Intermittent HypoxiaENDUR-HYPOXNCT06714435
Effect of Intermittent Hypoxia on Ventilatory Endurance in Healthy Volunteers
A study testing Intermittent hypoxia and Normoxia in people with Intermittent Hypoxia and Respiratory Endurance, run by Poitiers University Hospital at 1 site in France.
Trial summary
Sleep apnoea syndrome is a common disorder responsible for poor sleep quality and repeated oxygen depletion in the blood. Patients suffering from this disease experience a reduction in their endurance, i.e. their ability to make prolonged efforts. This loss of muscular endurance affects breathing in particular. Read more about this study
- Who is it for?
- Ages 25 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Intermittent Hypoxia, Respiratory Endurance
- What is being tested?
- Intermittent hypoxia and Normoxia
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 28 participants
- Where
- 1 siteFrance
- Study dates
- 16 Jan 2025to 14 Oct 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 25 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Non-excessive coffee drinker (< 3 espressos / day)
- Non-smoker or weaned for 3 months and total consumption < 10 packs/year
- With a BMI within ]18 - 25[ kg/m².
- Benefiting from a Social Security plan or benefiting from one through a third party
- Giving free, informed and signed consent, after receiving clear and fair information about the study.
- Non-inclusion Criteria:
Show all 26Show fewer
- History of respiratory or ENT disease (asthma, chronic bronchitis, COPD, respiratory allergy, swallowing disorders, oropharyngeal malformation, obstructive or central sleep apnea-hypopnea syndrome, alveolar hypoventilation syndrome)
- Respiratory, cardiovascular, muscular, neurological or diabetic pathology or disorders
- Raynaud's disease/syndrome
- History of epilepsy or history of malaise suggestive of epilepsy
- Psychiatric history requiring hospitalization
- Liver failure
- Renal insufficiency
- History of acute mountain sickness (presence during or after a stay at altitude of symptoms of vertigo, headache, nausea/vomiting and incapacitating fatigue: Lake Louise score > 0)
- History of migraines
- Taking medications that interfere with respiratory function or cardiovascular function, or psychotropic drugs ( anxiolytic, sedative, antidepressant, neuroleptic, muscle relaxant, etc.).
- Alcohol or drug dependence
- Anemia, sickle-cell anemia
- SpO2 < 97% at rest in room air
- Currently participating in another clinical study
- Protected persons within the meaning of article L1121-5 to 8 (persons benefiting from enhanced protection, i.e. minors, persons deprived of their liberty by a judicial or administrative decision, pregnant or breast-feeding women, persons staying in a health or social establishment, adults under legal protection, and patients in emergency situations). - Women with childbearing capacity who do not have effective contraception (hormonal/mechanical: oral, injectable, transcutaneous, implantable, intrauterine device, or surgical: tubal ligation, hysterectomy, total oophorectomy).
- Incidental finding of acute mountain sickness (Lake Louise score >0)
- Pregnant woman (incidental finding)
- Persistence of average sleep time < 6h
- Non-reversible deterioration in volunteer's state of health within study period
- Electroencephalogram signal unusable
Who cannot join
None listed.
Trial locations and contacts
1 site in 1 country.
About this study
Sleep apnoea syndrome is a common disorder responsible for poor sleep quality and repeated oxygen depletion in the blood. Patients suffering from this disease experience a reduction in their endurance, i.e. their ability to make prolonged efforts. This loss of muscular endurance affects breathing in particular. It is known that poor sleep reduces endurance, but it is not knwon whether the repeated lack of oxygen for several hours at night also has this effect. This information could help improve the management of certain acute respiratory illnesses (asthma attacks, respiratory infections, etc.).
This project therefore seeks to establish a link between repeated oxygen deprivation and a reduction in the human brain's ability to train respiratory muscles. To this end, the healthy volunteers in this study will perform the same breathing exercise (breathing for as long as possible through a mask that makes inspiration difficult) twice: once after 6 hours' exposure to repeated oxygen deprivation, and once under conditions of normal oxygenation. The order of these exercises will be randomized. These exercises will take place in a special room, a hypoxia chamber, where it is possible to deplete the air breathed in oxygen.
