allergens, an increased response to respiratory infections, and increased parasympathetic tone. This chapter provides a review of outdoor and indoor sports practice and the environmental and climatological factors that can affect the airways of the asthmatic athlete.

  7. Page 48
    Correspondence: S.D. Anderson, Dept of Respiratory Medicine, 11 West, Royal Prince Alfred Hospital, Missenden Road Camperdown, New South Wales, Australia 2050. Fax: 61 295158195; E-mail:

    A history of symptoms of asthma in an elite athlete is not a reliable indicator of the need for treatment with a β2-agonist. Requesting an athlete to demonstrate either a response to a bronchodilator or an exercise test that reproduced the reason for use of a β2-agonist seemed the best approach to approve the use of a β2-agonist. For the Winter Games in Salt Lake City (UT, USA), laboratory-based tests were also suggested by the independent panel of the International Olympic Committee Medical Commission and included exercise, eucapnic voluntary hyperpnoea and methacholine challenge, and for Athens (Greece), hypertonic saline. Selecting realistic cut-off points to physical and pharmacological challenges, whilst permitting both types of test to be used, aimed at a high specificity for the diagnosis of asthma or exercise-induced bronchoconstriction. This approach meant the athlete could have confidence that asthma treatment was either appropriate or insufficient.

    Many athletes had only a past history (not current) of asthma. There was no evidence that athletes being treated with asthma drugs not requiring approval (inhaled corticosteroids, cromoglycate, nedocromil sodium, leukotriene antagonist), but whose application to use a β2-agonist was rejected, had any difficulties at either Salt Lake City or Athens. The submissions did not suggest that the athletes were at risk of inadequate management of asthma. Simplifying the challenges to a single cut-off point of a 12% fall in forced expiratory volume in one second for all the tests would have advantages and disadvantages. The major disadvantage is that procedures and guidelines for asthma are built on years of practice and data collection, and to move away from them is not advisable. More importantly, it would be a disadvantage to those who have exercise-related changes in lung function, which is the most important indication to seek approval to use a β2-agonist before a sporting event. In contrast, an increase >12% of either baseline or predicted seems appropriate to define a positive bronchodilator response in athletes.

  8. Page 67
    Correspondence: L. Delgado, Serviço de Imunologia, Faculdade de Medicina, da Universidade do Porto, Hospital S. João, PT-4200-319 Porto, Portugal. Fax:35 1225510119,

    Differential diagnoses of exercise-induced asthma in athletes include exercise-induced laryngeal dysfunction and abnormal laryngeal response to exercise in different, but closely related, entities, i.e. exercise-induced (paradoxical) vocal cord dysfunction, laryngeal prolapse and/or laryngomalacia. All these conditions present as exercise-induced inspiratory stridor with maximal exercise, usually resolving within 5 min of stopping. Gastro-oesophageal reflux disease is another possible diagnosis and/or comorbid factor in laryngeal dysfunction. Exercise-induced hyperventilation, swimming-induced pulmonary oedema and exercise-induced arterial hypoxaemia have all been reported in highly trained athletes and are linked to respiratory symptoms not directly related to bronchial obstruction. All of these conditions should be considered and ruled out with a thorough examination, as many athletes receive unnecessary treatment for asthma, which characteristically does not improve the exercise-induced respiratory symptoms.

  9. Page 73
    Correspondence: K-H. Carlsen, Voksentoppen BKL, Rikshospitalet (National Hospital) University Clinic, University of Oslo, Ullveien 14NO 0791 Oslo, Norway. Fax: 47 22136505; E-mail:

    Controlled studies of the protective effect of pharmacological treatment of exercise-induced bronchoconstriction (EIB( were reviewed. The studies were accepted only if they fulfilled certain criteria. In total, 164 studies were included in this review. It was found that inhaled β2-agonists offer a partial or complete (during the first 30 min after inhalation) protection against EIB, whereas the protection of oral β2-agonists was poor. Continuous treatment with β2-agonists induces tolerance of the protective effect, which seems to influence the duration rather than the magnitude of the protection. Treatment with inhaled steroids, xanthines and anti-leukotrienes offer a partial protection against EIB, while antihistamines and anticholinergic drugs are of less value in this context. Cromones offer a partial protection against EIB with no difference between cromoglycate and nedocromil. Furthermore, frusemide and calcium blockers have been shown to protect against EIB.

    A total of 13 controlled, randomised studies with a cross-over design of the effect of β2-agonists on physical endurance performance in healthy athletes or healthy young males were identified. In one study, a favourable effect of the drug was found (time to exhaustion), while in another study the placebo was favoured in this respect. In the other 11 studies no beneficial effect on endurance performance was found by β2-agonists. Of the eight studies examining the effect of β2-agonists on power output in athletes or non-athletes, one study favoured the active drug while the other seven studies did not find a difference between the active drug and the placebo. In one study, montelukast was not found to alter physical performance. There are reasons to believe that other anti-asthmatic drugs do not influence physical performance, but there are no studies supporting this assumption.

  10. Page 89
    Correspondence: P. van Cauwenberge, Dept of Oto-rhino-laryngology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium. Fax: 32 92404993; E-mail:

    Education of athletes, coaches, athletic trainers and physicians must make them more aware of upper and lower respiratory symptoms. If there is any suspicion of allergic rhinitis/conjunctivitis, asthma, exercise-induced asthma or other allergic respiratory disorders, the athlete needs to be subjected to thorough diagnostic procedures. Early recognition and correct diagnosis are the first step towards appropriate management. This includes education of the athlete on the nature of the condition and how to control it with or without medication.

    Prevention is a very important part of the therapeutic strategy. Individual environmental control measures and exercise advice have gained increasing interest, but are often impractical or even impossible in elite athletes. Consequently, pharmacological interventions and, in selected cases, immunotherapy have become an essential part of the prophylactic management. This also poses specific challenges in athletes, as only drugs complying with the anti-doping rules and providing optimal symptom control and minimal detrimental influences on performance can be selected.

    Finally, the allergic and/or asthmatic athlete should understand that they suffer from a common disease and that appropriate management will ensure that they can safely perform to the maximum of their ability. Allergic rhinitis, asthma and exercise-induced asthma do not have to be a restricting factor in sports and does not preclude successful competition at the highest level of sport.

  11. Page 102