Exercising at moderate to high intensities is associated with higher rates of ventilation and a shift from nasal to oral breathing. This results in bypassing the nasal functions of filtering, heating, and humidifying inhaled air, thereby exposing athletes to various environmental factors that could affect their respiratory system.  It has been found that there is a high prevalence of upper and lower airway dysfunction in specific groups of competitive athletes, including rhinitis (allergic and non-allergic), exercise induced laryngeal obstruction, airway hyper-responsiveness, exercise induced bronchoconstriction, and asthma. There is also evidence of a higher prevalence of airway dysfunction in athletes competing in outdoor endurance sports, water sports in chlorinated pools, and winter sports. A sub-group of the IOC Consensus Group on “respiratory illness in the athlete” conducted a systematic review to publish the latest evidence around environmental conditions, such as air temperature, chemical exposure, pollution and altitude, known to be associated with non-infective acute respiratory illness in athletes.  

The clinical relevance of this review is that the findings can guide prevention and treatment strategies related to non-infective acute respiratory illness in athletes. Some of the key recommendations coming out of this publication include:

1. The clinical history of respiratory symptoms during exercise should systematically involve an investigation of the environmental conditions in which they occur.
2. For cold air and air pollution the pathophysiology of symptoms may be different from classical EIB/asthma. The therapeutic approach, including medication, should thus be adapted accordingly.
3. Suggested strategies to avoid harmful environments may be:

• Wearing a facemask to decrease particles or cold air inhalation,
• Wearing a nose-clip when swimming in a chlorinated pool,
• To decrease personal exposure either, for example by using a website or individual applications to follow pollens or air pollutant concentrations during peak hours or in ‘hotspot’ locations.

Reference for this summary:

V. Bougault, P.E. Adami, N. Sewry, et al., Environmental factors associated with non-infective acute respiratory illness in athletes: A systematic review by a subgroup of the IOC consensus group on “acute respiratory illness in the athlete” Journal of Science and Medicine in Sport, https://doi.org/10.1016/j.jsams.2022.03.003