UMIN-ICDS Clinical Trial
| Unique ID issued by UMIN | UMIN000063006 |
|---|---|
| Receipt number | R000072129 |
| Scientific Title | Immediate Effects of Hot Spring Bathing on Well-Being-Related Outcomes and Cognitive Alertness: A Pilot Randomized Crossover Trial |
| Date of disclosure of the study information | 2026/09/24 |
| Last modified on | 2026/09/21 08:24:48 |
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Basic information
Public title
Immediate Effects of Hot Spring Bathing on Well-Being-Related Outcomes and Cognitive Alertness: A Pilot Randomized Crossover Trial
Acronym
Immediate Effects of Hot Spring Bathing on Well-Being-Related Outcomes and Cognitive Alertness
Scientific Title
Immediate Effects of Hot Spring Bathing on Well-Being-Related Outcomes and Cognitive Alertness: A Pilot Randomized Crossover Trial
Scientific Title:Acronym
Immediate Effects of Hot Spring Bathing on Well-Being-Related Outcomes and Cognitive Alertness
Region
| Japan |
Condition
Condition
Healthy adult men
Classification by specialty
| Adult |
Classification by malignancy
Others
Genomic information
NO
Objectives
Narrative objectives1
To investigate the immediate effects of Zao hot spring bathing on well-being-related outcomes and cognitive alertness in a pilot randomized crossover trial.
Basic objectives2
Efficacy
Basic objectives -Others
Trial characteristics_1
Confirmatory
Trial characteristics_2
Developmental phase
Assessment
Primary outcomes
Japanese version of the Restorative Outcome Scale
Key secondary outcomes
Physiological tension, psychological calmness, and cognitive tension assessed using the Short-form self-report measure to assess relaxation effects (S-MARE)
Positive and negative affect assessed using the Japanese version of the Positive and Negative Affect Schedule (PANAS)
Electroencephalogram-derived emotional indices assessed using the KANSEI Analyzer
Voice-derived autonomic nervous system indices assessed using MindScale
Mean reciprocal reaction time, fastest 10% reaction time, slowest 10% reaction time, lapses, and number of false starts assessed using the Psychomotor Vigilance Task-Brief (PVT-B)
Heart rate and heart rate variability
Skin temperature
Subjective well-being
Base
Study type
Interventional
Study design
Basic design
Cross-over
Randomization
Randomized
Randomization unit
Individual
Blinding
Open -no one is blinded
Control
Active
Stratification
NO
Dynamic allocation
Institution consideration
Blocking
Concealment
Intervention
No. of arms
6
Purpose of intervention
Treatment
Type of intervention
| Other |
Interventions/Control_1
A: Indoor plain hot-water bathing
B: Indoor Zao hot spring bathing
C: Outdoor Zao hot spring bathing
Participants undergo conditions A, B, and C in this order. In each condition, participants bathe for up to 10 minutes, with an interval of at least 7 days between conditions.
Interventions/Control_2
A: Indoor plain hot-water bathing
B: Indoor Zao hot spring bathing
C: Outdoor Zao hot spring bathing
Participants undergo conditions A, C, and B in this order. In each condition, participants bathe for up to 10 minutes, with an interval of at least 7 days between conditions.
Interventions/Control_3
A: Indoor plain hot-water bathing
B: Indoor Zao hot spring bathing
C: Outdoor Zao hot spring bathing
Participants undergo conditions B, A, and C in this order. In each condition, participants bathe for up to 10 minutes, with an interval of at least 7 days between conditions.
Interventions/Control_4
A: Indoor plain hot-water bathing
B: Indoor Zao hot spring bathing
C: Outdoor Zao hot spring bathing
Participants undergo conditions B, C, and A in this order. In each condition, participants bathe for up to 10 minutes, with an interval of at least 7 days between conditions.
