HeatNCT04053465
Heat Acclimation, Hand Cooling Efficacy, and Adaptation Maintenance.
A study testing Heat acclimation and Exercise in a cool environment in people with Heat, run by University of Connecticut.
Trial summary
This study had three aims: 1. To determine the impact of consecutive days of exercise on thermoregulation and cardiovascular strain. 2. To determine the efficacy of a hand cooling device to cool individuals throughout a heat acclimation period. 3. Read more about this study
- Who is it for?
- Ages 18 to 35 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Heat
- What is being tested?
- Heat acclimation and Exercise in a cool environment
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 34 participants
- Where
- No sites listed yet
- Study dates
- 1 Aug 2014to 31 Mar 2015
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 35 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- no chronic health problems
- no previous history of exertional heat stroke within the past 3 years
- no history of cardiovascular, metabolic or respiratory disease
- no current musculoskeletal injury that limits physical activity
Who cannot join
- women
- exercise less than once per week
- VO2max < 45 ml/kg/min
About this study
Official title: The Effect of Heat Acclimation on Repeated Bouts of Strenuous Heat Stress, Hand Cooling Efficacy, and the Maintenance Thereof.
This study had three aims:
- To determine the impact of consecutive days of exercise on thermoregulation and cardiovascular strain.
- To determine the efficacy of a hand cooling device to cool individuals throughout a heat acclimation period.
- To assess the maintenance of thermoregulatory and cardiovascular adaptations derived from heat acclimation during a 25-day intermittent exercise-heat exposure protocol.
Read the detailed description
Participants completed 14 days of exercise heat acclimation in either a hot or cool environment, followed by a heat or cool exercise exposure every 5th day for 25 days. Cardiovascular, thermoregulatory, and perceptual strain were measured throughout exercise each day. Hydration assessment and stress response via blood biomarkers were measured before and after exercise. Aerobic capacity was measured before and after heat acclimation as well as after the intermittent exercise-heat exposure. Hand cooling was implemented periodically during exercise-heat stress visits to determine cooling efficacy before and after heat acclimation.
- Conditions
- Heat
- Being tested
- Heat acclimation, Exercise in a cool environment
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Heat acclimationOther
14 days of aerobic exercise in a hot environment
Exercise in a cool environmentOther
14 days of aerobic exercise in a cool environment
| Study group | Role | What they receive |
|---|---|---|
| Exercise in heat group | Experimental | Exercise in a hot environment Receives: Other: Heat acclimation |
| Exercise in cool group | Placebo comparator | Exercise in a cool environment Receives: Other: Exercise in a cool environment |
What is being measured
The primary outcome is the main question the study is designed to answer.
Internal Body Temperature
Rectal temperature was assessed five days following measurement at baseline.
Measured: 5 days
Secondary outcomes (1)
Heart Rate
Heart rate was assessed five days following baseline.
Measured: 5 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Aug 2019
- Study start1 Aug 2014
- Primary completion31 Mar 2015
- Study completion31 Mar 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for HeatStudies 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
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 34 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Connecticut
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Douglas J Casa, University of Connecticut
- Investigators
- Douglas J Casa, PhD, Principal investigator, University of Connecticut
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04053465
- Sponsor's protocol ID
- H14-188
- Status last verified
- Feb 2020
- First submitted
- 7 Aug 2019
- Last updated
- 27 Feb 2020
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Aggregate data can be shared upon request.
Publications
Pryor RR, Pryor JL, Vandermark LW, Adams EL, Brodeur RM, Armstrong LE, Lee EC, Maresh CM, Casa DJ. Short term heat acclimation reduces heat strain during a first, but not second, consecutive exercise-heat exposure. J Sci Med Sport. 2021 Aug;24(8):768-773. doi: 10.1016/j.jsams.2021.03.020. Epub 2021 Apr 6.
PubMed 33846088
Study at a glance
From the registry record, last updated by the sponsor on 27 Feb 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Heat Acclimation on Repeated Bouts of Strenuous Heat Stress, Hand Cooling Efficacy, and the Maintenance Thereof.
- ClinicalTrials.gov ID
- NCT04053465
- Acronym / sponsor ID
- H14-188
- Conditions
- Heat
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 34 participants (actual)
- Lead sponsor
- University of ConnecticutUniversity, hospital or other
- Study start
- 1 Aug 2014 (actual)
- Primary completion
- 31 Mar 2015 (actual)
- Study completion
- 31 Mar 2015 (actual)
- First posted
- 12 Aug 2019 (actual)
- Results
- Posted 27 Feb 2020
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study had three aims:
- To determine the impact of consecutive days of exercise on thermoregulation and cardiovascular strain.
- To determine the efficacy of a hand cooling device to cool individuals throughout a heat acclimation period.
- To assess the maintenance of thermoregulatory and cardiovascular adaptations derived from heat acclimation during a 25-day intermittent exercise-heat exposure protocol.
Detailed description
Participants completed 14 days of exercise heat acclimation in either a hot or cool environment, followed by a heat or cool exercise exposure every 5th day for 25 days. Cardiovascular, thermoregulatory, and perceptual strain were measured throughout exercise each day. Hydration assessment and stress response via blood biomarkers were measured before and after exercise. Aerobic capacity was measured before and after heat acclimation as well as after the intermittent exercise-heat exposure. Hand cooling was implemented periodically during exercise-heat stress visits to determine cooling efficacy before and after heat acclimation.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Exercise in heat group | Experimental | Other: Heat acclimationExercise in a hot environment |
| Exercise in cool group | Placebo comparator | Other: Exercise in a cool environmentExercise in a cool environment |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- no chronic health problems
- no previous history of exertional heat stroke within the past 3 years
- no history of cardiovascular, metabolic or respiratory disease
- no current musculoskeletal injury that limits physical activity
Key exclusion criteria (3 listed)
- women
- exercise less than once per week
- VO2max < 45 ml/kg/min
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 acclimation14 days of aerobic exercise in a hot environment | Other | Exercise in heat group |
| Exercise in a cool environment14 days of aerobic exercise in a cool environment | Other | Exercise in cool group |
Primary outcome
Internal Body Temperature
Time frame: 5 days
Rectal temperature was assessed five days following measurement at baseline.
1 secondary outcome
Heart Rate
Time frame: 5 days
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Feb 2020.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 33846088Pryor RR, Pryor JL, Vandermark LW, Adams EL, Brodeur RM, Armstrong LE, Lee EC, Maresh CM, Casa DJ. Short term heat acclimation reduces heat strain during a first, but not second, consecutive exercise-heat exposure. J Sci Med Sport. 2021 Aug;24(8):768-773. doi: 10.1016/j.jsams.2021.03.020. Epub 2021 Apr 6.
- Individual participant dataSharing planned: No. Aggregate data can be shared upon request.
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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.
Douglas J Casa, PhD principal investigator
University of Connecticut
Questions about this trial
What is this clinical trial studying?
A study testing Heat acclimation and Exercise in a cool environment in people with Heat, run by University of Connecticut.
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 4 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 27 Feb 2020. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. 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?
Yes. Results are posted in the registry (first posted 27 Feb 2020). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
Internal Body Temperature (time frame: 5 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04053465, which also lists 1 linked publication.
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 27 Feb 2020.