Obesity & OverweightHYPOXFATNCT07796971
High-Intensity Interval Training in Low Versus Normal Oxygen: Effects on Body Fat and Gut Health in Adults Aged 50-75 With Overweight or Obesity (HYPOXFAT)
A study testing Hypoxic High-Intensity Interval Training and Normoxic High-Intensity Interval Training in people with Obesity & Overweight and Fat Mass, run by Laboratoire des Adaptations Métaboliques à l'Exercice en conditions Physiologiques et Pathologiques at 1 site in France.
Trial summary
Overweight and obesity are major public health challenges worldwide, and their prevalence increases with age, partly because of age-related metabolic and hormonal changes. Beyond total fat mass, abdominal and particularly visceral fat accumulation is strongly associated with chronic low-grade inflammation, insulin… Read more about this study
- Who is it for?
- Ages 50 to 75 years
- Conditions the study is for
- Obesity & Overweight, Fat Mass
- What is being tested?
- Hypoxic High-Intensity Interval Training and Normoxic High-Intensity Interval Training
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 32 participants
- Where
- 1 siteFrance
- Study dates
- 26 Aug 2026to 5 Jul 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 50 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Aged 50-75 years, inclusive Male or postmenopausal female, defined as no menstruation during the previous 12 months Body mass index between 25 and 35 kg/m², inclusive Non-smoker or smoking no more than two cigarettes per day Stable body weight for at least three months before study initiation, defined as a change of less than 4 kg Stable dietary habits and physical activity level for at least three months before study initiation Willing to maintain usual dietary habits and physical activity level throughout the study Able and willing to comply with the study protocol Able and willing to provide written informed consent Affiliated with a social security scheme Willing to be registered in the French National Register of Volunteers Participating in Biomedical Research
Who cannot join
- Medical or surgical history considered by the investigators to be incompatible with participation in the study Any medical condition considered by the investigators to be incompatible with participation in the study Medical contraindication to vigorous physical activity Current use of hormone replacement therapy Current use of beta-blocker therapy Diagnosed moderate-to-severe sleep apnoea syndrome that is untreated or inadequately controlled High-risk cardiovascular history, including symptomatic coronary artery disease, recent myocardial infarction or stroke, unstable heart failure, clinically significant arrhythmia, or uncontrolled hypertension Severe respiratory disease, including advanced chronic obstructive pulmonary disease classified as group B or E according to the 2023 GOLD classification, chronic respiratory failure, or uncontrolled asthma Diabetes of any type Chronic kidney disease stage 3B, 4 or 5 according to the KDIGO classification Severe liver disease, defined by an international normalised ratio greater than 1.2-1.3 Antibiotic treatment during the three months preceding the first stool collection More than eight hours of moderate-to-vigorous physical activity per week Any treatment that, in the investigators' opinion, could interfere with assessment of the study outcomes Low-energy diet during the three months preceding the study or intention to begin an energy-restricted diet during the study Extreme dietary habits Stay at an altitude above 2,500 m for more than eight days during the three months preceding the study Participation in another clinical study or currently within an exclusion period following participation in a previous clinical study Total compensation received for participation in research since the beginning of the calendar year exceeding €4,500, or the applicable regulatory limit Linguistic or psychological inability to provide informed consent Refusal to provide written informed consent Legally protected adult Deprived of liberty by an administrative or judicial decision Under guardianship or curatorship
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site, 1 recruiting
- Recruiting
CREPS Auvergne Rhône-Alpes / Vichy
Bellerive-sur-Allier, 03321
Nathalie BOISSEAU, Pr, 0473405519 ext. +33, nathalie.boisseau@uca.fr
About this study
Official title: High-intensity Interval Training Under Hypoxic Versus Normoxic Conditions: Effects on Fat Mass Loss and Gut Microbiota in Adults Aged 50-75 With Overweight or Obesity
Overweight and obesity are major public health challenges worldwide, and their prevalence increases with age, partly because of age-related metabolic and hormonal changes. Beyond total fat mass, abdominal and particularly visceral fat accumulation is strongly associated with chronic low-grade inflammation, insulin resistance, hypertension and cardiovascular disease. Men are more likely to display an android fat distribution, while premenopausal women generally show a more protective gynoid distribution. However, declining sex hormone concentrations after menopause promote abdominal and visceral fat accumulation, increasing cardiometabolic risk.
