Cold ExposureNCT06667193
Cold Water Exposure's Effects on Physical and Mental Health
A study testing Cold Water Immersion (CWI) - Cold Tub Immersion (CI) and Cold Water Immersion (CWI) - Cold Shower (CS) in people with Cold Exposure, run by University of Northern Colorado at 1 site in United States.
Trial summary
An interest in cold-water immersion (CWI) to elicit diverse physiological effects has been prevalent for centuries. CWI typically consists of bodily exposure to water at temperatures ranging from 5-10º C for various durations. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Cold Exposure
- What is being tested?
- Cold Water Immersion (CWI) - Cold Tub Immersion (CI) and Cold Water Immersion (CWI) - Cold Shower (CS)
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 36 participants
- Where
- 1 siteUnited States
- Study dates
- 10 Oct 2024to 1 Dec 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy volunteers
- Aged 18-45
Who cannot join
- Current holds a cold water exposure routine (≥3 sessions in the last month, consisting of ≥4 minutes per immersion)
- Currently pregnant of planning to become pregnant
- Chronic use of anti-inflammatory medication
- Prior history of chronic disease conditions: Cardiovascular Disease, Diabetes, Cancer, Raynaud's Disease, or severe/untreated anxiety or depression
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Northern Colorado
Greeley, Colorado, 80639
About this study
Official title: Cold-Water Immersion's Effects on Physical and Mental Health: A 4-Week Randomized Trial Comparing Cold Tub Versus Cold Shower
An interest in cold-water immersion (CWI) to elicit diverse physiological effects has been prevalent for centuries. CWI typically consists of bodily exposure to water at temperatures ranging from 5-10º C for various durations. CWI has profound cultural significance in different areas of the world, such as in Scandinavian countries, and has emerged as a popular modality for its purported health-promoting effects. Individuals on social media have repeatedly advocated for CWI as a method to improve muscular recovery, enhance sleep, and increase immune and cognitive function. Because of this, companies that specialize in cold tub production have become popularized; however, individuals who are seeking a more cost-effective option are drawn toward cold showers for their preferred method of cold exposure. Despite the scarcity of rigorous research investigating the difference in effects of cold tub versus cold shower CWI, individuals on social media promoting CWI via a shower continue to praise its comparable benefits to that of a tub. Therefore, investigations of chronic CWI (utilizing both a cold tub and a cold shower) is vital.
Thus, the purpose of the proposed study is to explore the varying effects of chronic CWI on neural and cognitive function using a cold tub and a cold shower. Further, the study aims to investigate performance measures and immune measures to create a comprehensive understanding of CWI's implications on human physiology over time. The investigators hypothesize measures relating to mental performance and health will improve after 4-weeks of CWI, and there will be no difference between tub and shower immersion groups.
- Conditions
- Cold Exposure
- Being tested
- Cold Water Immersion (CWI) - Cold Tub Immersion (CI), Cold Water Immersion (CWI) - Cold Shower (CS)
- Keywords
- Cold Water Immersion, Cold Tub, Cold Shower
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Cold Water Immersion (CWI) - Cold Tub Immersion (CI)Other
Once thermoneutral procedures are complete, participants in the CI group will be seated in the cold tub and submerged into the water (10º C). The sternal notch of each participant will be used as the anatomical marker to mark submersion point. Participants will sit with both arms outstretched underwater with their backs not touching the sides of the tub. Participants with a shorter stature will be provided an underwater cushion to meet the submersion requirements. The 4-minute timer will begin once confirmation of the participants submersion level and posture is determined. Once completed, the participant will be instructed to slowly exit the tub and allowed to dry and change as necessary.
