UMIN-CTR Clinical Trial
| Unique ID issued by UMIN | UMIN000062950 |
|---|---|
| Receipt number | R000072043 |
| Scientific Title | Effects of Underwater Walking in a Hydrogen-Enriched Water Pool on Peripheral Circulation: A Non-Randomized Cross-Over Interventional Study |
| Date of disclosure of the study information | 2026/09/18 |
| Last modified on | 2026/09/16 12:55:55 |
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Basic information
Public title
Effects of 15-minute water walking in a hydrogen pool on blood flow
Acronym
Hydrogen pool study 2026
Scientific Title
Effects of Underwater Walking in a Hydrogen-Enriched Water Pool on Peripheral Circulation: A Non-Randomized Cross-Over Interventional Study
Scientific Title:Acronym
Hydrogen-Enriched Water Pool: Interventional study 2026
Region
| Japan |
Condition
Condition
Healthy
Classification by specialty
| Adult |
Classification by malignancy
Others
Genomic information
NO
Objectives
Narrative objectives1
To investigate the acute effect of 15-minute water walking in a hydrogen-enriched water pool on peripheral blood flow by comparing it with water walking in a pool without hydrogen bubbling in the same participants. The study also exploratively evaluates the effects on physiological outcomes, including blood lactate concentration, urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), peripheral oxygen saturation (SpO2), heart rate, perfusion index (PI), Subjective Well Being Inventory (SUBI) questionnaire.
Basic objectives2
Efficacy
Basic objectives -Others
Trial characteristics_1
Trial characteristics_2
Developmental phase
Assessment
Primary outcomes
Peripheral capillary blood flow: difference in blood flow between the hydrogen and control conditions. Measurements were taken before walking and at 5, 10, and 15 minutes after walking.
Key secondary outcomes
Blood lactate concentration, urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), peripheral oxygen saturation (SpO2), heart rate, perfusion index (PI), and Subjective Well-Being Inventory (SUBI) are measured and assessed under each water-walking condition at baseline (before water walking) and 5 minutes after completion of water walking.
Base
Study type
Interventional
Study design
Basic design
Cross-over
Randomization
Non-randomized
Randomization unit
Blinding
Open -no one is blinded
Control
No treatment
Stratification
Dynamic allocation
Institution consideration
Blocking
Concealment
Intervention
No. of arms
2
Purpose of intervention
Treatment
Type of intervention
| Other |
Interventions/Control_1
Hydrogen condition: Participants performed 15 minutes of water walking in a 32 degrees C experimental pool. Molecular hydrogen gas generated by the HX1600 inhalation system (Helix Japan Co., Ltd.) was continuously bubbled into the pool water during the intervention. Before the start of walking, the dissolved hydrogen concentration was measured near the water surface at the center of the pool using a hydrogen concentration meter (Field New Co., Ltd.) and confirmed to be approximately 1.0 ppm. Hydrogen bubbling was continued throughout the 15-minute walking intervention. Subjects walked back and forth in a 1.5 m x 3.0 m pool at a constant pace of 5 cycles per minute (approximately 25 m/min).
Interventions/Control_2
Control condition: Participants performed 15 minutes of water walking in a 32 degrees C experimental pool without bubbling molecular hydrogen gas. The dissolved hydrogen concentration of the pool water was measured using the same hydrogen concentration meter and confirmed to be 0 ppm. Subjects walked back and forth in a 1.5 m x 3.0 m pool at a constant pace of 5 cycles per minute (approximately 25 m/min).
Interventions/Control_3
Interventions/Control_4
Interventions/Control_5
Interventions/Control_6
Interventions/Control_7
Interventions/Control_8
Interventions/Control_9
Interventions/Control_10
Eligibility
Age-lower limit
| 35 | years-old | <= |
Age-upper limit
| 80 | years-old | >= |
Gender
Male and Female
Key inclusion criteria
Inclusion criteria were: (1) age between 55 and 80 years; (2) ability to perform light aquatic exercise safely; (3) absence of chronic medication use affecting circulation or metabolism; and (4) provision of written informed consent.
Key exclusion criteria
Exclusion criteria included: (1) history of cardiovascular, pulmonary, or metabolic disease; (2) active dermatologic conditions that could interfere with water immersion; (3) psychiatric disorders or cognitive impairment; and (4) inability to complete both experimental sessions.
Target sample size
11
Research contact person
Name of lead principal investigator
| 1st name | NAOKO |
| Middle name | |
| Last name | HITOSUGI |
Organization
Jin-Ai-Kai Medical Corporation
Division name
Muse Dermatology and Pain Clinic
Zip code
3360021
Address
7-2-1-102, Bessho, Minami-ku, Saitama, Japan
TEL
0488664112
naoko1121daiya@gmail.com
Public contact
Name of contact person
| 1st name | DAIYA |
| Middle name | |
| Last name | OZAKI |
Organization
Daiya-Kai Medical Corporation
Division name
Musashiurawa Orthopaedic and Internal Medicine Clinic
Zip code
336-0021
Address
7-2-1-101A, Bessho, Minami-ku, Saitama, Japan
TEL
0488444115
Homepage URL
daiya@nms.ac.jp
Sponsor or person
Institute
Muse Dermatology and Pain Clinic
Institute
Department
Personal name
Funding Source
Organization
Muse Dermatology and Pain Clinic
Organization
Division
Category of Funding Organization
Other
Nationality of Funding Organization
Other related organizations
Co-sponsor
Name of secondary funder(s)
IRB Contact (For public release)
Organization
Muse Dermatology and Pain Clinic
Address
7-2-1-102, Bessho, Minami-ku, Saitama, Japan
Tel
0488664112
634muse@gmail.com
Secondary IDs
Secondary IDs
NO
Study ID_1
Org. issuing International ID_1
Study ID_2
Org. issuing International ID_2
IND to MHLW
Institutions
Institutions
Other administrative information
Date of disclosure of the study information
| 2026 | Year | 09 | Month | 18 | Day |
Related information
URL releasing protocol
Publication of results
Unpublished
Result
URL related to results and publications
Number of participants that the trial has enrolled
11
Results
Results date posted
Results Delayed
Results Delay Reason
Date of the first journal publication of results
Baseline Characteristics
Participant flow
Adverse events
Outcome measures
Plan to share IPD
IPD sharing Plan description
Progress
Recruitment status
Completed
Date of protocol fixation
| 2026 | Year | 04 | Month | 01 | Day |
Date of IRB
| 2026 | Year | 03 | Month | 01 | Day |
Anticipated trial start date
| 2026 | Year | 04 | Month | 01 | Day |
Last follow-up date
| 2026 | Year | 07 | Month | 31 | Day |
Date of closure to data entry
Date trial data considered complete
Date analysis concluded
Other
Other related information
Management information
Registered date
| 2026 | Year | 09 | Month | 16 | Day |
Last modified on
| 2026 | Year | 09 | Month | 16 | Day |
Link to view the page
Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000072043
