Heat ExposureNCT06551168
Heat Acclimation in Females
A study testing Heat exposure in people with Heat Exposure and Blood Volume, run by Trinity Western University at 1 site in Canada.
Trial summary
Heat acclimation is when you repeatedly exposure yourself to heat so that your body adapts and better tolerates heat. This project will determine if completing a heat acclimation maintenance period after heat acclimation is more beneficial than heat acclimating alone for exercise performance in the heat. Read more about this study
- Who is it for?
- Ages 18 to 55 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Heat Exposure, Blood Volume, Cardiac Output
- What is being tested?
- Heat exposure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteCanada
- Study dates
- 1 Sep 2024to 1 Apr 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 55 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Familiar with the sport of cycling and own a bicycle and smart trainer (or a trainer and a power meter).
- Endurance athlete or currently engaging in endurance exercise
- Maximal oxygen consumption (VO2max) greater than 40 ml/kg/min
- Between the ages of 18 and 55
- Able to speak, read, and write in English
Who cannot join
- Unable to exercise
- Previous or current heat intolerance
- Pregnant
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Cardiovascular, Hematological, and Performance Response to Heat Acclimation in Healthy Trained Females
Heat acclimation is when you repeatedly exposure yourself to heat so that your body adapts and better tolerates heat.
This project will determine if completing a heat acclimation maintenance period after heat acclimation is more beneficial than heat acclimating alone for exercise performance in the heat. To determine this, participants will exercise in the heat before heat acclimation, after heat acclimation, and after heat acclimation maintenance. Researchers will assess the heart's pumping capacity, blood volume, body temperature, and exercise performance to determine which approach is more effective.
Read the detailed description
Purpose and Hypothesis: Global warming combined with increased frequency of heat waves exposes those who are working, exercising, or competing outdoors to considerable thermal strain. Excessive heat stress decreases exercise performance and can lead to heat illnesses. Deliberate serial exposure to natural (acclimatization) or artificial (acclimation) heat (HA) is the most efficacious method to defend homeostasis at rest and during exercise in hot environments. Our project will determine if three weeks of heat acclimation maintenance (HAM) further potentiates exercise performance in the heat than exercise performance measured after 10 days of HA in females.
Justification: Female participation in arduous occupations and professional sport is increasing. Presently a paucity of data regarding the female response to heat acclimation exist. Findings from this study will help females undertake effective and efficient strategies to mitigate thermal strain.
Research design: This is an experimental trial with a treatment and a control group. VO2max, plasma volume (PV), core temperature, and cardiac output will be measured pre-, mid-, and post-intervention. Participants will complete 10 sessions of HA over two weeks. Participants will then undergo three weeks of HAM with three heat sessions per week. A heat performance test will be completed pre-, mid-, and post-intervention to examine performance changes. A control group will complete the same test schedule but will not perform any HA or HAM.
Statistical analysis: Sample size will be 8 females in the experimental and 6 females in the control group. Data will be analyzed for normality using the Shapiro-Wilk test. Descriptive statistics will be presented as the mean and standard deviation. Statistical significance will be determined at P <0.05. A two-way repeated measure ANOVA will be used to measure differences between groups and hemodynamic, cardiovascular and performance variable differences pre- and post-HA, and pre- post-HAM. If significant effects are present, these will be followed by a post-hoc Tukey's test. Pearson's r correlations (two-tailed) will be conducted between VO2max, and intravascular volumes and heat performance test outcome.
- Conditions
- Heat Exposure, Blood Volume, Cardiac Output
- Being tested
- Heat exposure, Control group
- Keywords
- basic science
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Heat exposureOther
Participants will exercise at home while wearing a clothing ensemble over 19 one hour sessions. They will use validated perceptual scales to guide their effort and thermal sensation.
Control groupOther
Participants will exercise at home over 19 one hour sessions. They will use heart rate to guide their effort. The exercise will take place in cool conditions
| Study group | Role | What they receive |
|---|---|---|
| Heat Acclimation | Experimental | Participants in this arm will undergo heat acclimation sessions Receives: Other: Heat exposure |
| Control | Active comparator | Participants in this arm will undergo heart rate matched training volume Receives: Other: Control group |
What is being measured
The primary outcome is the main question the study is designed to answer.