Cold Water Immersion (CWI) - Cold Shower (CS)Other
Once thermoneutral procedures are complete, participants in the CS group will be instructed to enter the research shower area in Gunter 1610. Within the shower area, the walls of the shower will be numbered from 1 to 4, with 1 defined as facing the faucet, 2 defined as 90° to the right of side 1, 3 defined as 180° from the faucet, and 4 defined as 270° to the right or 90° C to the left from side 1. Participants will be instructed to turn 90° to the right cycling through sides 1 to 4 and then back to 1 every 15 seconds prompted by the researcher. This will allow the participant to complete three full rotations in the shower during the 4-minute intervention time. The shower faucet is modified and oriented in a way where it only produces cold water (10º C) when turned on. Once completed, the participant will be instructed to slowly exit the shower and is allowed to dry and change as necessary.
| Study group | Role | What they receive |
|---|---|---|
| Cold Tub Immersion Group (CI) | Experimental | Participants will utilize the research cold tub area (10 ºC, 4-minutes), following a standardized protocol (see intervention description). Receives: Other: Cold Water Immersion (CWI) - Cold Tub Immersion (CI) |
| Cold Shower Group (CS) | Experimental | Participants will utilize the research shower area (10 ºC, 4-minutes), following a standardized protocol (see intervention description). Receives: Other: Cold Water Immersion (CWI) - Cold Shower (CS) |
| Control Group (CO) | No intervention | Participants will not participate in any cold water immersion. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Sustained Attention to Response Task (SART)
The SART is a task used to evaluate sustained attention and inhibitory control. Participants will complete the SART task on a laboratory computer. The computerized test will display 225 randomly selected numbers ranging between 1 and 9; these numbers appear in different sizes throughout the duration of the test and are displayed in white on a black screen. Participants will be instructed to respond when each number appears by pressing the space bar on the computer's keyboard while refraining from pressing the space bar when the number 3 appears. Total error score will be calculated by assessing the number of space bar presses when no key should've been pressed as well as absent presses when a key should've been pressed.
Measured: Visit 1B (Week 1) and Visit 2B (Week 4)
Alternate Use Task (AUT)
The Alternate Use Task is used to evaluate creativity and divergent thinking. The task will be derived from the original paper version of the AUT, in which an everyday object will be randomly selected and presented to the participant, and the participant will be tasked with thinking of a possible use for the presented object. Participants will be instructed to think of novel and unique uses that would deviate from traditional uses of the presented object. Participants will be given a blank sheet of paper and be granted 2-minutes to write down as many uses as possible. In this modified version of the original test, participants will be screened for originality, fluency, and flexibility.
Measured: Visit 1B (Week 1) and Visit 2B (Week 4)
Piper Fatigue Scale (PFS)
Participants will be asked to complete the Piper Fatigue Scale (PFS), a 27-question questionnaire that utilizes a Likert scale (1-10) to assess subdomains of behavioral, affective, sensory, and cognitive/mood attributes of fatigue. This version of the PFS is a subjective measure of fatigue using a 10-point Likert scale ranging from 0 - 10 with 0 indicating "No Distress" and 10 indicating "A Great Deal", "Mild" to "Severe", "Pleasant" to "Unpleasant", "Agreeable" to "Disagreeable", "Protective" to "Destructive", "Positive" to "Negative", "Normal" to "Abnormal", "Strong" to "Weak", "Awake" to "Sleepy", "Lively" to "Listless", "Refreshed" to "Tired", "Energetic" to "Unenergetic", "Patient" to "Impatient", "Relaxed" to "A Great Deal", "Exhilarated" to "Depressed", "Able to Concentrate" to "Unable to Concentrate", "Able to Remember" to "Unable to Remember", and "Able to Think Clearly" to "Unable to Think Clearly".
Measured: Visit 1B (Week 1) and Visit 2B (Week 4)
Perceived Stress Scale (PSS)
Participants will be asked to complete the Perceived Stress Scale (PSS), a classic stress assessment tool used to gauge how different situations affect feelings and perceived stress. This version of the PSS is a subjective measure of stress using a 5-point Likert scale ranging from 0 - 4 with 0 indicating "Never", 1 indicating "Almost Never", 2 indicating "Sometimes", 3 indicating "Fairly Often", and 4 indicating "Very Often".
Measured: Visit 1B (Week 1) and Visit 2B (Week 4)
Mindful Attention Awareness Scale (MAAS)
Participants will be asked to complete the Mindful Attention Awareness Scale (MAAS), a 15-item scale designed to assess the core characteristics of mindfulness. This version of the MAAS is a subjective measure of mindfulness using a 6-point Likert scale ranging from 1 - 6 with 1 indicating "Almost Always", 2 indicating "Very Frequently", 3 indicating "Somewhat Frequently", 4 indicating "Somewhat Infrequently", 5 indicating "Very Infrequently", and 6 indicating "Almost Never".