- Conditions
- Intermittent Hypoxia, Respiratory Endurance
- Being tested
- Intermittent hypoxia, Normoxia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Intermittent hypoxiaOther
Intermittent hypoxia during 6 hours in daytime
NormoxiaOther
Normoxia during 6 hours in daytime
| Study group | Role | What they receive |
|---|---|---|
| Groupe 1 | Experimental | Control visit in normoxia at V1 and then test visit in intermittent hypoxia at V2 Receives: Other: Intermittent hypoxia; Other: Normoxia |
| Groupe 2 | Experimental | Test visit in intermittent hypoxia at V1 and then control visit in normoxia at V2 Receives: Other: Intermittent hypoxia; Other: Normoxia |
What is being measured
The primary outcome is the main question the study is designed to answer.
To compare the inspiratory endurance of healthy volunteers after 6h of continuous breathing in room air and after 6h of continuous exposure to intermittent hypoxia in a hypoxic chamber.
Measured: through study completion, an average of 2 years
Secondary outcomes (8)
After 6 h of continuous breathing in room air and after 6 h of continuous exposure to intermittent hypoxia in a hypoxic chamber, compare Maximum Inspiratory Pressure (PImax) before and after the inspiratory endurance test.
Measured: through study completion, an average of 2 years
Compare inspiratory cortical control measured by EEG over the first 15 and last 15 minutes of the inspiratory endurance test after 6 h of continuous breathing in room air and after 6 h of continuous exposure to intermittent hypoxia in a hypoxic chamber.
The inspiratory cortical control is recorded by electroencephalography to measure the amplitude of inspiratory premotor potentials in µV
Measured: through study completion, an average of 2 years
Compare respiratory discomfort with a visual analog scale at the start of the endurance test after 6 h of continuous breathing in room air and after 6 h of continuous exposure to intermittent hypoxia in a hypoxic chamber.
The visual analogue scale ranges from 0 to 10, with 10 being the most severe discomfort
Measured: through study completion, an average of 2 years
Compare the time to onset of respiratory discomfort in the inspiratory endurance test with a visual analog scale after 6 h of continuous breathing in room air and after 6 h of continuous exposure to intermittent hypoxia in a hypoxic chamber.
The visual analogue scale ranges from 0 to 10, with 10 being the most severe discomfort. The time to onset of respiratory discomfort is defined by the time it takes to reach 80% of the maximum discomfort declared by the volunteer.
Measured: through study completion, an average of 2 years
Compare sensory perception of inspiratory effort after 6 h of continuous breathing in room air and after 6 h of continuous exposure to intermittent hypoxia in a hypoxic chamber.
Measured: through study completion, an average of 2 years
Compare the quantity and phenotype of circulating microvesicles in ambient air or in intermittent hypoxia.
Measured: through study completion, an average of 2 years
Compare systolic pulmonary artery pressure in room air or intermittent hypoxia using trans-thoracic echography.
The systolic pulmonary artery pressure is measured by the following measurements :
- The maximum regurgitation velocity of tricuspid insufficiency will be measured by continuous Doppler in order to estimate the pressure gradient between the right atrium and the pulmonary artery using Bernoulli's equation.
- The pressure in the right atrium will be estimated by measuring the diameter of the inferior vena cava and its compliance.
Measured: through study completion, an average of 2 years
Compare echographic signs of right ventricular function in room air or intermittent hypoxia using trans-thoracic echography.
Right ventricular function is estimated by measuring the tricuspid annular plane systolic excursion (TAPSE) and the S wave.
Measured: through study completion, an average of 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Dec 2024
- Study start16 Jan 2025
- Primary completion14 Oct 2025
- Study completion14 Oct 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Intermittent HypoxiaStudies of the same condition, open and under way.
- More trials run by Poitiers University HospitalThe sponsor's other registered studies.
- 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
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 28 participants (actual)
Sponsor and investigators
- Lead sponsor
- Poitiers University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Céline ABONNEAU, Study chair, CHU Poitiers
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06714435
- Sponsor's protocol ID
- ENDUR-HYPOX
- Acronym
- ENDUR-HYPOX
- Status last verified
- Oct 2025
- First submitted
- 25 Nov 2024
- Last updated
- 9 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Intermittent Hypoxia on Ventilatory Endurance in Healthy Volunteers
- ClinicalTrials.gov ID
- NCT06714435
- Acronym / sponsor ID
- ENDUR-HYPOX / ENDUR-HYPOX
- Conditions
- Intermittent Hypoxia, Respiratory Endurance
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 28 participants (actual)
- Lead sponsor
- Poitiers University HospitalUniversity, hospital or other
- Study start
- 16 Jan 2025 (actual)
- Primary completion
- 14 Oct 2025 (actual)
- Study completion
- 14 Oct 2025 (actual)
- First posted
- 3 Dec 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.
