Cardiovascular Reactivity to Physical Stress (REACT)

March 8, 2026 updated by: Ann-Katrin Grotle, Western Norway University of Applied Sciences

Cardiovascular Reactivity to Physical Stress: Strategies and Mechanisms

It is well-accepted that an exaggerated blood pressure (BP) response to physical stress has a prognostic value, indicating a higher cardiovascular risk (e.g., sudden cardiac death, myocardial infarction, future hypertension, and left ventricular hypertrophy). However, there is a limited understanding of the underlying mechanisms and therapuetic strategies modulating this response. Therefore, this pilot project aims to explore whether one session of low-volume high-intensity interval training (low-volume HIIT) or combined intermittent heat and cold bath (sauna+cold bath) can decrease BP responses to physical stress. Furthermore, the secondary goal is to investigate whether one brief session learning about positive stress expectations magnifies the decrease in BP following low-volume HIIT and sauna+ cold bath.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
45

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Norway
    • Vestland
      • Bergen, Vestland, Norway, 5063
        • Western Norway University of Applied Sciences

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Male or female between 18 to 50 years
  • Non-smoker.
  • Non-obese (<30 kg/m2).
  • Able to walk on a treadmill and cycle on a stationary bike without problems.
  • No or little (frequency < 2 times per month) experience swimming with sauna and cold water.
  • Proficient in Norwegian and able to provide informed consent.

Exclusion Criteria:

  • Current or previous regular smoker
  • Addictions to alcohol or illegal drugs
  • Diagnosed with cardiovascular, respiratory, metabolic, or autoimmune diseases
  • Taking prescription medication with known cardiovascular effects
  • Judgment by a medical provider that exercise, heat therapy, or hydrotherapy poses an undue burden or risk.
  • Cognitive or psychiatric impairment
  • Lack of proficiency in Norwegian language oral or writing skills that will hamper the ability to participate in the interventions and fill out questionnaires.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Positive stress education (PSE)
This intervention will consist of standardized information about the relationships between expectations and the stress response. Using the CATS as a theoretical framework, the participants will be explained that when people face stressors, i.e., pain, heat, and cold water, the expectations about handling the situation will influence both the experience (e.g., pain) and the physiological stress response.
Other: Low-volume high intensity exercise
This intervention will consist of 10 x 10-second interval sprints on a stationary bicycle interspersed with 50-second breaks between repetitions. The cycle resistance will be adjusted to the level equaling the highest power output, which will be determined during warm-up sprints.
Other: Combined intermittent sauna and cold water bath (sauna+cold bath).
This intervention will consist of 3x10 min bouts in the dry sauna interspersed with 2x 60 seconds of cold water immersion up to the neck.
Sham Comparator: Neutral control
To control for the PSE intervention, the participants will receive 15 min of neutral information about the effects of physical exercise on cardiovascular fitness.
Other: Low-volume high intensity exercise
This intervention will consist of 10 x 10-second interval sprints on a stationary bicycle interspersed with 50-second breaks between repetitions. The cycle resistance will be adjusted to the level equaling the highest power output, which will be determined during warm-up sprints.
Other: Combined intermittent sauna and cold water bath (sauna+cold bath).
This intervention will consist of 3x10 min bouts in the dry sauna interspersed with 2x 60 seconds of cold water immersion up to the neck.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Blood pressure (unit: mmHg) response to laboratory stressors
Time Frame: Assessment will be completed before intervention and approximately 30 minutes after intervention
Response will be calculated as the change from baseline to peak. Stressors employed include handgrip exercise, post-exercise ischemia, and cold pressor test.
Assessment will be completed before intervention and approximately 30 minutes after intervention

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Resting blood pressure (mmHg).
Time Frame: Assessment will be completed before intervention and approximately 30 minutes after intervention
Assessment will be completed before intervention and approximately 30 minutes after intervention
Endothelial function (% dilation)
Time Frame: Assessment will be completed before intervention and approximately 30 minutes after intervention.
Endothelial function will be assessed using the flow-mediated dilation technique following current guidelines.
Assessment will be completed before intervention and approximately 30 minutes after intervention.
Subjective ratings of expectancies (point score).
Time Frame: Assessment will be completed before intervention and approximately 30 minutes after intervention.
Stress, pain, heat, and cold response expectancies will be assessed with single questions specifically targeted to the interventions and experimental tests using a Numeric Rating Scale (NRS) ranging from 0 = no stress, no pain, no discomfort (heat, cold) at all to 10 = worst possible pain, stress, heat/cold discomfort.
Assessment will be completed before intervention and approximately 30 minutes after intervention.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Western Norway University of Applied Sciences

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 19, 2024

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 1, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 1, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 11, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 11, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 19, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 11, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 8, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2688791

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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