This pilot study investigates the effects of cold-water immersion, traditional sauna use, and their combination on sleep architecture and psychological health in military cadets. The study uses wearable technologies including the Oura Ring to collect objective sleep and physiological data.
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 and psychological-affective health will be assessed using validated wearable devices and questionnaires. The study aims to identify intervention-specific improvements in sleep and psychological health.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
45
Participants will complete 14 daily sessions of cold-water immersion exposure.
Participants will complete 14 evening sessions in the high heat sauna
The Citadel Military College
Charleston, South Carolina, United States
Sleep Efficiency
Percentage of sleep period spent asleep measured by the Oura Ring (percentage, %)
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Pittsburgh Sleep Quality Index
Self-reported sleep quality
Time frame: At the end of the baseline monitoring phase (Day 7), end of intervention week 1 (Day 14), and end of intervention phase (Day 28)
Brief Mood Introspection Scale
Self-reported assessment of mood consisting of 16 mood adjectives. Participants rate each adjective on a 4-point likert scale (0 = definitely don't feel, 3 = definitely feel). The assessment captures 2 core dimensions of mood valence (pleasant v. unpleasant) and arousal (active v. calm).
Time frame: At the end of the baseline monitoring phase (Day 7), end of intervention week 1 (Day 14), and end of intervention phase (Day 28)
Total Sleep Duration
Total duration of sleep period measured by the Oura Ring (seconds, s)
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
REM Sleep Duration
Duration of sleep period spent in REM sleep measured by the Oura Ring (seconds, s)
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Deep Sleep Duration
Duration of sleep periods spent in deep (N3) sleep (seconds, s)
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Light Sleep Duration
Duration of sleep period spent in light (N1 or N2) sleep (seconds, s)
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Restless Sleep Duration
Duration of sleep period with increased registered movements as measured by the Oura Ring (seconds, s)
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Wake After Sleep Onset (WASO) Duration
Total time spent awake after falling asleep (seconds, s)
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
RMSSD
Root mean squared of temporal latency between successive heart beats throughout sleep period measured by the Oura Ring (milliseconds, ms)
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Nighttime Skin Temperature
Skin temperature (degrees Celsius, C°) throughout sleep period measured by the Oura Ring.
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Sleep Time Heart Rate
Average heart rate during sleep (beats per minute, bpm)
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)