Susceptibility of Cardiorespiratory Responses to Ozone During Cycling Exercise

Investigating Susceptibility of Cardiorespiratory Responses to Ozone During Cycling Exercise Based on Resting Ozone Exposure

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.

Study Overview

• Status: Completed
• Conditions: Ozone Exposure During Rest and Exercise
• Intervention / Treatment: Behavioral: Exercise; Other: Ozone; Other: Room air

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • British Columbia
    • Vancouver, British Columbia, Canada, V6T 1Z1
      • University of British Columbia

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 46 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Ozone (O3); 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; Submaximal and maximal exercise; Other: Ozone; Delivery of ozone air pollution at 170ppb
Sham Comparator: 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.	Behavioral: Exercise; Submaximal and maximal exercise; Other: Room air; Delivery of room air

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in fraction of exhaled nitric oxide (FeNO)	Non-invasive airway inflammation biomarker (in part per billion, ppb)	Immediately and 30-minutes post-exercise and resting ozone exposure
Change in dyspnea	Feelings of shortness of breath measured via "Modified Borg Dyspnea Scale," where a response of "0" represents no feelings of breathlessness, and a response of "10" indicates maximal breathlessness.	Immediately prior to exercise, 10, 20, and 30-minutes into the submaximal constant work-rate cycling bout, immediately and 30-minutes following maximal cycling bout.
Change in symptoms	Development of symptoms related to the eyes, nose, throat, or general health, measured via a questionnaire developed by the investigators. A response of "0" indicates no feelings of the symptom, whereas a response of "5" indicates that the symptom is as bad as the participant has ever experienced it.	Immediately and 30-minutes post-exercise and resting ozone exposure
Change in rating of perceived exertion	Feeling of effort measured via "Borg Rating of Perceived Exertion," measured from 6 to 20. A response of "6" represents no exertion, while a response of "20" indicates maximal exertion.	10, 20, and 30-minutes into the submaximal constant work-rate cycling bout
Change in blood lactate values	Indication of exercise intensity and energy system contribution via measurement of blood lactate via finger-prick.	10, 20, and 30-minutes into the submaximal constant work-rate cycling bout

Collaborators and Investigators

• Sponsor: University of British Columbia
• Collaborators: Natural Sciences and Engineering Research Council, Canada
• Investigators: Principal Investigator: Michael Koehle, MD, PhD, University of British Columbia

Study record dates

Study Major Dates

• Study Start (Actual): August 18, 2022
• Primary Completion (Actual): June 1, 2023
• Study Completion (Actual): June 1, 2024

Study Registration Dates

• First Submitted: July 12, 2022
• First Submitted That Met QC Criteria: July 21, 2022
• First Posted (Actual): July 25, 2022

Study Record Updates

• Last Update Posted (Actual): April 13, 2025
• Last Update Submitted That Met QC Criteria: March 26, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: Exercise; Cycling; Air pollution; Ventilation; Ozone; Susceptibility
• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Disease Susceptibility
• Other Study ID Numbers: H22-01389

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No