Interventions/Control_5
A: Indoor plain hot-water bathing
B: Indoor Zao hot spring bathing
C: Outdoor Zao hot spring bathing
Participants undergo conditions C, A, and B in this order. In each condition, participants bathe for up to 10 minutes, with an interval of at least 7 days between conditions.
Interventions/Control_6
A: Indoor plain hot-water bathing
B: Indoor Zao hot spring bathing
C: Outdoor Zao hot spring bathing
Participants undergo conditions C, B, and A in this order. In each condition, participants bathe for up to 10 minutes, with an interval of at least 7 days between conditions.
Interventions/Control_7
Interventions/Control_8
Interventions/Control_9
Interventions/Control_10
Eligibility
Age-lower limit
| 20 | years-old | <= |
Age-upper limit
| 64 | years-old | >= |
Gender
Male
Key inclusion criteria
1. Men aged 20-64 years.
2. Individuals who are able to participate in all three bathing conditions during the study period: an indoor plain hot-water bath (control), an indoor Zao hot 3. spring bath (spring water), and an outdoor Zao hot spring bath (spring water and landscape).
4. Individuals who are able to safely undergo whole-body bathing for 5-10 minutes under each condition.
5. Individuals who are able to understand questions and instructions provided in Japanese and complete psychological questionnaires, simplified electroencephalogram measurements, a reading-aloud task, and a cognitive task.
6. Individuals who are considered eligible for participation in the study by the principal investigator.
Key exclusion criteria
1. Individuals who have been advised by a physician to restrict bathing or who are considered by the principal investigator to be unable to safely undergo hot spring bathing.
2. Individuals with serious underlying medical conditions, including severe cardiovascular, cerebrovascular, respiratory, or renal disease.
3. Individuals with uncontrolled hypertension (systolic blood pressure >=180 mmHg or diastolic blood pressure >=110 mmHg) or other medical conditions that may be aggravated by hot spring bathing.
4. Individuals with epilepsy or other neurological disorders that may interfere with electroencephalogram measurements or cognitive testing.
5. Individuals currently receiving treatment for psychiatric disorders or regularly taking psychotropic medications, hypnotics, anxiolytics, or similar medications.
6. Individuals who are unable to bathe in Zao hot spring because of hypersensitivity to strongly acidic sulfur spring water, skin disorders, or other conditions.
7. Individuals who are considered ineligible for participation in the study by the principal investigator.
Target sample size
12
Research contact person
Name of lead principal investigator
| 1st name | Satoshi |
| Middle name | |
| Last name | Seino |
Organization
Yamagata University
Division name
Institute of Well-Being
Zip code
990-9585
Address
Iida-nishi 2-2-2, Yamagata city, Yamagata prefecture
TEL
0236285166
seino.s@med.id.yamagata-u.ac.jp
Public contact
Name of contact person
| 1st name | Satoshi |
| Middle name | |
| Last name | Seino |
Organization
Yamagata University
Division name
Institute of Well-Being
Zip code
990-9585
Address
Iida-nishi 2-2-2, Yamagata city, Yamagata prefecture
TEL
0236285166
Homepage URL
seino.s@med.id.yamagata-u.ac.jp
Sponsor or person
Institute
Yamagata University
Institute
Department
Personal name
Funding Source
Organization
Yamagata University
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
Ethics Committee of Yamagata University School of Medicine
Address
Iida-nishi 2-2-2, Yamagata city, Yamagata prefecture
Tel
023-628-5047
yu-ikekenkyu@jm.kj.yamagata-u.ac.jp
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 | 24 | 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
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
Open public recruiting
Date of protocol fixation
| 2026 | Year | 09 | Month | 17 | Day |
Date of IRB
| 2026 | Year | 09 | Month | 17 | Day |
Anticipated trial start date
| 2026 | Year | 09 | Month | 18 | Day |
Last follow-up date
| 2026 | Year | 10 | 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 | 21 | Day |
Last modified on
| 2026 | Year | 09 | Month | 21 | Day |
Link to view the page
Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000072129