Physical activity is a cornerstone of overweight and obesity management. High-intensity interval training (HIIT) is an effective strategy for reducing total, abdominal and visceral fat and may produce greater benefits than moderate-intensity continuous training. Since 2016, our team has conducted several studies and reviews showing that HIIT performed on a cycle ergometer or treadmill, alone or combined with resistance training, reduces total and abdominal fat mass in people with overweight or obesity, regardless of age, sex or hormonal status.
Read more
HIIT can also be performed under real or simulated hypoxic conditions to enhance cardiovascular, respiratory, circulatory, haematological and skeletal muscle adaptations. The Live Low-Train High model allows participants to live under normoxic conditions while being exposed to hypoxia only during exercise. Hypoxic HIIT has proved feasible and safe in people with metabolic disorders or physical deconditioning, including at simulated altitudes of 4,000-5,000 m. However, only two studies have suggested that hypoxic HIIT may enhance fat mass loss in people with overweight or obesity. Neither specifically assessed abdominal or visceral fat, and neither focused on postmenopausal women.
Several mechanisms may contribute to HIIT-induced fat loss, including increased catecholaminergic stimulation and lipid oxidation during recovery, excess post-exercise oxygen consumption and changes in appetite regulation. The gut microbiota may also contribute to the regulation of adipose tissue and cardiometabolic health. Physical activity can increase bacterial diversity and promote beneficial taxa, particularly short-chain fatty acid-producing bacteria. Our previous HIIT studies identified associations between changes in selected bacteria and reductions in total or abdominal fat mass. Hypoxic exposure may also alter gut microbiota composition and abundance, with effects depending on the severity and type of hypoxia.
This study will assess the effects of a 3-month cycle-ergometer HIIT programme, performed three times per week under hypoxic versus normoxic conditions, in adults aged 50-75 years with overweight or obesity. The primary objective is to determine whether hypoxic HIIT produces a greater reduction in abdominal and visceral fat mass than the same training performed in normoxia.
Secondary outcomes will include total and regional fat and lean mass; fasting glucose, insulin, HbA1c and HOMA-IR; total cholesterol, triglycerides, HDL-C, LDL-C, ApoB, ApoA1 and the ApoB/ApoA1 ratio; high-sensitivity C-reactive protein and fibrinogen; systolic and diastolic blood pressure; blood biophysical properties; and faecal microbiota richness, diversity and taxonomic composition. Lipid oxidation during prolonged moderate-intensity exercise, maximal oxygen uptake and maximal aerobic power will also be assessed before and after the intervention.
We hypothesise that hypoxic training will enhance improvements in body composition, metabolic and cardiovascular risk factors, aerobic fitness and lipid oxidation compared with normoxic training. We further hypothesise that hypoxia will modify faecal microbiota composition and that changes in selected bacterial taxa will be associated with changes in body composition and cardiovascular risk markers.
The ultimate aim is to improve the management of adults aged 50-75 years with overweight or obesity by developing an effective 3-month HIIT programme performed under controlled hypoxic conditions.
- Conditions
- Obesity & Overweight, Fat Mass
- Being tested
- Hypoxic High-Intensity Interval Training, Normoxic High-Intensity Interval Training
- Keywords
- HIIT, normobaric hypoxia, fat mass, health, overweight, obesity, exercise prescription
- Medical subject headings
- Obesity, Overweight
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hypoxic High-Intensity Interval TrainingBehavioural
Also called Hypoxic HIIT, HIIT-H
Participants will complete 36 cycle-ergometer HIIT sessions over 12 weeks (three sessions per week) under normobaric hypoxia (FiO₂: 15%; simulated altitude: 3,000 m). Each session will include a 5-minute warm-up followed by 60 repetitions of 8 seconds of acceleration at approximately 80-85 rpm and 12 seconds of deceleration at approximately 60 rpm. The 8-second efforts will be performed at 75-80% of maximal aerobic power.
