Blood Pressure, Stress, Physiological
Conditions
Keywords
Cardiovascular reactivity, Neural control of blood pressure, Metaboreflex, Cold pressor response
Brief summary
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.
Interventions
OTHERLow-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.
OTHERCombined 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.
Sponsors
Western Norway University of Applied Sciences
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
Combined randomized controlled trial with two parallel groups
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Blood pressure (unit: mmHg) response to laboratory stressors | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Resting blood pressure (mmHg). | Assessment will be completed before intervention and approximately 30 minutes after intervention | — |
| Endothelial function (% dilation) | 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. |
| Subjective ratings of expectancies (point score). | 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. |
Countries
Norway
Outcome results
None listed