Measured: Visit 1B (Week 1) and Visit 2B (Week 4)
Heart Rate Variability (HRV)
Heart rate variability (HRV) will be analyzed to determine the fluctuation in the time intervals between adjacent heartbeats to assess autonomic regulation of the heart. Resting HR and HRV were measured using the electrocardiograph (GE CASE Exercise Testing System Version 6.0, Chicago, Illinois). To measure HRV, the root mean square successive difference method (RMSSD) was used with the 10-second electrocardiogram reading. Based on the outcome of this assessment, participants with SDNN values below 50 ms will be classified as unhealthy, 50-100 ms will be classified as having compromised health, and above 100 ms will be classified as healthy.
Measured: Visit 1B (Week 1) and Visit 2B (Week 4)
Pittsburgh Sleep Quality Index (PSQI)
Participants will be asked to complete the Pittsburgh Sleep Quality Index (PSQI). The PSQI is a 19-question self-reported sleep quality screening tool broken up into 7 subcategories for scoring, such as subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction.
Measured: Visit 1A (Week 1) and Visit 2A (Week 4)
Serum Analysis - Brain-Derived Neurotrophic Factor (BDNF)
Approximately 40mL of whole blood will be collected into serum separator tubes (Beckton Dickinson, East Rutherford, NJ, USA), allowed to clot for 30-minutes at room temperature, then centrifuged at 2000 RPM for 15 min. The serum will be pipetted into 1.5 mL microcentrifuge tubes (Eppendorf AG, Hamburg, Germany) and immediately stored in a -80 °C freezer. Serum concentrations of BDNF (Sigma-Aldrich, St. Louis, MO, USA) will be determined with a commercially available enzyme-linked immunosorbent assays. Microplates will be read with an ELx800 BioTek microplate reader (BioTek Instruments, Inc., Winooski, VT, USA) at the recommended wavelength of 450 nanometers.
Measured: Visit 1A (Week 1) and Visit 2A (Week 4)
Secondary outcomes (7)
Anthropometric Measures - Height
Height will be obtained in centimeters (cm)( using a stadiometer SECA 220 (Chino, California, USA).
Measured: Visit 1A (Week 1) and Visit 2A (Week 4)
Anthropometric Measures - Weight
Weight will be obtained in kilograms (kg) using a Detecto standing digital scale (Webb City, Missouri, USA).
Measured: Visit 1A (Week 1) and Visit 2A (Week 4)
Anthropometric Measures - Lean Body Mass
Lean body mass (LBM) will be measured in kilograms and evaluated using air displacement plethysmography using a calibrated BOD POD (COSMED USA Inc., Concord, CA).
Measured: Visit 1A (Week 1) and Visit 2A (Week 4)
Anthropometric Measures - Body Fat Percentage
Body fat percentage (BF%) will be measured as a percentage of estimated body fat relative to total body mass and evaluated using air displacement plethysmography using a calibrated BOD POD (COSMED USA Inc., Concord, CA).
Measured: Visit 1A (Week 1) and Visit 2A (Week 4)
Hydration
A refractometer (Atago, Tokyo, JPN) will be used to evaluate urine specific gravity with a dehydration cutoff point set to ≥1.020 mg/dL. Dehydrated participants will be given time to hydrate. If dehydration persisted, participants will be asked to reschedule the session. After verbal compliance and hydration status are confirmed, participants will proceed with the study's procedures.
Measured: Visit 1A (Week 1) and Visit 2A (Week 4)
Qualitative Assessment
Participants will be asked to complete a qualitative questionnaire to indicate their perceptions of cold water therapy. The purpose of this assessment is to see if participants' perceptions change throughout the study. Further, this questionnaire allows participants to provide any extra qualitative feedback to gain a comprehensive insight on their chronic CWI experience. No scale is used in this survey; however, participants are given the opportunity to report their perceptions of cold immersion using the following choices: increases energy, reduces anxiety, improves sleep, improves mental health, improves physical health, improves immune system, reduces soreness or pain, or other [text response].