Normoxic High-Intensity Interval TrainingBehavioural
Also called Normoxic HIIT, HIIT-N
Participants will complete 36 cycle-ergometer HIIT sessions over 12 weeks (three sessions per week) under normoxic conditions (FiO₂: 21%). Each session will include a 5-minute warm-up followed by 60 repetitions of 8 seconds of acceleration at approximately 80-85 rpm and 12 seconds of deceleration at approximately 60 rpm. The 8-second efforts will be performed at 75-80% of maximal aerobic power.
| Study group | Role | What they receive |
|---|---|---|
| Hypoxic HIIT (HIIT-H) | Experimental | Participants will complete a 12-week cycle-ergometer HIIT programme, with three sessions per week, under normobaric hypoxia (FiO₂: 15%; simulated altitude: 3,000 m). Receives: Behavioral: Hypoxic High-Intensity Interval Training |
| Normoxic HIIT (HIIT-N) | Active comparator | Participants will complete the same 12-week cycle-ergometer HIIT programme, with three sessions per week, under normoxic conditions (FiO₂: 21%). Receives: Behavioral: Normoxic High-Intensity Interval Training |
What is being measured
The primary outcome is the main question the study is designed to answer.
Relative Change in Total Abdominal Fat Mass
Total abdominal fat mass will be measured by dual-energy X-ray absorptiometry (DXA) at baseline and after the 12-week intervention. The relative change will be calculated as: (abdominal fat mass at 12 weeks - abdominal fat mass at baseline) / abdominal fat mass at baseline. More negative values indicate a greater reduction in abdominal fat mass. The change will be compared between the hypoxic and normoxic HIIT groups.
Measured: Baseline and immediately after the 12-week intervention
Secondary outcomes (14)
Relative Change in Body Mass
Description: Body mass will be measured in kilograms at baseline and after the 12-week intervention. Relative change will be calculated as: (week 12 value - baseline value) / baseline value and compared between the hypoxic and normoxic HIIT groups.
Measured: Baseline and after 12 weeks of intervention
Relative Change in Visceral Abdominal Fat Mass
Description: Visceral abdominal fat mass will be measured by DXA at baseline and after the 12-week intervention. Relative change will be calculated as: (week 12 value - baseline value) / baseline value and compared between groups.
Measured: Baseline and after 12 weeks of intervention
Relative Change in Total Lean Mass
Description: Total lean mass will be measured in kilograms by DXA at baseline and after the 12-week intervention. Relative change will be calculated as: (week 12 value - baseline value) / baseline value and compared between groups.
Measured: Baseline and after 12 weeks of intervention
Relative Change in Waist-to-Hip Ratio
Description: The waist-to-hip ratio will be calculated by dividing waist circumference by hip circumference at baseline and after the 12-week intervention. Relative change will be calculated as: (week 12 value - baseline value) / baseline value and compared between groups.
Measured: Baseline and after 12 weeks of intervention
Relative Change in metabolic Plasma parameters (TG, HBA1C, glucose, insulin, HDL, LDL)
Fasting concentration will be measured at baseline and after the 12-week intervention. Relative change will be calculated as: (week 12 value - baseline value) / baseline value and compared between groups.
Measured: Baseline and after 12 weeks of intervention
Relative Change in Whole Blood Viscosity
Whole blood viscosity will be assessed using standardised haemorheological procedures at baseline and after the 12-week intervention. Relative change will be calculated as: (week 12 value - baseline value) / baseline value and compared between groups.
