Intensive SportERUPTION-2NCT05098925
Study of Thermoregulatory Processes in Ultra-endurance Runners in a Hot and Humid Environment
A study testing Biological testing in people with Intensive Sport, run by Centre Hospitalier Universitaire de la Réunion at 1 site in Reunion.
Trial summary
Human beings are characterized by their extraordinary ability to thermoregulate. During a physical exercise, only 20% of the energy provided by the substrates is converted into muscular mechanical work. The remaining 80% is released as heat. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Intensive Sport
- What is being tested?
- Biological testing
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 80 participants
- Where
- 1 siteReunion
- Study dates
- 19 Oct 2021to 31 Dec 2021
- 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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Runners participating in " La diagonale des fous " race of the "Grand Raid" 2021 on Reunion Island
Who cannot join
- Runners who do not understand French
Trial locations and contacts
1 site in 1 country.
About this study
Human beings are characterized by their extraordinary ability to thermoregulate.
During a physical exercise, only 20% of the energy provided by the substrates is converted into muscular mechanical work. The remaining 80% is released as heat. In temperate environments, so-called metabolic heat is dissipated by several physical phenomena (radiation, conduction, convection and evaporation). However, if the dissipation capacity (in a hot and humid environment for example) is lower than the production of metabolic heat, the body temperature increases progressively until exercise stops or heat-related pathologies develop. This pathological entity defined by the acronym EHI for Exertional Heat Illness gather a wide spectrum of clinical forms ranging from oedema or heat rash, to muscle cramps, to syncope; up to more serious forms such as heat exhaustion or heat stroke during exercise.
Read more
Heatstroke during exercise is the second most common cause of death in athletes after heart disease.
However, the results of the epidemiological studies and the recommendations are limited to events with effort durations or distances not exceeding those of the marathon. They therefore do not consider ultra-endurance disciplines.
These disciplines, defined by durations of effort of at least 6 hours, have specific characteristics (duration of effort, intensity, steep gradients, exotic destinations, extreme environments) which means that extrapolation of the results and knowledge of the physiology of thermoregulation from "classic" endurance events, such as marathons, to ultra-endurance events is hazardous. There are therefore significant areas of uncertainty in understanding the thermoregulatory function, prevalence of EHI (Exertional Heat Illness) and health implications of ultra-endurance running in a hot environment. This is the context of ERUPTION-2.
- Conditions
- Intensive Sport
- Being tested
- Biological testing
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Biological testingOther
Blood sampling, microcapillary sampling, temperature monitoring, saliva testing, EHI questionnaire
| Study group | Role | What they receive |
|---|---|---|
| Intervention | Experimental | Study of Thermoregulatory Processes in Ultra-endurance Runners in a Hot and Humid Environment Receives: Other: Biological testing |
What is being measured
The primary outcome is the main question the study is designed to answer.
Core temperature measurement
Measure of core temperature (°C) will be carried out by continuous monitoring using e-Celsius performance Bodycap technology sensors carried by the athletes through the race
Measured: during 3 days of the race
Natremia measurement
Measure of natremia (blood sodium concentration) will be made by 5 measurements carried out on the eve of the start and during the race, by microcapillary blood sample using the i-STAT technology and CHEM8+ cartridges.
Measured: during 3 days of the race
Hydration saliva measurement
Hydration will be measured 5 times carried out on the eve of the start and during the race using saliva sample to measure the salivary osmolarity with the MX3 testing device.
Measured: during 3 days of the race
Hydration by weight measurement
Weight in kg will be measured 5 times carried out on the eve of the start and during the race
Measured: during 3 days of the race
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Oct 2021
- Study start19 Oct 2021
- Primary completion24 Oct 2021
- Study completion31 Dec 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Intensive SportStudies 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
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 80 participants (actual)
Sponsor and investigators
- Lead sponsor
- Centre Hospitalier Universitaire de la Réunion
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Nicolas Bouscaren, MD, Principal investigator, Centre Hospitalier Universitaire de La REUNION
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05098925
- Sponsor's protocol ID
- 2021/CHU/25
- Acronym
- ERUPTION-2
- Status last verified
- Mar 2022
- First submitted
- 15 Sep 2021
- Last updated
- 1 Apr 2022
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Bouscaren N, Berly L, Descombes G, Tounkara B, Lacroix E, Lemarchand B, Racinais S, Millet GY. Thermoregulation and Hydration Dynamics in a 160-km Ultra-Endurance Race in a Tropical Environment: A Field Study on 80 Runners. Sports Med. 2026 Mar;56(3):805-820. doi: 10.1007/s40279-025-02356-6. Epub 2025 Dec 4.
