Cold-water Immersion, High Heat Sauna, Combination of Cold-water Immersion and High Heat Sauna
Conditions
Keywords
Glymphatic System, Sleep quality, Sleep architecture, Thermodynamic exposure
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.
Detailed description
The study will enroll 45 military cadets from The Citadel Military College, randomized into three groups: Cold-Water Immersion (CWI), High Heat Sauna (HHS), and Combined (COM). Participants will undergo a 7-day baseline period followed by a 14-day intervention. Sleep architecture, glymphatic function, and psycho-affective health will be assessed using validated wearable devices and questionnaires. The study aims to identify intervention-specific improvements in sleep and glymphatic clearance.
Interventions
BEHAVIORALCold Water Immersion
Participants will complete 14 daily sessions of cold-water immersion exposure.
BEHAVIORALHigh Heat Sauna
Participants will complete 14 evening sessions in the high heat sauna
Sponsors
Medical University of South Carolina
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* 18 - 30 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
Exclusion criteria
* Medical contraindications to continuous wearing of the Oura Ring. * Current diagnosis of neurological, cardiovascular, and/or sleep disorder.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Pittsburgh Sleep Quality Index | At the end of the baseline monitoring phase (Day 7), end of intervention week 1 (Day 14), and end of intervention phase (Day 28) | Self-reported sleep quality |
| Profile of Mood States: Total 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) | 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) |
| Glymphatic clearance | End of baseline monitoring phase (Day 7), end of intervention week 1 (Day 14), and end of intervention (Day 28) | Changes in parenchymal resistance during sleep |
| Sleep Efficiency | Each night of the baseline monitoring period (7days) and intervention phase (14days) | Percentage of sleep period spent asleep measured by the Oura Ring (percentage, %) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Light Sleep Duration | Each night of the baseline monitoring period (7days) and intervention phase (14days) | Duration of sleep period spent in light (N1 or N2) sleep (seconds, s) |
| Restless Sleep Duration | Each night of the baseline monitoring period (7days) and intervention phase (14days) | Duration of sleep period with increased registered movements as measured by the Oura Ring (seconds, s) |
| Wake After Sleep Onset (WASO) Duration | Each night of the baseline monitoring period (7days) and intervention phase (14days) | Total time spent awake after falling asleep (seconds, s) |
| RMSSD | Each night of the baseline monitoring period (7days) and intervention phase (14days) | Root mean squared of temporal latency between successive heart beats throughout sleep period measured by the Oura Ring (milliseconds, ms) |
| Nighttime Skin Temperature | Each night of the baseline monitoring period (7days) and intervention phase (14days) | Skin temperature (degrees Celsius, C°) throughout sleep period measured by the Oura Ring. |
| Profile of Mood States: Tension/Anxiety | End of baseline monitoring period (Day 7), end of intervention week 1 (Day 14), and end of intervention (Day 28). | Tension/Anxiety sub-score computed from the POMS (score 0 - 36, higher equals more tension/anxiety) |
| Profile of Mood States: Depression | End of baseline monitoring period (Day 7), end of intervention week 1 (Day 14), and end of intervention (Day 28) | Depression sub-score from the POMS (score 0 - 60, higher equals greater depression) |
| Profile of Mood States: Anger/Hostility | End of baseline monitoring period (Day 7), end of intervention week 1 (Day 14), and end of intervention (Day 28) | Anger/Hostility sub-score from the POMS (score 0 - 48, higher equals greater anger/hostility) |
| Profile of Mood States: Vigor | End of baseline monitoring period (Day 7), end of intervention week 1 (Day 14), and end of intervention (Day 28) | Vigor sub-score from the POMS (score 0 - 32, higher equals more vigor) |
| Profile of Mood States: Fatigue | End of baseline monitoring period (Day 7), end of intervention week 1 (Day 14), and end of intervention (Day 28) | Fatigue sub-score from the POMS (score 0 - 28, higher equals more fatigue) |
| Sleep Time Heart Rate | Each night of the baseline monitoring period (7days) and intervention phase (14days) | Average heart rate during sleep (beats per minute, bpm) |
| Profile of Mood States: Confusion | End of baseline monitoring period (Day 7), end of intervention week 1 (Day 14), and end of intervention (Day 28) | Confusion sub-score from the POMS (score 0 - 28, higher equals more confusion) |
| Total Sleep Duration | Each night of the baseline monitoring period (7days) and intervention phase (14days) | Total duration of sleep period measured by the Oura Ring (seconds, s) |
| REM Sleep Duration | Each night of the baseline monitoring period (7days) and intervention phase (14days) | Duration of sleep period spent in REM sleep measured by the Oura Ring (seconds, s) |
| Deep Sleep Duration | Each night of the baseline monitoring period (7days) and intervention phase (14days) | Duration of sleep periods spent in deep (N3) sleep (seconds, s) |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORMark Rosenberg, MD
Medical University of South Carolina
Outcome results
None listed