Measured: Baseline and after 12 weeks of intervention
Relative Change in Red Blood Cell Deformability
Description: Red blood cell deformability will be assessed using standardised haemorheological procedures at baseline and after the 12-week intervention. Relative change will be calculated as: (week 12 value - baseline value) / baseline value and compared between groups.
Measured: Baseline and after 12 weeks of intervention
Relative Change in Red Blood Cell Aggregation
Description: Red blood cell aggregation will be assessed using standardised haemorheological procedures at baseline and after the 12-week intervention. Relative change will be calculated as: (week 12 value - baseline value) / baseline value and compared between groups.
Measured: Baseline and after 12 weeks of intervention
Change in the Relative Abundance of Prespecified Gut Bacterial Taxa
Description: The relative abundance of prespecified bacterial taxa will be determined from faecal microbiota samples collected at baseline and after the 12-week intervention. Changes in relative abundance will be compared between the hypoxic and normoxic HIIT groups.
Measured: Baseline and after 12 weeks of intervention
Change in Faecal Gut Microbiota Alpha Diversity
Description: Alpha-diversity indices reflecting within-sample bacterial richness and diversity will be calculated from faecal microbiota samples collected at baseline and after the 12-week intervention. Changes will be compared between the hypoxic and normoxic HIIT groups.
Measured: Baseline and after 12 weeks of intervention
Change in Faecal Gut Microbiota Beta Diversity
Description: Beta diversity, reflecting differences in bacterial community composition, will be assessed using faecal samples collected at baseline and after the 12-week intervention. Changes in community composition will be compared between the hypoxic and normoxic HIIT groups.
Measured: Baseline and after 12 weeks of intervention
Relative Change in Maximal Aerobic Power
Description: Maximal aerobic power, expressed in watts, will be determined during a maximal exercise test at baseline and after the 12-week intervention. Relative change will be calculated as: (week 12 value - baseline value) / baseline value and compared between groups.
Measured: Baseline and after 12 weeks of intervention
Relative Change in Lipid Oxidation Rate During Submaximal Exercise
Description: Lipid oxidation rate, expressed in grams per minute, will be calculated by indirect calorimetry during 45 minutes of fasted exercise performed at 50% of V̇O₂max, at baseline and after the 12-week intervention. Relative change will be calculated as: (week 12 value - baseline value) / baseline value and compared between groups.
Measured: Baseline and after 12 weeks of intervention
Relative Change in Carbohydrate Oxidation Rate During Submaximal Exercise
Description: Carbohydrate oxidation rate, expressed in grams per minute, will be calculated by indirect calorimetry during 45 minutes of fasted exercise performed at 50% of V̇O₂max, at baseline and after the 12-week intervention. Relative change will be calculated as: (week 12 value - baseline value) / baseline value and compared between groups.
Measured: Baseline and after 12 weeks of intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Sep 2026
- Study start26 Aug 2026
- Primary completion5 Jul 2028 (estimated)
- Study completion5 Jul 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obesity & OverweightStudies 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
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- A randomised, controlled, single-centre, parallel-group study comparing 12 weeks of cycle-ergometer HIIT performed under normobaric hypoxia (FiO₂: 15%; simulated altitude: 3,000 m) with the same training programme performed under normoxia (FiO₂: 21%). Participants are allocated to one of two groups, stratified by sex, and remain in the assigned group throughout the intervention.
