Healthy Adult FemalesNCT07644000
Effect of Pre-exercise Inhalation of Molecular Hydrogen on Metabolic Response During Graded Exercise in Healthy Women
A study testing Molecular hydrogen in people with Healthy Adult Females, run by Palacky University at 1 site in Czechia.
Trial summary
The goal of this clinical trial is to evaluate if molecular hydrogen can reduce the metabolic response during graded exercise in healthy women aged 18-30 years. The main questions it aims to answer are: Does molecular hydrogen reduce the respiratory exchange ratio? Does molecular hydrogen reduce oxygen uptake?… Read more about this study
- Who is it for?
- Ages 18 to 30 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Healthy Adult Females
- What is being tested?
- Molecular hydrogen
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 22 participants
- Where
- 1 siteCzechia
- Study dates
- 22 Jun 2026to Dec 2026
- 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 30 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy female participants.
- Regular menstrual cycle with exercise testing scheduled outside the menstrual phase.
- Signed informed consent.
Who cannot join
- Pregnancy or breastfeeding.
- History or presence of cardiovascular disease.
- History or presence of respiratory disease.
- Regular use of medications affecting metabolism.
- Use of dietary supplements affecting metabolism within 14 days prior to intervention.
- Strenuous physical activity within 24 hours prior to exercise testing.
- Any contraindication to exercise testing or study participation determined by a physician.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Jakub Krejci, PhD contact
Czechia1 site, 1 recruiting
- Recruiting
Palacky University, Faculty of Physical Culture
Olomouc, 77111
Tereza Rysava, +420585636154, tereza.rysava01@upol.cz
About this study
Official title: Effect of Repeated Pre-exercise Inhalation of Molecular Hydrogen on Metabolic Response During Graded Exercise in Healthy Women: A Randomized, Double-blind, Placebo-controlled Crossover Trial
The goal of this clinical trial is to evaluate if molecular hydrogen can reduce the metabolic response during graded exercise in healthy women aged 18-30 years. The main questions it aims to answer are:
- Does molecular hydrogen reduce the respiratory exchange ratio?
- Does molecular hydrogen reduce oxygen uptake?
Researchers will compare molecular hydrogen to a placebo (ambient air containing no molecular hydrogen) to see if molecular hydrogen reduces the metabolic response.
Participants will:
- Inhale molecular hydrogen for 60 minutes each day for 7 days.
- Undergo an exercise testing twice after a two-week washout period.
Read the detailed description
This crossover trial examines the effect of repeated inhalation of molecular hydrogen on the metabolic response during graded exercise in healthy female participants. Each participant undergoes two experimental interventions (molecular hydrogen and placebo) in random order, separated by a two-week washout period. The order of the interventions is randomized using a computer random number generator. Each intervention consists of 7 days, during which participants inhale either molecular hydrogen or placebo gas for 60 minutes daily under resting conditions. Molecular hydrogen is produced by electrolysis of water and mixed with ambient air in the chamber to achieve a hydrogen concentration of 3.75 % which is below the lower explosive limit. This gas is administered via a face mask connected to an Ambu bag system with a one-way valve to ensure standardized delivery. Placebo is produced by pumping ambient air without molecular hydrogen. Molecular hydrogen is colorless, odorless, and tasteless, making it indistinguishable from placebo by human senses. On the 7th day of each intervention, participants undergo a graded exercise test on an bicycle ergometer immediately following the final inhalation session. The protocol consists of 8 incremental steps with the workload increasing from 0.5 to 2.25 W/kg. Outcome measures collected at rest before exercise and during exercise include cardiorespiratory variables, capillary blood biomarkers, and perceived exertion. Statistical analysis is based on a two-way analysis of variance for repeated measures, and p < 0.05 is considered statistically significant.
- Conditions
- Healthy Adult Females
- Being tested
- Molecular hydrogen, Placebo
- Keywords
- molecular hydrogen, metabolic response
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Molecular hydrogenOther
Also called H2 Air-Blend Generator (H2 Medical Technologies, Ostrava, Czech Republic)
Gas mixture containing 3.75% molecular hydrogen and ambient air.
