Susceptibility of Cardiorespiratory Responses to Ozone During Cycling Exercise

NCT05473000 | Completed Results

• 1 other identifier: H22-01389
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

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.

Conditions

Ozone Exposure During Rest and Exercise

Keywords

Ozone; Air pollution; Exercise; Cycling; Susceptibility; Ventilation

Outcome Measures

Primary Outcomes (1)

• Time-to-exhaustion on Maximal Cycling Bout

  Measurement of time (in seconds) to volitional exhaustion on a constant work-rate cycling trial at 110% of previously determined maximal power output.

  From the beginning of the maximal constant work-rate cycling bout until volitional exhaustion occurs (roughly 1-5 minutes)

Study Arms (2)

Ozone (O3)

EXPERIMENTAL

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.

Behavioral: Exercise; Other: Ozone

Room air

SHAM COMPARATOR

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.

Behavioral: Exercise; Other: Room air

Interventions

Exercise BEHAVIORAL

Submaximal and maximal exercise

Ozone (O3); Room air

Ozone OTHER

Delivery of ozone air pollution at 170ppb

Ozone (O3)

Room air OTHER

Delivery of room air

Room air

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

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

Sponsors & Collaborators

• University of British Columbia: lead
• Natural Sciences and Engineering Research Council, Canada: collaborator

Study Sites (1)

University of British Columbia

Vancouver, British Columbia, V6T 1Z1, Canada

Location

MeSH Terms

Conditions

Motor Activity; Disease Susceptibility; Respiratory Aspiration

Interventions

Exercise; Ozone

Condition Hierarchy (Ancestors)

Behavior; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Respiration Disorders; Respiratory Tract Diseases

Intervention Hierarchy (Ancestors)

Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Oxygen; Gases; Inorganic Chemicals

Results Point of Contact

• Title: Dr. Michael Koehle
• Organization: The University of British Columbia

michael.koehle@ubc.ca

604-822-3838

Study Officials

• Michael Koehle, MD, PhD

  University of British Columbia

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, OUTCOMES ASSESSOR
• Masking Details: Air quality (ozone and room air) will be double-blinded; neither participants nor the primary researcher will know the randomized order of the condition.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: July 12, 2022
• First Posted: July 25, 2022
• Study Start: August 18, 2022
• Primary Completion: June 1, 2023
• Study Completion: June 1, 2024
• Last Updated: April 13, 2025
• Results First Posted: April 13, 2025

Record last verified: 2025-03

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)