- Masking
- None (open label)
- Enrolment
- 32 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Laboratoire des Adaptations Métaboliques à l'Exercice en conditions Physiologiques et Pathologiques
- Sponsor type
- University, hospital or other
- Collaborators
- CREPS Auvergne Rhône-Alpes (AURA)
- Responsible party
- Principal investigator, BOISSEAU Nathalie, Laboratoire des Adaptations Métaboliques à l'Exercice en conditions Physiologiques et Pathologiques
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07796971
- Sponsor's protocol ID
- ID-RCB : 2025-A01744-45
- Acronym
- HYPOXFAT
- Status last verified
- Aug 2026
- First submitted
- 27 Aug 2026
- Last updated
- 1 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- High-intensity Interval Training Under Hypoxic Versus Normoxic Conditions: Effects on Fat Mass Loss and Gut Microbiota in Adults Aged 50-75 With Overweight or Obesity
- ClinicalTrials.gov ID
- NCT07796971
- Acronym / sponsor ID
- HYPOXFAT / ID-RCB : 2025-A01744-45
- Conditions
- Obesity & Overweight, Fat Mass
- Keywords
- HIIT, normobaric hypoxia, fat mass, health, overweight, obesity, exercise prescription
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 32 participants (estimated)
- Lead sponsor
- Laboratoire des Adaptations Métaboliques à l'Exercice en conditions Physiologiques et PathologiquesUniversity, hospital or other
- Collaborators
- CREPS Auvergne Rhône-Alpes (AURA)
- Study start
- 26 Aug 2026 (actual)
- Primary completion
- 5 Jul 2028 (estimated)
- Study completion
- 5 Jul 2028 (estimated)
- First posted
- 1 Sep 2026 (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.
Overweight and obesity are major public health challenges worldwide, and their prevalence increases with age, partly because of age-related metabolic and hormonal changes. Beyond total fat mass, abdominal and particularly visceral fat accumulation is strongly associated with chronic low-grade inflammation, insulin resistance, hypertension and cardiovascular disease. Men are more likely to display an android fat distribution, while premenopausal women generally show a more protective gynoid distribution. However, declining sex hormone concentrations after menopause promote abdominal and visceral fat accumulation, increasing cardiometabolic risk.
Physical activity is a cornerstone of overweight and obesity management. High-intensity interval training (HIIT) is an effective strategy for reducing total, abdominal and visceral fat and may produce greater benefits than moderate-intensity continuous training. Since 2016, our team has conducted several studies and reviews showing that HIIT performed on a cycle ergometer or treadmill, alone or combined with resistance training, reduces total and abdominal fat mass in people with overweight or obesity, regardless of age, sex or hormonal status.
HIIT can also be performed under real or simulated hypoxic conditions to enhance cardiovascular, respiratory, circulatory, haematological and skeletal muscle adaptations. The Live Low-Train High model allows participants to live under normoxic conditions while being exposed to hypoxia only during exercise. Hypoxic HIIT has proved feasible and safe in people with metabolic disorders or physical deconditioning, including at simulated altitudes of 4,000-5,000 m. However, only two studies have suggested that hypoxic HIIT may enhance fat mass loss in people with overweight or obesity. Neither specifically assessed abdominal or visceral fat, and neither focused on postmenopausal women.
Several mechanisms may contribute to HIIT-induced fat loss, including increased catecholaminergic stimulation and lipid oxidation during recovery, excess post-exercise oxygen consumption and changes in appetite regulation. The gut microbiota may also contribute to the regulation of adipose tissue and cardiometabolic health. Physical activity can increase bacterial diversity and promote beneficial taxa, particularly short-chain fatty acid-producing bacteria. Our previous HIIT studies identified associations between changes in selected bacteria and reductions in total or abdominal fat mass. Hypoxic exposure may also alter gut microbiota composition and abundance, with effects depending on the severity and type of hypoxia.
This study will assess the effects of a 3-month cycle-ergometer HIIT programme, performed three times per week under hypoxic versus normoxic conditions, in adults aged 50-75 years with overweight or obesity. The primary objective is to determine whether hypoxic HIIT produces a greater reduction in abdominal and visceral fat mass than the same training performed in normoxia.
Secondary outcomes will include total and regional fat and lean mass; fasting glucose, insulin, HbA1c and HOMA-IR; total cholesterol, triglycerides, HDL-C, LDL-C, ApoB, ApoA1 and the ApoB/ApoA1 ratio; high-sensitivity C-reactive protein and fibrinogen; systolic and diastolic blood pressure; blood biophysical properties; and faecal microbiota richness, diversity and taxonomic composition. Lipid oxidation during prolonged moderate-intensity exercise, maximal oxygen uptake and maximal aerobic power will also be assessed before and after the intervention.
