Ozone Exposure During Rest and Exercise
Conditions
Keywords
Ozone, Air pollution, Exercise, Cycling, Susceptibility, Ventilation
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.
Interventions
BEHAVIORALExercise
Submaximal and maximal exercise
OTHEROzone
Delivery of ozone air pollution at 170ppb
OTHERRoom air
Delivery of room air
Sponsors
Natural Sciences and Engineering Research Council, Canada
University of British Columbia
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Masking description
Air quality (ozone and room air) will be double-blinded; neither participants nor the primary researcher will know the randomized order of the condition.
Eligibility
Sex/Gender
MALE
Age
18 Years to 50 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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. |
Countries
Canada
Participant flow
Recruitment details
24 participants were screened for inclusion by the researchers during an initial study visit.
Pre-assignment details
22 eligible participants were randomized, with 20 opting to complete the two experimental visits in this crossover design.
Participants by arm
| Arm | Count |
|---|---|
| Ozone (O3) First, Then Room Air Participants completed submaximal and maximal exercise during a single study visit exposed to O3 (170ppb). After a 72 hour washout period, they then completed identical procedures exposed to room air. | 10 |
| Room Air First, Then Ozone (O3) Participants completed submaximal and maximal exercise during a single study visit exposed to room air. After a 72 hour washout period, they then completed identical procedures exposed to ozone (O3). | 10 |
| Total | 20 |
Baseline characteristics
| Characteristic | Room Air First, Then Ozone (O3) | Total | Ozone (O3) First, Then Room Air |
|---|---|---|---|
| Age, Customized Age | 28 years STANDARD_DEVIATION 6 | 28 years STANDARD_DEVIATION 6 | 28 years STANDARD_DEVIATION 6 |
| Race and Ethnicity Not Collected | — | 0 Participants | — |
| Region of Enrollment Canada | 10 participants | 20 participants | 10 participants |
| Sex: Female, Male Female | 4 Participants | 7 Participants | 3 Participants |
| Sex: Female, Male Male | 6 Participants | 13 Participants | 7 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 20 | 0 / 20 |
| other Total, other adverse events | 0 / 20 | 0 / 20 |
| serious Total, serious adverse events | 0 / 20 | 0 / 20 |
Outcome results
Primary
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.
Time frame: From the beginning of the maximal constant work-rate cycling bout until volitional exhaustion occurs (roughly 1-5 minutes)
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Ozone (O3) | Time-to-exhaustion on Maximal Cycling Bout | 209 seconds | Standard Deviation 59 |
| Room Air | Time-to-exhaustion on Maximal Cycling Bout | 235 seconds | Standard Deviation 81 |
p-value: 0.092t-test, 2 sided