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Effect of Pre-exercise Inhalation of Molecular Hydrogen on Metabolic Response During Graded Exercise in Healthy Women

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

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07644000
Enrollment
22
Registered
2026-06-12
Start date
2026-06-22
Completion date
2026-12-01
Last updated
2026-06-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy Adult Females

Keywords

molecular hydrogen, metabolic response

Brief 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? 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.

Interventions

Gas mixture containing 3.75% molecular hydrogen and ambient air.

OTHERPlacebo

Ambient air without molecular hydrogen.

Sponsors

Palacky University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 30 Years
Healthy volunteers
Yes

Inclusion criteria

* Healthy female participants. * Regular menstrual cycle with exercise testing scheduled outside the menstrual phase. * Signed informed consent.

Exclusion criteria

* 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.

Design outcomes

Primary

MeasureTime frameDescription
Respiratory exchange ratioChange 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.

Secondary

MeasureTime frameDescription
Oxygen uptakeChange after 2 weeks of crossover.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.
Carbon dioxide productionChange after 2 weeks of crossover.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.
Minute ventilationChange after 2 weeks of crossover.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.
Breathing frequencyChange after 2 weeks of crossover.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.
Heart rateChange after 2 weeks of crossover.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.
Blood lactate concentrationChange after 2 weeks of crossover.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).
Rating of perceived exertionChange after 2 weeks of crossover.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".

Countries

Czechia

Contacts

CONTACTTereza Rysava
tereza.rysava01@upol.cz+420585636154
CONTACTJakub Krejci, PhD
jakub.krejci@upol.cz
PRINCIPAL_INVESTIGATORTereza Rysava

Palacky University

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 26, 2026