We hypothesise that hypoxic training will enhance improvements in body composition, metabolic and cardiovascular risk factors, aerobic fitness and lipid oxidation compared with normoxic training. We further hypothesise that hypoxia will modify faecal microbiota composition and that changes in selected bacterial taxa will be associated with changes in body composition and cardiovascular risk markers.
The ultimate aim is to improve the management of adults aged 50-75 years with overweight or obesity by developing an effective 3-month HIIT programme performed under controlled hypoxic conditions.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- A randomised, controlled, single-centre, parallel-group study comparing 12 weeks of cycle-ergometer HIIT performed under normobaric hypoxia (FiO₂: 15%; simulated altitude: 3,000 m) with the same training programme performed under normoxia (FiO₂: 21%). Participants are allocated to one of two groups, stratified by sex, and remain in the assigned group throughout the intervention.
| Arm | Type | Receives |
|---|---|---|
| Hypoxic HIIT (HIIT-H) | Experimental | Behavioral: Hypoxic High-Intensity Interval TrainingParticipants will complete a 12-week cycle-ergometer HIIT programme, with three sessions per week, under normobaric hypoxia (FiO₂: 15%; simulated altitude: 3,000 m). |
| Normoxic HIIT (HIIT-N) | Active comparator | Behavioral: Normoxic High-Intensity Interval TrainingParticipants will complete the same 12-week cycle-ergometer HIIT programme, with three sessions per week, under normoxic conditions (FiO₂: 21%). |
Who may qualify
- Ages
- 50 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Aged 50-75 years, inclusive Male or postmenopausal female, defined as no menstruation during the previous 12 months Body mass index between 25 and 35 kg/m², inclusive Non-smoker or smoking no more than two cigarettes per day Stable body weight for at least three months before study initiation, defined as a change of less than 4 kg Stable dietary habits and physical activity level for at least three months before study initiation Willing to maintain usual dietary habits and physical activity level throughout the study Able and willing to comply with the study protocol Able and willing to provide written informed consent Affiliated with a social security scheme Willing to be registered in the French National Register of Volunteers Participating in Biomedical Research
Key exclusion criteria (1 listed)
- Medical or surgical history considered by the investigators to be incompatible with participation in the study Any medical condition considered by the investigators to be incompatible with participation in the study Medical contraindication to vigorous physical activity Current use of hormone replacement therapy Current use of beta-blocker therapy Diagnosed moderate-to-severe sleep apnoea syndrome that is untreated or inadequately controlled High-risk cardiovascular history, including symptomatic coronary artery disease, recent myocardial infarction or stroke, unstable heart failure, clinically significant arrhythmia, or uncontrolled hypertension Severe respiratory disease, including advanced chronic obstructive pulmonary disease classified as group B or E according to the 2023 GOLD classification, chronic respiratory failure, or uncontrolled asthma Diabetes of any type Chronic kidney disease stage 3B, 4 or 5 according to the KDIGO classification Severe liver disease, defined by an international normalised ratio greater than 1.2-1.3 Antibiotic treatment during the three months preceding the first stool collection More than eight hours of moderate-to-vigorous physical activity per week Any treatment that, in the investigators' opinion, could interfere with assessment of the study outcomes Low-energy diet during the three months preceding the study or intention to begin an energy-restricted diet during the study Extreme dietary habits Stay at an altitude above 2,500 m for more than eight days during the three months preceding the study Participation in another clinical study or currently within an exclusion period following participation in a previous clinical study Total compensation received for participation in research since the beginning of the calendar year exceeding €4,500, or the applicable regulatory limit Linguistic or psychological inability to provide informed consent Refusal to provide written informed consent Legally protected adult Deprived of liberty by an administrative or judicial decision Under guardianship or curatorship
