Healthy Active AthletesNCT05447416
Intermittent Hypoxic Training (IHT) Versus Hyperbaric Oxygen Therapy (HBOT) for Aerobic Performance
A study testing Hyperbaric Oxygen Therapy - HBOT and Intermittent Hypoxic Training - IHT in people with Healthy Active Athletes, run by Assaf-Harofeh Medical Center at 1 site in Israel.
Trial summary
Comparing the effect of HBOT and IHT on aerobic performance of athletes. Read more about this study
- Who is it for?
- Ages 18 to 45 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Healthy Active Athletes
- What is being tested?
- Hyperbaric Oxygen Therapy - HBOT and Intermittent Hypoxic Training - IHT
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 66 participants
- Where
- 1 siteIsrael
- Study dates
- 1 Jun 2023to 31 Dec 2027
- 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 18 to 45 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Vo2max above 3500 ml or Vo2max/kg above 50 ml/kg
- Age 18-45
- Subjects are active aerobic athletes, training regularly more than 4 exercise sessions per week.
- Subject willing and able to read, understand and sign an informed consent
Who cannot join
- Inability to attend scheduled clinic visits and/or comply with the study protocol
- Active malignancy
- Active smokers
- Previous treatment of HBOT for any reason prior to study enrollment.
- Chest pathology incompatible with pressure changes
- Major orthopedic injury at the past 3 months
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- Inner ear disease
- Lung pathology
- The inability to perform an awake brain MRI
- Claustrophobia
- Previous neurologic conditions (e.g., Epilepsy, Brain tumors or s/p neurosurgery etc.)
- Comorbidities and medications that rule out the subject
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Israel1 site, 1 recruiting
- Recruiting
The Sagol Center for Hyperbaric Medicine and Research Shamir Medical Center (Assaf Harofeh)
Zrifin
Shai Efrati, Prof, 972-8-9779393, efratishai@outlook.com
About this study
Official title: Intermittent Hypoxic Training (IHT) Versus Hyperbaric Oxygen Therapy (HBOT) for Aerobic Performance - Prospective Randomized Study
Comparing the effect of HBOT and IHT on aerobic performance of athletes.
Read the detailed description
Enhanced physical performance is the goal of all professional and non-professional athletes. There are many intervention methods aim to enhance physical performance from 2 intervention related to change in the environment partial oxygen pressure have been demonstrated to have beneficial effect: IHT and HBOT.
This study offers one of the two interventions to athletes with a pre and post intervention objective evaluation of the physiological performance - Maximal exercise test for evaluating VO2MAX and ventilatory thresholds, time to exhaustion, 30 seconds Wingate test, agility test, muscle biopsy, blood tests, brain MRI, cognitive tests and exercise cognitive test.
After signing an informed consent form, eligible subjects will be randomized to one of the study groups at a ratio of 1:1. The IHT group will receive three hypoxic guided training sessions per week, according an individualized training protocol, 24 sessions in total.
The HBOT group will receive 40 daily hyperbaric sessions, five days per week. Each session will include 90 minutes exposure to 100% oxygen at 2ATA with a five-minute air break every 20 minutes. Three times per week, as the IHT group, the HBOT group will have a guided training session, according an individualized training protocol.
Both groups, IHT and HBOT, will have the same relative intensity guided training protocols for 8 weeks, to stimulate the same exercise load. The IHT group will train for 60 minutes, 3 times a week in a normobaric hypoxia environment, at O2 concentration of 15.2% that stimulates a 2500-2600m height. The HBOT group will train for 60 minutes after the HBOT sessions, 3 times per week, in a normobaric normoxic environment
Physical performance evaluations will be conducted on 3 different times post interventions - a day last intervention, 3 weeks after and 2 months after - in order to analyze the long term effect of each intervention.
