Susceptibility of Cardiorespiratory Responses to Ozone During Cycling Exercise

Not Applicable

Completed

• Conditions: Ozone Exposure During Rest and Exercise
• Interventions: Behavioral: Exercise; Other: Ozone; Other: Room air

• Registration Number: NCT05473000
• Lead Sponsor: University of British Columbia

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2022-07-12
• Study First Submitted QC: 2022-07-21
• Study First Posted: 2022-07-25
• Study Start: 2022-08-18
• Primary Completion: 2023-06-01
• Study Completion: 2024-06-01
• Results First Submitted: 2024-06-20
• Status Verified: 2025-03
• Results First Submitted QC: 2025-03-26
• Last Update Submitted: 2025-03-26
• Results First Posted: 2025-04-13
• Last Update Posted: 2025-04-13

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 20

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Room air	Exercise	Participants of the sham group will perform sub-maximal exercise (power output associated with 10% below anaerobic threshold for 30 minutes) and maximal exercise (time-to-exhaustion test at 5% above previously determined maximal power output) on a cycle ergometer while inhaling room air during each exercise session.
Ozone (O3)	Exercise	Participants of the experimental group will perform sub-maximal exercise (power output associated with 10% below anaerobic threshold for 30 minutes) and maximal exercise (time-to-exhaustion test at 5% above previously determined maximal power output) on a cycle ergometer while inhaling 170ppb ozone delivered continuously during each exercise session.
Ozone (O3)	Ozone	Participants of the experimental group will perform sub-maximal exercise (power output associated with 10% below anaerobic threshold for 30 minutes) and maximal exercise (time-to-exhaustion test at 5% above previously determined maximal power output) on a cycle ergometer while inhaling 170ppb ozone delivered continuously during each exercise session.
Room air	Room air	Participants of the sham group will perform sub-maximal exercise (power output associated with 10% below anaerobic threshold for 30 minutes) and maximal exercise (time-to-exhaustion test at 5% above previously determined maximal power output) on a cycle ergometer while inhaling room air during each exercise session.

Primary Outcome Measures

Name	Time	Method
Time-to-exhaustion on Maximal Cycling Bout	From the beginning of the maximal constant work-rate cycling bout until volitional exhaustion occurs (roughly 1-5 minutes)	Measurement of time (in seconds) to volitional exhaustion on a constant work-rate cycling trial at 110% of previously determined maximal power output.

Trial Locations

Locations (1)

University of British Columbia; 🇨🇦 Vancouver, British Columbia, Canada