PlaceboOther
Ambient air without molecular hydrogen.
| Study group | Role | What they receive |
|---|---|---|
| Molecular hydrogen | Experimental | Molecular hydrogen inhalation for 60 minutes daily for 7 days. Receives: Other: Molecular hydrogen |
| Placebo | Placebo comparator | Ambient air inhalation for 60 minutes daily for 7 days. Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Respiratory exchange ratio
Respiratory exchange ratio is measured using an Ergostik analyser (Geratherm Respiratory, Bad Kissinger, Germany) breath by breath during the exercise, and the average is calculated for 6-minute segments for subsequent analysis.
Measured: Change after 2 weeks of crossover.
Secondary outcomes (7)
Oxygen uptake
Oxygen uptake is measured using an Ergostik analyser (Geratherm Respiratory, Bad Kissinger, Germany) breath by breath during the exercise, and the average is calculated for 6-minute segments for subsequent analysis.
Measured: Change after 2 weeks of crossover.
Carbon dioxide production
Carbon dioxide production is measured using an Ergostik analyser (Geratherm Respiratory, Bad Kissinger, Germany) breath by breath during the exercise, and the average is calculated for 6-minute segments for subsequent analysis.
Measured: Change after 2 weeks of crossover.
Minute ventilation
Minute ventilation is measured using an Ergostik analyser (Geratherm Respiratory, Bad Kissinger, Germany) breath by breath during the exercise, and the average is calculated for 6-minute segments for subsequent analysis.
Measured: Change after 2 weeks of crossover.
Breathing frequency
Breathing frequency is measured using an Ergostik analyser (Geratherm Respiratory, Bad Kissinger, Germany) breath by breath during the exercise, and the average is calculated for 6-minute segments for subsequent analysis.
Measured: Change after 2 weeks of crossover.
Heart rate
Heart rate is continuously recorded during the exercise using a Polar H10 chest strap (Polar, Kempele, Finland), and the average is calculated for 6-minute segments for subsequent analysis.
Measured: Change after 2 weeks of crossover.
Blood lactate concentration
Capillary blood lactate concentration is assessed at baseline (resting condition) and during the final minute of each exercise step using a Lactate Scout device (EKF Diagnostics, Barleben, Germany).
Measured: Change after 2 weeks of crossover.
Rating of perceived exertion
Participants are asked to subjectively rate their perceived exertion at specified time points - at rest and subsequently in the last minute of each exercise step. The Borg's scale 6-20 is used, where 6 means "no exertion" and 20 means "maximal exertion".
Measured: Change after 2 weeks of crossover.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Jun 2026
- Study start22 Jun 2026
- Primary completionDec 2026 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy Adult FemalesStudies 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 22 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Palacky University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jakub Krejci, Palacky University
- Investigators
- Tereza Rysava, Principal investigator, Palacky University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07644000
- Sponsor's protocol ID
- FTK_2026_14
- Status last verified
- Jun 2026
- First submitted
- 8 Jun 2026
- Last updated
- 25 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: All IPD that underlie results in a publication.
Study at a glance
From the registry record, last updated by the sponsor on 25 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Repeated Pre-exercise Inhalation of Molecular Hydrogen on Metabolic Response During Graded Exercise in Healthy Women: A Randomized, Double-blind, Placebo-controlled Crossover Trial
- ClinicalTrials.gov ID
- NCT07644000
- Acronym / sponsor ID
- FTK_2026_14
- Conditions
- Healthy Adult Females
- Keywords
- molecular hydrogen, metabolic response
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 22 participants (estimated)
- Lead sponsor
- Palacky UniversityUniversity, hospital or other
- Study start
- 22 Jun 2026 (actual)
- Primary completion
- Dec 2026 (estimated)
- Study completion
- Dec 2026 (estimated)
- First posted
- 12 Jun 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.
The goal of this clinical trial is to evaluate if molecular hydrogen can reduce the metabolic response during graded exercise in healthy women aged 18-30 years. The main questions it aims to answer are:
- Does molecular hydrogen reduce the respiratory exchange ratio?