Performance
Participants will complete a timetrial on a cycle ergometer in a heat chamber. Faster times following HA or HAM will be considered a marker of performance
Measured: 2 weeks and 5 weeks
Secondary outcomes (1)
Intravascular volumes
Expanded plasma volume or increased hemoglobin mass will be considered a positive response to heat acclimation
Measured: 2 weeks and 5 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Aug 2024
- Study start1 Sep 2024
- Primary completion1 Mar 2025
- Study completion1 Apr 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Heat ExposureStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- The experimental group will undergo heat acclimation The control group will not undergo heat acclimation. The control group will undergo heart rate matched exercise of the same quantity but in a cool environment
- Masking
- None (open label)
- Enrolment
- 15 participants (actual)
Sponsor and investigators
- Lead sponsor
- Trinity Western University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Anita Cote, Trinity Western University
- Investigators
- Anita T Coté, PhD, Principal investigator, Trinity Western University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06551168
- Sponsor's protocol ID
- 22G18
- Status last verified
- Apr 2025
- First submitted
- 9 Aug 2024
- Last updated
- 1 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 1 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Cardiovascular, Hematological, and Performance Response to Heat Acclimation in Healthy Trained Females
- ClinicalTrials.gov ID
- NCT06551168
- Acronym / sponsor ID
- 22G18
- Conditions
- Heat Exposure, Blood Volume, Cardiac Output
- Keywords
- basic science
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 15 participants (actual)
- Lead sponsor
- Trinity Western UniversityUniversity, hospital or other
- Study start
- 1 Sep 2024 (actual)
- Primary completion
- 1 Mar 2025 (actual)
- Study completion
- 1 Apr 2025 (actual)
- First posted
- 13 Aug 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Heat acclimation is when you repeatedly exposure yourself to heat so that your body adapts and better tolerates heat.
This project will determine if completing a heat acclimation maintenance period after heat acclimation is more beneficial than heat acclimating alone for exercise performance in the heat. To determine this, participants will exercise in the heat before heat acclimation, after heat acclimation, and after heat acclimation maintenance. Researchers will assess the heart's pumping capacity, blood volume, body temperature, and exercise performance to determine which approach is more effective.
Detailed description
Purpose and Hypothesis: Global warming combined with increased frequency of heat waves exposes those who are working, exercising, or competing outdoors to considerable thermal strain. Excessive heat stress decreases exercise performance and can lead to heat illnesses. Deliberate serial exposure to natural (acclimatization) or artificial (acclimation) heat (HA) is the most efficacious method to defend homeostasis at rest and during exercise in hot environments. Our project will determine if three weeks of heat acclimation maintenance (HAM) further potentiates exercise performance in the heat than exercise performance measured after 10 days of HA in females.
Justification: Female participation in arduous occupations and professional sport is increasing. Presently a paucity of data regarding the female response to heat acclimation exist. Findings from this study will help females undertake effective and efficient strategies to mitigate thermal strain.
Research design: This is an experimental trial with a treatment and a control group. VO2max, plasma volume (PV), core temperature, and cardiac output will be measured pre-, mid-, and post-intervention. Participants will complete 10 sessions of HA over two weeks. Participants will then undergo three weeks of HAM with three heat sessions per week. A heat performance test will be completed pre-, mid-, and post-intervention to examine performance changes. A control group will complete the same test schedule but will not perform any HA or HAM.
Statistical analysis: Sample size will be 8 females in the experimental and 6 females in the control group. Data will be analyzed for normality using the Shapiro-Wilk test. Descriptive statistics will be presented as the mean and standard deviation. Statistical significance will be determined at P <0.05. A two-way repeated measure ANOVA will be used to measure differences between groups and hemodynamic, cardiovascular and performance variable differences pre- and post-HA, and pre- post-HAM. If significant effects are present, these will be followed by a post-hoc Tukey's test. Pearson's r correlations (two-tailed) will be conducted between VO2max, and intravascular volumes and heat performance test outcome.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- The experimental group will undergo heat acclimation The control group will not undergo heat acclimation. The control group will undergo heart rate matched exercise of the same quantity but in a cool environment
| Arm | Type | Receives |
|---|---|---|
| Heat Acclimation | Experimental | Other: Heat exposureParticipants in this arm will undergo heat acclimation sessions |
| Control | Active comparator | Other: Control groupParticipants in this arm will undergo heart rate matched training volume |
Who may qualify
- Ages
- 18 to 55 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Familiar with the sport of cycling and own a bicycle and smart trainer (or a trainer and a power meter).
- Endurance athlete or currently engaging in endurance exercise
- Maximal oxygen consumption (VO2max) greater than 40 ml/kg/min
- Between the ages of 18 and 55
- Able to speak, read, and write in English
Key exclusion criteria (3 listed)
- Unable to exercise
- Previous or current heat intolerance
- Pregnant
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Heat exposureParticipants will exercise at home while wearing a clothing ensemble over 19 one hour sessions. They will use validated perceptual scales to guide their effort and thermal sensation. | Other | Heat Acclimation |
| Control groupParticipants will exercise at home over 19 one hour sessions. They will use heart rate to guide their effort. The exercise will take place in cool conditions | Other | Control |
Primary outcome
Performance
Time frame: 2 weeks and 5 weeks
Participants will complete a timetrial on a cycle ergometer in a heat chamber. Faster times following HA or HAM will be considered a marker of performance
1 secondary outcome
Intravascular volumes
Time frame: 2 weeks and 5 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Oct 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Anita T Coté, PhD principal investigator
Trinity Western University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Heat exposure in people with Heat Exposure and Blood Volume, run by Trinity Western University at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 1 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Performance (time frame: 2 weeks and 5 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Oct 2026.