Measured: Visit 1A (Week 1) and Visit 2A (Week 4)
Visual Analogue Scale (VAS) of Discomfort
Participants will be assessed on their subjective ratings of discomfort as they acclimate to the cold exposure. During cold-water immersion visits (at the 1-minute mark of immersion, participants will be presented with the Visual Analogue Scale (VAS) of Discomfort, a modified version of a 0-10 item pain scale. This version of the VAS is a subjective measure of discomfort using a 11-point Likert scale ranging from 0 - 10 with 0 indicating "No Discomfort" and 10 indicating "Maximal Discomfort." Because there are twelve total water immersion visits (four weeks, three days per week), the VAS is used twelve times in total.
Measured: Every water immersion visit (days 1-12; 3 days per week for 4 weeks)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Oct 2024
- Study start10 Oct 2024
- Primary completion1 Dec 2025
- Study completion1 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cold ExposureStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Parallel, randomized design, matched for biological age
- Masking
- None (open label)
- Enrolment
- 36 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Northern Colorado
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Laura Stewart, University of Northern Colorado
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06667193
- Sponsor's protocol ID
- 2404058903
- Status last verified
- Sep 2026
- First submitted
- 10 Oct 2024
- Last updated
- 30 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: We will make all study documents available by reasonable request (Laura.stewart@unco.edu) up to 3 years after data collection is complete.
Study at a glance
From the registry record, last updated by the sponsor on 30 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Cold-Water Immersion's Effects on Physical and Mental Health: A 4-Week Randomized Trial Comparing Cold Tub Versus Cold Shower
- ClinicalTrials.gov ID
- NCT06667193
- Acronym / sponsor ID
- 2404058903
- Conditions
- Cold Exposure
- Keywords
- Cold Water Immersion, Cold Tub, Cold Shower
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 36 participants (actual)
- Lead sponsor
- University of Northern ColoradoUniversity, hospital or other
- Study start
- 10 Oct 2024 (actual)
- Primary completion
- 1 Dec 2025 (actual)
- Study completion
- 1 Dec 2025 (actual)
- First posted
- 31 Oct 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
An interest in cold-water immersion (CWI) to elicit diverse physiological effects has been prevalent for centuries. CWI typically consists of bodily exposure to water at temperatures ranging from 5-10º C for various durations. CWI has profound cultural significance in different areas of the world, such as in Scandinavian countries, and has emerged as a popular modality for its purported health-promoting effects. Individuals on social media have repeatedly advocated for CWI as a method to improve muscular recovery, enhance sleep, and increase immune and cognitive function. Because of this, companies that specialize in cold tub production have become popularized; however, individuals who are seeking a more cost-effective option are drawn toward cold showers for their preferred method of cold exposure. Despite the scarcity of rigorous research investigating the difference in effects of cold tub versus cold shower CWI, individuals on social media promoting CWI via a shower continue to praise its comparable benefits to that of a tub. Therefore, investigations of chronic CWI (utilizing both a cold tub and a cold shower) is vital.
Thus, the purpose of the proposed study is to explore the varying effects of chronic CWI on neural and cognitive function using a cold tub and a cold shower. Further, the study aims to investigate performance measures and immune measures to create a comprehensive understanding of CWI's implications on human physiology over time. The investigators hypothesize measures relating to mental performance and health will improve after 4-weeks of CWI, and there will be no difference between tub and shower immersion groups.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
- Model description
- Parallel, randomized design, matched for biological age
| Arm | Type | Receives |
|---|---|---|
| Cold Tub Immersion Group (CI) | Experimental | Other: Cold Water Immersion (CWI) - Cold Tub Immersion (CI)Participants will utilize the research cold tub area (10 ºC, 4-minutes), following a standardized protocol (see intervention description). |
| Cold Shower Group (CS) | Experimental | Other: Cold Water Immersion (CWI) - Cold Shower (CS)Participants will utilize the research shower area (10 ºC, 4-minutes), following a standardized protocol (see intervention description). |
| Control Group (CO) | No intervention | –Participants will not participate in any cold water immersion. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Healthy volunteers
