Ground level ozone (O3) is a common airborne pollutant that is well recognized to cause negative respiratory symptoms and impair pulmonary function. The proposed study aims to have participants perform submaximal and maximal cycling exercise protocols exposed to both O3 and room air in a crossover design to evaluate how ventilatory patterns, pulmonary function, development of symptoms, and cycling performance are impacted by O3 exposure. Additionally, the investigators look to compare responses between O3 at rest and during exercise to predict which subjects may be most susceptible to adverse response, as considerable interindividual variability exists.

Inclusion Criteria:

• Healthy males between the age of 18 and 50
• Currently training and/or competing in endurance sport
• VO2max >60 ml/kg/min
• Able to communicate sufficiently using the English language

Exclusion Criteria:

• History of smoking
• Upper respiratory tract infection within the last 4 weeks
• Presence of any chronic respiratory disease

Adverse events were collected over the testing period (~4 weeks for participants).

All participants were at risk of adverse events due to exposure to low-levels of air pollution (O3) and maximal exercise.

Air quality (ozone and room air) will be double-blinded; neither participants nor the primary researcher will know the randomized order of the condition.