Investigating Changes in Responses to Controlled Effective Doses of Ozone at Different Exercise Intensities

NCT06513754 | Withdrawn

• 1 other identifier: O3ED
• Study Type: interventional
• Target: N/A
• Locations: 1 country
• Sites: 1

Brief Summary

The project will look to investigate whether exercise during ozone exposure performed for a shorter duration at a higher intensity is more harmful than exercise performed for a longer duration at a lighter intensity. To assess this, participants will perform these exercise conditions with and without ozone exposure and researchers will assess changes in lung function, subjective symptoms, and breathing mechanics to determine which is more harmful.

Conditions

Ozone; Exercise Intensity

Keywords

Ozone; Exercise Intensity; Pulmonary Function; Ventilation; Dyspnea

Outcome Measures

Primary Outcomes (1)

• Pulmonary function

  forced vital capacity, forced expiratory volume in 1 second, forced expiratory flow over the middle half of FVC.

  Measured before, during, and after exercise (before, 45th minute of exercise, immediately after, and every 30 minutes after for an hour)

Secondary Outcomes (3)

• Rating of perceived exertion

  Measured during and after exercise (every 15 minutes during, immediately after, and every 30 minutes after for an hour)

• Sensations of Dyspnea

  Measured before, during, after exercise (before, every 15 minutes during, immediately after, and every 30 minutes after for an hour)

• Subjective Symptoms

  Measured before, during, after exercise (before, every 15 minutes during, immediately after, and every 30 minutes after for an hour)

Study Arms (4)

Ozone, High Intensity

EXPERIMENTAL

Participants will exercise for 45 minutes in the heavy intensity domain while exposed to 180 ppb ozone

Other: Ozone; Behavioral: Heavy Intensity

Ozone, Moderate Intensity

EXPERIMENTAL

Participants will exercise for 75 minutes in the moderate intensity domain while exposed to 180 ppb ozone

Other: Ozone; Behavioral: Moderate Intensity

Filtered Air, Heavy Intensity

SHAM COMPARATOR

Participants will exercise for 45 minutes in the heavy intensity domain while exposed to filtered air.

Behavioral: Heavy Intensity; Other: Filtered Air

Filtered Air, Moderate Intensity

SHAM COMPARATOR

Participants will exercise for 75 minutes in the moderate intensity domain while exposed to filtered air

Behavioral: Moderate Intensity; Other: Filtered Air

Interventions

Ozone OTHER

Ozone is a pollutant that forms as a result of nitrogen oxides or volatile organic compounds interacting with UV radiation. Ozone will be created via a generator in the lab

Also known as: O3

Ozone, High Intensity; Ozone, Moderate Intensity

Heavy Intensity BEHAVIORAL

Heavy intensity exercise between the first and second ventilatory threshold for 45 minutes

Filtered Air, Heavy Intensity; Ozone, High Intensity

Moderate Intensity BEHAVIORAL

Moderate intensity exercise below the first ventilatory threshold for approximately 75 minutes

Filtered Air, Moderate Intensity; Ozone, Moderate Intensity

Filtered Air OTHER

Exposure to filtered air (\<10 ppb ozone)

Filtered Air, Heavy Intensity; Filtered Air, Moderate Intensity

Eligibility Criteria

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

You may qualify if:

• Currently training and/or competing in endurance sport
• Maximal oxygen consumption (VO2max) greater than 60 ml/kg/min (males) or 50 ml/kg/min (females)
• Between the ages of 18 and 50
• Able to communicate sufficiently using the English language
• Taking hormonal birth control (female participants only)

You may not qualify if:

• History of smoking
• Upper respiratory tract infection within the last 4 weeks
• EIB, Asthma
• Presence of any chronic respiratory disease
• Current symptoms of, or current infection with COVID-19
• Pregnant or suspected pregnancy

Sponsors & Collaborators

• Michael Koehle: lead
• Natural Sciences and Engineering Research Council, Canada: collaborator

Study Sites (1)

Environmental Physiology Laboratory

Vancouver, British Columbia, V6T 1Z1, Canada

Location

MeSH Terms

Conditions

Respiratory Aspiration; Dyspnea

Interventions

Ozone

Condition Hierarchy (Ancestors)

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

Intervention Hierarchy (Ancestors)

Oxygen; Gases; Inorganic Chemicals

Study Officials

• Michael Koehle, MD, PhD

  University of British Columbia

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Masking Details: Both participants and investigator will be blinded to ozone status using nose clips
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Professor

Model Details: The study design to be employed for this study can be characterized as a double-blind cross over. ozone status (room air (\<10 ppb ozone) and 170 ppb ozone), exercise intensity (moderate and heavy), sex, lung size, and time will be independent variables

Study Record Dates

• First Submitted: May 25, 2024
• First Posted: July 22, 2024
• Study Start: September 1, 2024
• Primary Completion: April 1, 2025
• Study Completion: August 1, 2025
• Last Updated: March 30, 2025

Record last verified: 2025-03

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)