- Conditions
- Healthy Active Athletes
- Being tested
- Hyperbaric Oxygen Therapy - HBOT, Intermittent Hypoxic Training - IHT
- Keywords
- triathletes, cyclists, mitochondria, HBOT, HBO, IHT
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hyperbaric Oxygen Therapy - HBOTDevice
Each session will include exposure of 90 minutes to 100% at 2 ATA, with 5 minutes air breaks every 20 minutes
Intermittent Hypoxic Training - IHTDevice
Each session lasts 60 minutes of 15.2% oxygen at 1.0 ATA. Subjects will be training according to individualized training protocol.
| Study group | Role | What they receive |
|---|---|---|
| Hyperbaric Oxygen Therapy - HBOT | Active comparator | The protocol comprises of 40 consecutive hyperbaric oxygen treatment (HBOT) sessions, 5 sessions per week within a two months' period. The HBOT group will train for 60 minutes after the HBOT sessions, 3 times per week, in a normobaric normoxic environment according to individualized training protocol Receives: Device: Hyperbaric Oxygen Therapy - HBOT |
| Intermittent Hypoxic Training - IHT | Active comparator | The protocol comprises of 24 consecutive Intermittent Hypoxic Training (IHT) sessions, 3 sessions per week within a two months' period. Subjects will train according to individualized training protocol. Receives: Device: Intermittent Hypoxic Training - IHT |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cardiopulmonary exercise test (CPET)
CPET determines the gas exchange dynamics that is expected to change through the intervention
Measured: Baseline, 11 weeks
Secondary outcomes (8)
Cardiopulmonary exercise test (CPET)
CPET determines the gas exchange dynamics that is expected to change through the intervention
Measured: 8 weeks, 16 weeks
Time To Exhaustion
The test will be conducted on the SRM high performance ergometer on 105% of the maximal aerobic power
Measured: Baseline, 11 weeks, 16 weeks
Wingate 30 seconds anaerobic test
The Wingate Anaerobic Test (WAnT) is conducted on the SRM high performance ergometer.
Measured: Baseline, 11 weeks, 16 weeks
Muscle biopsy for mitochondrial function
Participants will undergo a muscle biopsy, muscle sample will be analyzed using the Oxygraph (Oroboros Inc, Austria) for oxygen respiratory function, as well as staining for mitochondrial proteins
Measured: Baseline, 11 weeks
Blood test for evaluation of CBC
complete blood count
Measured: Baseline, 11 weeks, 16 weeks
Blood test for evaluation of HIF-1α
Hypoxic inducible factor 1α levels
Measured: Baseline, 7 weeks, 8 weeks, 11 weeks, 16 weeks
Blood test for evaluation of Telomeres length
Using staining and FACS technology telomere length will be analyzed
Measured: Baseline,11 weeks, 16 weeks
Blood test for evaluation of mitochondrial function
Mitochondrial function of Peripheral Blood Mononuclear Cells (PBMC) and Platelets (PLT)
Measured: Baseline,11 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Jul 2022
- Study start1 Jun 2023
- Primary completion31 Aug 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy Active AthletesStudies 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
- Randomized controlled trail 2 groups treatment - HBOT and IHT
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 66 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Assaf-Harofeh Medical Center
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Shay Efrati, Assaf-Harofeh Medical Center
- Investigators
- Shai a Efrati, MD, Principal investigator, Asaf-Harofhe MC
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05447416
- Sponsor's protocol ID
- 0032-20-ASF
- Status last verified
- Apr 2026
- First submitted
- 3 Jul 2022
- Last updated
- 21 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- 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 21 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Intermittent Hypoxic Training (IHT) Versus Hyperbaric Oxygen Therapy (HBOT) for Aerobic Performance - Prospective Randomized Study
- ClinicalTrials.gov ID
- NCT05447416
- Acronym / sponsor ID
- 0032-20-ASF
- Conditions
- Healthy Active Athletes
- Keywords
- triathletes, cyclists, mitochondria, HBOT, HBO, IHT
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 66 participants (estimated)
- Lead sponsor
- Assaf-Harofeh Medical CenterOther government
- Study start
- 1 Jun 2023 (actual)
- Primary completion
- 31 Aug 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 7 Jul 2022 (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.
Comparing the effect of HBOT and IHT on aerobic performance of athletes.
Detailed description
Enhanced physical performance is the goal of all professional and non-professional athletes. There are many intervention methods aim to enhance physical performance from 2 intervention related to change in the environment partial oxygen pressure have been demonstrated to have beneficial effect: IHT and HBOT.
This study offers one of the two interventions to athletes with a pre and post intervention objective evaluation of the physiological performance - Maximal exercise test for evaluating VO2MAX and ventilatory thresholds, time to exhaustion, 30 seconds Wingate test, agility test, muscle biopsy, blood tests, brain MRI, cognitive tests and exercise cognitive test.
