Effect of Molecular Hydrogen Inhalation on Metabolic Response During Low-intensity Exercise on a Bicycle Ergometer

June 22, 2026 updated by: Jakub Krejci, Palacky University

Effect of Molecular Hydrogen Inhalation on Metabolic Response in Healthy Females During Low-intensity Exercise on a Bicycle Ergometer: A Randomized, Double-blind, Placebo-controlled Crossover Trial

This trial evaluates the effect of molecular hydrogen inhalation on metabolic response, heart rate, and rating of perceived exertion in healthy females during 30 minutes of exercise on a bicycle ergometer.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The objective of this randomized, double-blind, placebo-controlled crossover trial is to assess the effect of molecular hydrogen inhalation on metabolic response during 20 min of rest and during exercise on a bicycle ergometer with a workload of 0.5 W/kg for 10 min, 0.75 W/kg for 10 min, and 1 W/kg for 10 min. The trial recruits healthy females aged 20-35 years and the planned sample size is 20. The trial consists of two experimental sessions, one using molecular hydrogen inhalation and the other using placebo inhalation. The washout period between sessions is one week. Randomization of the order of the sessions is performed using a computer random generator. Molecular hydrogen is produced using a hydrogen generator via electrolysis of water and administered through a mouthpiece. Ambient air is used for placebo inhalation. Molecular hydrogen is colorless, odorless, and tasteless, making it indistinguishable from placebo by the human senses. During the session, the following variables are measured: ventilation, oxygen uptake, respiratory exchange ratio, heart rate, rating of perceived exertion, and oxygen saturation. Energy expenditure, fat oxidation rate and carbohydrates oxidation rate are calculated from oxygen uptake and respiratory exchange ratio. Statistical analysis is performed at the 0.05 significance level and data are evaluated using analysis of variance for repeated measures with Fisher's post hoc tests.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

  • Name: Jakub Krejci, PhD
  • Phone Number: +420585636404

Study Locations

  • Czechia
    • Czech Republic
      • Olomouc, Czech Republic, Czechia, 77111
        • Palacky University, Faculty of Physical Culture

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Free of major diseases.
  • Signed informed consent.

Exclusion Criteria:

  • Acute conditions contraindicating laboratory testing of exercise.
  • Cardiorespiratory disease.
  • Pharmacotherapy affecting metabolism.
  • Musculoskeletal problems.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Molecular hydrogen
Molecular hydrogen inhalation for 20 min at rest and 30 min during exercise.
Other: Molecular hydrogen
Hydrogen gas, purity >99.9%, flow rate 600 ml/min (two generators 300 ml/min each).
Other Names:
  • i300 Hydrogen Generator, H2 World Health & Beauty Company, Ostrava, Czech Republic
Placebo Comparator: Placebo
Placebo inhalation for 20 min at rest and 30 min during exercise.
Other: Placebo
Ambient air, flow rate 600 ml/min (two pumps 300 ml/min each).
Other Names:
  • i300 Hydrogen Generator (placebo), H2 World Health & Beauty Company, Ostrava, Czech Republic

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Respiratory exchange ratio
Time Frame: Change after 1 week of crossover.
Respiratory exchange ratio is measured with Ergostik analyser (Geratherm Respiratory, Bad Kissinger, Germany) breath by breath during the session and averaged over 5 min windows for subsequent analysis.
Change after 1 week of crossover.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Ventilation
Time Frame: Change after 1 week of crossover.
Ventilation is measured with Ergostik analyser (Geratherm Respiratory, Bad Kissinger, Germany) breath by breath during the session and averaged over 5 min windows for subsequent analysis.
Change after 1 week of crossover.
Oxygen uptake
Time Frame: Change after 1 week of crossover.
Oxygen uptake is measured with Ergostik analyser (Geratherm Respiratory, Bad Kissinger, Germany) breath by breath during the session and averaged over 5 min windows for subsequent analysis.
Change after 1 week of crossover.
Heart rate
Time Frame: Change after 1 week of crossover.
Heart rate is recorded by Polar H10 chest strap (Polar, Kempele, Finland) during the session and averaged over 5 min windows for subsequent analysis.
Change after 1 week of crossover.
Rating of perceived exertion
Time Frame: Change after 1 week of crossover.
Participants are asked to subjectively rate their perceived exertion at specified time points (at the end of rest, after 10, 20, and 30 min of exercise). The Borg's scale 6 (no exertion) and 20 (maximal exertion) is used.
Change after 1 week of crossover.

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Oxygen saturation
Time Frame: Change after 1 week of crossover.
Oxygen saturation is measured with pulse oximeter (Onyx Vantage 9590, Nonin Medical, Plymouth, MN) at specified time points (every 5 min at rest and every 2,5 min during exercise).
Change after 1 week of crossover.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Palacky University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 5, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 19, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 19, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 23, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 23, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 30, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 25, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 22, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • FTK_2024_101

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

All IPD that underlie results in a publication.

IPD Sharing Time Frame

Beginning 1 month after the publication of results with no end date.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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