NCT07201935

Brief Summary

This pilot study investigates the effects of cold-water immersion, traditional sauna use, and their combination on sleep architecture, glymphatic clearance, and psycho-affective health in military cadets. The study uses wearable technologies including the Oura Ring and the Applied Cognition Glymphatic Monitor to collect objective sleep and physiological data.

Trial Health

63
Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
45

participants targeted

Target at P25-P50 for not_applicable

Timeline
5mo left

Started Apr 2026

Shorter than P25 for not_applicable

Geographic Reach
1 country

1 active site

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress20%
Apr 2026Oct 2026

First Submitted

Initial submission to the registry

September 12, 2025

Completed
19 days until next milestone

First Posted

Study publicly available on registry

October 1, 2025

Completed
6 months until next milestone

Study Start

First participant enrolled

April 1, 2026

Completed
6 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

October 1, 2026

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

October 1, 2026

Last Updated

March 13, 2026

Status Verified

March 1, 2026

Enrollment Period

6 months

First QC Date

September 12, 2025

Last Update Submit

March 12, 2026

Conditions

Cold-water ImmersionHigh Heat SaunaCombination of Cold-water Immersion and High Heat Sauna

Keywords

Glymphatic SystemSleep qualitySleep architectureThermodynamic exposure

Outcome Measures

Primary Outcomes (4)

  • Glymphatic clearance

    Changes in parenchymal resistance during sleep

    End of baseline monitoring phase (Day 7), end of intervention week 1 (Day 14), and end of intervention (Day 28)

  • Sleep Efficiency

    Percentage of sleep period spent asleep measured by the Oura Ring (percentage, %)

    Each night of the baseline monitoring period (7days) and intervention phase (14days)

  • Pittsburgh Sleep Quality Index

    Self-reported sleep quality

    At the end of the baseline monitoring phase (Day 7), end of intervention week 1 (Day 14), and end of intervention phase (Day 28)

  • Profile of Mood States: Total Mood Disturbance

    Self-reported mood disturbance used by summing all negative profiled mood sub-scores (tension, depression, anger/hostility, fatigue, and confusion) and subtracting the positive profiled mood sub-score (vigor). (score -32 - 200, higher equals greater mood disturbance)

    At the end of the baseline monitoring phase (Day 7), end of intervention week 1 (Day 14), and end of intervention phase (Day 28)

Secondary Outcomes (15)

  • Total Sleep Duration

    Each night of the baseline monitoring period (7days) and intervention phase (14days)

  • REM Sleep Duration

    Each night of the baseline monitoring period (7days) and intervention phase (14days)

  • Deep Sleep Duration

    Each night of the baseline monitoring period (7days) and intervention phase (14days)

  • Light Sleep Duration

    Each night of the baseline monitoring period (7days) and intervention phase (14days)

  • Restless Sleep Duration

    Each night of the baseline monitoring period (7days) and intervention phase (14days)

  • +10 more secondary outcomes

Study Arms (3)

Cold-water immersion

EXPERIMENTAL

5 minutes of cold-water immersion (submerged up to chin) at 8 - 10C°(46.4 - 50F°) in the morning between 6:00 - 8:00am.

Behavioral: Cold Water Immersion

High heat sauna

EXPERIMENTAL

20 minutes of high heat sauna at 90 - 94C° (190 - 201.2F°) between 5:00 - 7:00pm

Behavioral: High Heat Sauna

Combination

EXPERIMENTAL

5 minutes of cold-water immersion (submerged up to chin) at 8 - 10C°(46.4 - 50F°) in the morning between 6:00 - 8:00am and 20 minutes of high heat sauna at 90 - 94C° (190 - 201.2F°) between 5:00 - 7:00pm

Behavioral: Cold Water ImmersionBehavioral: High Heat Sauna

Interventions

Cold Water ImmersionBEHAVIORAL

Participants will complete 14 daily sessions of cold-water immersion exposure.

Cold-water immersionCombination
High Heat SaunaBEHAVIORAL

Participants will complete 14 evening sessions in the high heat sauna

CombinationHigh heat sauna

Eligibility Criteria

Age18 Years - 30 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • years of age
  • Member of the Ranger Challenge group at The Citadel.
  • Access to a smartphone with access to appropriate app marketplace (Apple iOS 15, Android 8.0 or newer) and reliable data access.
  • Ability to access and operate Oura Ring application

You may not qualify if:

  • Medical contraindications to continuous wearing of the Oura Ring.
  • Current diagnosis of neurological, cardiovascular, and/or sleep disorder.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

The Citadel Military College

Charleston, South Carolina, 29404, United States

Location

MeSH Terms

Conditions

Sleep Initiation and Maintenance Disorders

Condition Hierarchy (Ancestors)

Sleep Disorders, IntrinsicDyssomniasSleep Wake DisordersNervous System DiseasesMental Disorders

Study Officials

  • Mark Rosenberg, MD

    Medical University of South Carolina

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

September 12, 2025

First Posted

October 1, 2025

Study Start

April 1, 2026

Primary Completion (Estimated)

October 1, 2026

Study Completion (Estimated)

October 1, 2026

Last Updated

March 13, 2026

Record last verified: 2026-03

Locations

US(1)