- Aged 18-45
Key exclusion criteria (4 listed)
- Current holds a cold water exposure routine (≥3 sessions in the last month, consisting of ≥4 minutes per immersion)
- Currently pregnant of planning to become pregnant
- Chronic use of anti-inflammatory medication
- Prior history of chronic disease conditions: Cardiovascular Disease, Diabetes, Cancer, Raynaud's Disease, or severe/untreated anxiety or depression
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Cold Water Immersion (CWI) - Cold Tub Immersion (CI)Once thermoneutral procedures are complete, participants in the CI group will be seated in the cold tub and submerged into the water (10º C). The sternal notch of each participant will be used as the anatomical marker to mark submersion point. Participants will sit with both arms outstretched underwater with their backs not touching the sides of the tub. Participants with a shorter stature will be provided an underwater cushion to meet the submersion requirements. The 4-minute timer will begin once confirmation of the participants submersion level and posture is determined. Once completed, the participant will be instructed to slowly exit the tub and allowed to dry and change as necessary. | Other | Cold Tub Immersion Group (CI) |
| Cold Water Immersion (CWI) - Cold Shower (CS)Once thermoneutral procedures are complete, participants in the CS group will be instructed to enter the research shower area in Gunter 1610. Within the shower area, the walls of the shower will be numbered from 1 to 4, with 1 defined as facing the faucet, 2 defined as 90° to the right of side 1, 3 defined as 180° from the faucet, and 4 defined as 270° to the right or 90° C to the left from side 1. Participants will be instructed to turn 90° to the right cycling through sides 1 to 4 and then back to 1 every 15 seconds prompted by the researcher. This will allow the participant to complete three full rotations in the shower during the 4-minute intervention time. The shower faucet is modified and oriented in a way where it only produces cold water (10º C) when turned on. Once completed, the participant will be instructed to slowly exit the shower and is allowed to dry and change as necessary. | Other | Cold Shower Group (CS) |
Primary outcome
Sustained Attention to Response Task (SART)
Time frame: Visit 1B (Week 1) and Visit 2B (Week 4)
The SART is a task used to evaluate sustained attention and inhibitory control. Participants will complete the SART task on a laboratory computer. The computerized test will display 225 randomly selected numbers ranging between 1 and 9; these numbers appear in different sizes throughout the duration of the test and are displayed in white on a black screen. Participants will be instructed to respond when each number appears by pressing the space bar on the computer's keyboard while refraining from pressing the space bar when the number 3 appears. Total error score will be calculated by assessing the number of space bar presses when no key should've been pressed as well as absent presses when a key should've been pressed.
Alternate Use Task (AUT)
Time frame: Visit 1B (Week 1) and Visit 2B (Week 4)
The Alternate Use Task is used to evaluate creativity and divergent thinking. The task will be derived from the original paper version of the AUT, in which an everyday object will be randomly selected and presented to the participant, and the participant will be tasked with thinking of a possible use for the presented object. Participants will be instructed to think of novel and unique uses that would deviate from traditional uses of the presented object. Participants will be given a blank sheet of paper and be granted 2-minutes to write down as many uses as possible. In this modified version of the original test, participants will be screened for originality, fluency, and flexibility.
Piper Fatigue Scale (PFS)
Time frame: Visit 1B (Week 1) and Visit 2B (Week 4)
Participants will be asked to complete the Piper Fatigue Scale (PFS), a 27-question questionnaire that utilizes a Likert scale (1-10) to assess subdomains of behavioral, affective, sensory, and cognitive/mood attributes of fatigue. This version of the PFS is a subjective measure of fatigue using a 10-point Likert scale ranging from 0 - 10 with 0 indicating "No Distress" and 10 indicating "A Great Deal", "Mild" to "Severe", "Pleasant" to "Unpleasant", "Agreeable" to "Disagreeable", "Protective" to "Destructive", "Positive" to "Negative", "Normal" to "Abnormal", "Strong" to "Weak", "Awake" to "Sleepy", "Lively" to "Listless", "Refreshed" to "Tired", "Energetic" to "Unenergetic", "Patient" to "Impatient", "Relaxed" to "A Great Deal", "Exhilarated" to "Depressed", "Able to Concentrate" to "Unable to Concentrate", "Able to Remember" to "Unable to Remember", and "Able to Think Clearly" to "Unable to Think Clearly".