After signing an informed consent form, eligible subjects will be randomized to one of the study groups at a ratio of 1:1. The IHT group will receive three hypoxic guided training sessions per week, according an individualized training protocol, 24 sessions in total.
The HBOT group will receive 40 daily hyperbaric sessions, five days per week. Each session will include 90 minutes exposure to 100% oxygen at 2ATA with a five-minute air break every 20 minutes. Three times per week, as the IHT group, the HBOT group will have a guided training session, according an individualized training protocol.
Both groups, IHT and HBOT, will have the same relative intensity guided training protocols for 8 weeks, to stimulate the same exercise load. The IHT group will train for 60 minutes, 3 times a week in a normobaric hypoxia environment, at O2 concentration of 15.2% that stimulates a 2500-2600m height. The HBOT group will train for 60 minutes after the HBOT sessions, 3 times per week, in a normobaric normoxic environment
Physical performance evaluations will be conducted on 3 different times post interventions - a day last intervention, 3 weeks after and 2 months after - in order to analyze the long term effect of each intervention.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Randomized controlled trail 2 groups treatment - HBOT and IHT
| Arm | Type | Receives |
|---|---|---|
| Hyperbaric Oxygen Therapy - HBOT | Active comparator | Device: Hyperbaric Oxygen Therapy - HBOTThe protocol comprises of 40 consecutive hyperbaric oxygen treatment (HBOT) sessions, 5 sessions per week within a two months' period. The HBOT group will train for 60 minutes after the HBOT sessions, 3 times per week, in a normobaric normoxic environment according to individualized training protocol |
| Intermittent Hypoxic Training - IHT | Active comparator | Device: Intermittent Hypoxic Training - IHTThe protocol comprises of 24 consecutive Intermittent Hypoxic Training (IHT) sessions, 3 sessions per week within a two months' period. Subjects will train according to individualized training protocol. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Vo2max above 3500 ml or Vo2max/kg above 50 ml/kg
- Age 18-45
- Subjects are active aerobic athletes, training regularly more than 4 exercise sessions per week.
- Subject willing and able to read, understand and sign an informed consent
Key exclusion criteria (12 listed)
- Inability to attend scheduled clinic visits and/or comply with the study protocol
- Active malignancy
- Active smokers
- Previous treatment of HBOT for any reason prior to study enrollment.
- Chest pathology incompatible with pressure changes
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 |
|---|---|---|
| Hyperbaric Oxygen Therapy - HBOTEach session will include exposure of 90 minutes to 100% at 2 ATA, with 5 minutes air breaks every 20 minutes | Device | Hyperbaric Oxygen Therapy - HBOT |
| Intermittent Hypoxic Training - IHTEach session lasts 60 minutes of 15.2% oxygen at 1.0 ATA. Subjects will be training according to individualized training protocol. | Device | Intermittent Hypoxic Training - IHT |
Primary outcome
Cardiopulmonary exercise test (CPET)
Time frame: Baseline, 11 weeks
CPET determines the gas exchange dynamics that is expected to change through the intervention
8 secondary outcomes
Cardiopulmonary exercise test (CPET)
Time frame: 8 weeks, 16 weeks
Time To Exhaustion
Time frame: Baseline, 11 weeks, 16 weeks
Wingate 30 seconds anaerobic test
Time frame: Baseline, 11 weeks, 16 weeks
Muscle biopsy for mitochondrial function
Time frame: Baseline, 11 weeks
Blood test for evaluation of CBC
Time frame: Baseline, 11 weeks, 16 weeks
Blood test for evaluation of HIF-1α
Time frame: Baseline, 7 weeks, 8 weeks, 11 weeks, 16 weeks
Blood test for evaluation of Telomeres length
Time frame: Baseline,11 weeks, 16 weeks
Blood test for evaluation of mitochondrial function
Time frame: Baseline,11 weeks
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 21 Apr 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.
Shai a Efrati, MD principal investigator
Asaf-Harofhe MC
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Hyperbaric Oxygen Therapy - HBOT and Intermittent Hypoxic Training - IHT in people with Healthy Active Athletes, run by Assaf-Harofeh Medical Center at 1 site in Israel.
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 12 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 21 Apr 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 Israel. 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 Shai Efrati, Prof (972-8-9779393, efratishai@outlook.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Cardiopulmonary exercise test (CPET) (time frame: Baseline, 11 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 21 Apr 2026.