PubMed 41343039
Study at a glance
From the registry record, last updated by the sponsor on 1 Apr 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Study of Thermoregulatory Processes in Ultra-endurance Runners in a Hot and Humid Environment
- ClinicalTrials.gov ID
- NCT05098925
- Acronym / sponsor ID
- ERUPTION-2 / 2021/CHU/25
- Conditions
- Intensive Sport
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 80 participants (actual)
- Lead sponsor
- Centre Hospitalier Universitaire de la RéunionUniversity, hospital or other
- Study start
- 19 Oct 2021 (actual)
- Primary completion
- 24 Oct 2021 (actual)
- Study completion
- 31 Dec 2021 (actual)
- First posted
- 28 Oct 2021 (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.
Human beings are characterized by their extraordinary ability to thermoregulate.
During a physical exercise, only 20% of the energy provided by the substrates is converted into muscular mechanical work. The remaining 80% is released as heat. In temperate environments, so-called metabolic heat is dissipated by several physical phenomena (radiation, conduction, convection and evaporation). However, if the dissipation capacity (in a hot and humid environment for example) is lower than the production of metabolic heat, the body temperature increases progressively until exercise stops or heat-related pathologies develop. This pathological entity defined by the acronym EHI for Exertional Heat Illness gather a wide spectrum of clinical forms ranging from oedema or heat rash, to muscle cramps, to syncope; up to more serious forms such as heat exhaustion or heat stroke during exercise.
Heatstroke during exercise is the second most common cause of death in athletes after heart disease.
However, the results of the epidemiological studies and the recommendations are limited to events with effort durations or distances not exceeding those of the marathon. They therefore do not consider ultra-endurance disciplines.
These disciplines, defined by durations of effort of at least 6 hours, have specific characteristics (duration of effort, intensity, steep gradients, exotic destinations, extreme environments) which means that extrapolation of the results and knowledge of the physiology of thermoregulation from "classic" endurance events, such as marathons, to ultra-endurance events is hazardous. There are therefore significant areas of uncertainty in understanding the thermoregulatory function, prevalence of EHI (Exertional Heat Illness) and health implications of ultra-endurance running in a hot environment. This is the context of ERUPTION-2.
Study design
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Intervention | Experimental | Other: Biological testingStudy of Thermoregulatory Processes in Ultra-endurance Runners in a Hot and Humid Environment |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Runners participating in " La diagonale des fous " race of the "Grand Raid" 2021 on Reunion Island
Key exclusion criteria (1 listed)
- Runners who do not understand French
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 |
|---|---|---|
| Biological testingBlood sampling, microcapillary sampling, temperature monitoring, saliva testing, EHI questionnaire | Other | Intervention |
Primary outcome
Core temperature measurement
Time frame: during 3 days of the race
Measure of core temperature (°C) will be carried out by continuous monitoring using e-Celsius performance Bodycap technology sensors carried by the athletes through the race
Natremia measurement
Time frame: during 3 days of the race
Measure of natremia (blood sodium concentration) will be made by 5 measurements carried out on the eve of the start and during the race, by microcapillary blood sample using the i-STAT technology and CHEM8+ cartridges.
Hydration saliva measurement
Time frame: during 3 days of the race
Hydration will be measured 5 times carried out on the eve of the start and during the race using saliva sample to measure the salivary osmolarity with the MX3 testing device.
Hydration by weight measurement
Time frame: during 3 days of the race
Weight in kg will be measured 5 times carried out on the eve of the start and during the race
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 Apr 2022.
- Derived from this study: PubMed 41343039Bouscaren N, Berly L, Descombes G, Tounkara B, Lacroix E, Lemarchand B, Racinais S, Millet GY. Thermoregulation and Hydration Dynamics in a 160-km Ultra-Endurance Race in a Tropical Environment: A Field Study on 80 Runners. Sports Med. 2026 Mar;56(3):805-820. doi: 10.1007/s40279-025-02356-6. Epub 2025 Dec 4.
- Individual participant dataSharing planned: No
Related trials for Intensive Sport
Not yet recruiting
Towards a Health Promotion for Children Engaged in Sport Intensive Practice for a Healthy Adult
Prevention
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.
Nicolas Bouscaren, MD principal investigator
Centre Hospitalier Universitaire de La REUNION
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Biological testing in people with Intensive Sport, run by Centre Hospitalier Universitaire de la Réunion at 1 site in Reunion.
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 1 inclusion and 1 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 Apr 2022. 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 Reunion. 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?
Core temperature measurement (time frame: during 3 days of the race). The study lists 4 primary outcomes in all. 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 NCT05098925, 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 1 Apr 2022.