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 |
|---|---|---|
| Hypoxic High-Intensity Interval TrainingAlso: Hypoxic HIIT, HIIT-HParticipants will complete 36 cycle-ergometer HIIT sessions over 12 weeks (three sessions per week) under normobaric hypoxia (FiO₂: 15%; simulated altitude: 3,000 m). Each session will include a 5-minute warm-up followed by 60 repetitions of 8 seconds of acceleration at approximately 80-85 rpm and 12 seconds of deceleration at approximately 60 rpm. The 8-second efforts will be performed at 75-80% of maximal aerobic power. | Behavioural | Hypoxic HIIT (HIIT-H) |
| Normoxic High-Intensity Interval TrainingAlso: Normoxic HIIT, HIIT-NParticipants will complete 36 cycle-ergometer HIIT sessions over 12 weeks (three sessions per week) under normoxic conditions (FiO₂: 21%). Each session will include a 5-minute warm-up followed by 60 repetitions of 8 seconds of acceleration at approximately 80-85 rpm and 12 seconds of deceleration at approximately 60 rpm. The 8-second efforts will be performed at 75-80% of maximal aerobic power. | Behavioural | Normoxic HIIT (HIIT-N) |
Primary outcome
Relative Change in Total Abdominal Fat Mass
Time frame: Baseline and immediately after the 12-week intervention
Total abdominal fat mass will be measured by dual-energy X-ray absorptiometry (DXA) at baseline and after the 12-week intervention. The relative change will be calculated as: (abdominal fat mass at 12 weeks - abdominal fat mass at baseline) / abdominal fat mass at baseline. More negative values indicate a greater reduction in abdominal fat mass. The change will be compared between the hypoxic and normoxic HIIT groups.
14 secondary outcomes
Relative Change in Body Mass
Time frame: Baseline and after 12 weeks of intervention
Relative Change in Visceral Abdominal Fat Mass
Time frame: Baseline and after 12 weeks of intervention
Relative Change in Total Lean Mass
Time frame: Baseline and after 12 weeks of intervention
Relative Change in Waist-to-Hip Ratio
Time frame: Baseline and after 12 weeks of intervention
Relative Change in metabolic Plasma parameters (TG, HBA1C, glucose, insulin, HDL, LDL)
Time frame: Baseline and after 12 weeks of intervention
Relative Change in Whole Blood Viscosity
Time frame: Baseline and after 12 weeks of intervention
Relative Change in Red Blood Cell Deformability
Time frame: Baseline and after 12 weeks of intervention
Relative Change in Red Blood Cell Aggregation
Time frame: Baseline and after 12 weeks of intervention
Change in the Relative Abundance of Prespecified Gut Bacterial Taxa
Time frame: Baseline and after 12 weeks of intervention
Change in Faecal Gut Microbiota Alpha Diversity
Time frame: Baseline and after 12 weeks of intervention
Change in Faecal Gut Microbiota Beta Diversity
Time frame: Baseline and after 12 weeks of intervention
Relative Change in Maximal Aerobic Power
Time frame: Baseline and after 12 weeks of intervention
Relative Change in Lipid Oxidation Rate During Submaximal Exercise
Time frame: Baseline and after 12 weeks of intervention
Relative Change in Carbohydrate Oxidation Rate During Submaximal Exercise
Time frame: Baseline and after 12 weeks of intervention
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Sep 2026.
- Individual participant dataSharing planned: No
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Hypoxic High-Intensity Interval Training and Normoxic High-Intensity Interval Training in people with Obesity & Overweight and Fat Mass, run by Laboratoire des Adaptations Métaboliques à l'Exercice en conditions Physiologiques et Pathologiques 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 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: looking for participants now, as of the sponsor's last update on 1 Sep 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Nathalie BOISSEAU, Professor (+33684331693, nathalie.boisseau@uca.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Relative Change in Total Abdominal Fat Mass (time frame: Baseline and immediately after the 12-week intervention). 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 Sep 2026.