Sleep apnoea syndrome is a common disorder responsible for poor sleep quality and repeated oxygen depletion in the blood. Patients suffering from this disease experience a reduction in their endurance, i.e. their ability to make prolonged efforts. This loss of muscular endurance affects breathing in particular. It is known that poor sleep reduces endurance, but it is not knwon whether the repeated lack of oxygen for several hours at night also has this effect. This information could help improve the management of certain acute respiratory illnesses (asthma attacks, respiratory infections, etc.).
This project therefore seeks to establish a link between repeated oxygen deprivation and a reduction in the human brain's ability to train respiratory muscles. To this end, the healthy volunteers in this study will perform the same breathing exercise (breathing for as long as possible through a mask that makes inspiration difficult) twice: once after 6 hours' exposure to repeated oxygen deprivation, and once under conditions of normal oxygenation. The order of these exercises will be randomized. These exercises will take place in a special room, a hypoxia chamber, where it is possible to deplete the air breathed in oxygen.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Groupe 1 | Experimental | Other: Intermittent hypoxia, Other: NormoxiaControl visit in normoxia at V1 and then test visit in intermittent hypoxia at V2 |
| Groupe 2 | Experimental | Other: Intermittent hypoxia, Other: NormoxiaTest visit in intermittent hypoxia at V1 and then control visit in normoxia at V2 |
Who may qualify
- Ages
- 25 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (26 listed)
- Non-excessive coffee drinker (< 3 espressos / day)
- Non-smoker or weaned for 3 months and total consumption < 10 packs/year
- With a BMI within ]18 - 25[ kg/m².
- Benefiting from a Social Security plan or benefiting from one through a third party
- Giving free, informed and signed consent, after receiving clear and fair information about the study.
Key exclusion criteria (0 listed)
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 |
|---|---|---|
| Intermittent hypoxiaIntermittent hypoxia during 6 hours in daytime | Other | Groupe 1, Groupe 2 |
| NormoxiaNormoxia during 6 hours in daytime | Other | Groupe 1, Groupe 2 |
Primary outcome
To compare the inspiratory endurance of healthy volunteers after 6h of continuous breathing in room air and after 6h of continuous exposure to intermittent hypoxia in a hypoxic chamber.
Time frame: through study completion, an average of 2 years
8 secondary outcomes
After 6 h of continuous breathing in room air and after 6 h of continuous exposure to intermittent hypoxia in a hypoxic chamber, compare Maximum Inspiratory Pressure (PImax) before and after the inspiratory endurance test.
Time frame: through study completion, an average of 2 years
Compare inspiratory cortical control measured by EEG over the first 15 and last 15 minutes of the inspiratory endurance test after 6 h of continuous breathing in room air and after 6 h of continuous exposure to intermittent hypoxia in a hypoxic chamber.
Time frame: through study completion, an average of 2 years
Compare respiratory discomfort with a visual analog scale at the start of the endurance test after 6 h of continuous breathing in room air and after 6 h of continuous exposure to intermittent hypoxia in a hypoxic chamber.
Time frame: through study completion, an average of 2 years
Compare the time to onset of respiratory discomfort in the inspiratory endurance test with a visual analog scale after 6 h of continuous breathing in room air and after 6 h of continuous exposure to intermittent hypoxia in a hypoxic chamber.
Time frame: through study completion, an average of 2 years
Compare sensory perception of inspiratory effort after 6 h of continuous breathing in room air and after 6 h of continuous exposure to intermittent hypoxia in a hypoxic chamber.
Time frame: through study completion, an average of 2 years
Compare the quantity and phenotype of circulating microvesicles in ambient air or in intermittent hypoxia.
Time frame: through study completion, an average of 2 years
Compare systolic pulmonary artery pressure in room air or intermittent hypoxia using trans-thoracic echography.
Time frame: through study completion, an average of 2 years
Compare echographic signs of right ventricular function in room air or intermittent hypoxia using trans-thoracic echography.
Time frame: through study completion, an average of 2 years
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 9 Jun 2026.
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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.
Céline ABONNEAU study chair
CHU Poitiers
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Intermittent hypoxia and Normoxia in people with Intermittent Hypoxia and Respiratory Endurance, run by Poitiers University Hospital at 1 site in France.
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 26 inclusion and 0 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 9 Jun 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 France. 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?
To compare the inspiratory endurance of healthy volunteers after 6h of continuous breathing in room air and after 6h of continuous exposure to intermittent hypoxia in a hypoxic chamber. (time frame: through study completion, an average of 2 years). 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 9 Jun 2026.