Perceived Stress Scale (PSS)
Time frame: Visit 1B (Week 1) and Visit 2B (Week 4)
Participants will be asked to complete the Perceived Stress Scale (PSS), a classic stress assessment tool used to gauge how different situations affect feelings and perceived stress. This version of the PSS is a subjective measure of stress using a 5-point Likert scale ranging from 0 - 4 with 0 indicating "Never", 1 indicating "Almost Never", 2 indicating "Sometimes", 3 indicating "Fairly Often", and 4 indicating "Very Often".
Mindful Attention Awareness Scale (MAAS)
Time frame: Visit 1B (Week 1) and Visit 2B (Week 4)
Participants will be asked to complete the Mindful Attention Awareness Scale (MAAS), a 15-item scale designed to assess the core characteristics of mindfulness. This version of the MAAS is a subjective measure of mindfulness using a 6-point Likert scale ranging from 1 - 6 with 1 indicating "Almost Always", 2 indicating "Very Frequently", 3 indicating "Somewhat Frequently", 4 indicating "Somewhat Infrequently", 5 indicating "Very Infrequently", and 6 indicating "Almost Never".
Heart Rate Variability (HRV)
Time frame: Visit 1B (Week 1) and Visit 2B (Week 4)
Heart rate variability (HRV) will be analyzed to determine the fluctuation in the time intervals between adjacent heartbeats to assess autonomic regulation of the heart. Resting HR and HRV were measured using the electrocardiograph (GE CASE Exercise Testing System Version 6.0, Chicago, Illinois). To measure HRV, the root mean square successive difference method (RMSSD) was used with the 10-second electrocardiogram reading. Based on the outcome of this assessment, participants with SDNN values below 50 ms will be classified as unhealthy, 50-100 ms will be classified as having compromised health, and above 100 ms will be classified as healthy.
Pittsburgh Sleep Quality Index (PSQI)
Time frame: Visit 1A (Week 1) and Visit 2A (Week 4)
Participants will be asked to complete the Pittsburgh Sleep Quality Index (PSQI). The PSQI is a 19-question self-reported sleep quality screening tool broken up into 7 subcategories for scoring, such as subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction.
Serum Analysis - Brain-Derived Neurotrophic Factor (BDNF)
Time frame: Visit 1A (Week 1) and Visit 2A (Week 4)
Approximately 40mL of whole blood will be collected into serum separator tubes (Beckton Dickinson, East Rutherford, NJ, USA), allowed to clot for 30-minutes at room temperature, then centrifuged at 2000 RPM for 15 min. The serum will be pipetted into 1.5 mL microcentrifuge tubes (Eppendorf AG, Hamburg, Germany) and immediately stored in a -80 °C freezer. Serum concentrations of BDNF (Sigma-Aldrich, St. Louis, MO, USA) will be determined with a commercially available enzyme-linked immunosorbent assays. Microplates will be read with an ELx800 BioTek microplate reader (BioTek Instruments, Inc., Winooski, VT, USA) at the recommended wavelength of 450 nanometers.
7 secondary outcomes
Anthropometric Measures - Height
Time frame: Visit 1A (Week 1) and Visit 2A (Week 4)
Anthropometric Measures - Weight
Time frame: Visit 1A (Week 1) and Visit 2A (Week 4)
Anthropometric Measures - Lean Body Mass
Time frame: Visit 1A (Week 1) and Visit 2A (Week 4)
Anthropometric Measures - Body Fat Percentage
Time frame: Visit 1A (Week 1) and Visit 2A (Week 4)
Hydration
Time frame: Visit 1A (Week 1) and Visit 2A (Week 4)
Qualitative Assessment
Time frame: Visit 1A (Week 1) and Visit 2A (Week 4)
Visual Analogue Scale (VAS) of Discomfort
Time frame: Every water immersion visit (days 1-12; 3 days per week for 4 weeks)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Sep 2026.
- Individual participant dataSharing planned: Yes. We will make all study documents available by reasonable request (Laura.stewart@unco.edu) up to 3 years after data collection is complete.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Cold Water Immersion (CWI) - Cold Tub Immersion (CI) and Cold Water Immersion (CWI) - Cold Shower (CS) in people with Cold Exposure, run by University of Northern Colorado at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 30 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Sustained Attention to Response Task (SART) (time frame: Visit 1B (Week 1) and Visit 2B (Week 4)). The study lists 8 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Sep 2026.