- Does molecular hydrogen reduce oxygen uptake?
Researchers will compare molecular hydrogen to a placebo (ambient air containing no molecular hydrogen) to see if molecular hydrogen reduces the metabolic response.
Participants will:
- Inhale molecular hydrogen for 60 minutes each day for 7 days.
- Undergo an exercise testing twice after a two-week washout period.
Detailed description
This crossover trial examines the effect of repeated inhalation of molecular hydrogen on the metabolic response during graded exercise in healthy female participants. Each participant undergoes two experimental interventions (molecular hydrogen and placebo) in random order, separated by a two-week washout period. The order of the interventions is randomized using a computer random number generator. Each intervention consists of 7 days, during which participants inhale either molecular hydrogen or placebo gas for 60 minutes daily under resting conditions. Molecular hydrogen is produced by electrolysis of water and mixed with ambient air in the chamber to achieve a hydrogen concentration of 3.75 % which is below the lower explosive limit. This gas is administered via a face mask connected to an Ambu bag system with a one-way valve to ensure standardized delivery. Placebo is produced by pumping ambient air without molecular hydrogen. Molecular hydrogen is colorless, odorless, and tasteless, making it indistinguishable from placebo by human senses. On the 7th day of each intervention, participants undergo a graded exercise test on an bicycle ergometer immediately following the final inhalation session. The protocol consists of 8 incremental steps with the workload increasing from 0.5 to 2.25 W/kg. Outcome measures collected at rest before exercise and during exercise include cardiorespiratory variables, capillary blood biomarkers, and perceived exertion. Statistical analysis is based on a two-way analysis of variance for repeated measures, and p < 0.05 is considered statistically significant.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Molecular hydrogen | Experimental | Other: Molecular hydrogenMolecular hydrogen inhalation for 60 minutes daily for 7 days. |
| Placebo | Placebo comparator | Other: PlaceboAmbient air inhalation for 60 minutes daily for 7 days. |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Healthy female participants.
- Regular menstrual cycle with exercise testing scheduled outside the menstrual phase.
- Signed informed consent.
Key exclusion criteria (7 listed)
- Pregnancy or breastfeeding.
- History or presence of cardiovascular disease.
- History or presence of respiratory disease.
- Regular use of medications affecting metabolism.
- Use of dietary supplements affecting metabolism within 14 days prior to intervention.
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 |
|---|---|---|
| Molecular hydrogenAlso: H2 Air-Blend Generator (H2 Medical Technologies, Ostrava, Czech Republic)Gas mixture containing 3.75% molecular hydrogen and ambient air. | Other | Molecular hydrogen |
| PlaceboAmbient air without molecular hydrogen. | Other | Placebo |
Primary outcome
Respiratory exchange ratio
Time frame: Change after 2 weeks of crossover.
Respiratory exchange ratio is measured using an Ergostik analyser (Geratherm Respiratory, Bad Kissinger, Germany) breath by breath during the exercise, and the average is calculated for 6-minute segments for subsequent analysis.
7 secondary outcomes
Oxygen uptake
Time frame: Change after 2 weeks of crossover.
Carbon dioxide production
Time frame: Change after 2 weeks of crossover.
Minute ventilation
Time frame: Change after 2 weeks of crossover.
Breathing frequency
Time frame: Change after 2 weeks of crossover.
Heart rate
Time frame: Change after 2 weeks of crossover.
Blood lactate concentration
Time frame: Change after 2 weeks of crossover.
Rating of perceived exertion
Time frame: Change after 2 weeks of crossover.
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 25 Jun 2026.
- Individual participant dataSharing planned: Yes. All IPD that underlie results in a publication.
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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.
Jakub Krejci, PhD contact
Tereza Rysava principal investigator
Palacky University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Molecular hydrogen in people with Healthy Adult Females, run by Palacky University at 1 site in Czechia.
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 3 inclusion and 7 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 25 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 Czechia. 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. 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?
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 Tereza Rysava (+420585636154, tereza.rysava01@upol.cz), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Respiratory exchange ratio (time frame: Change after 2 weeks of crossover.). 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 25 Jun 2026.