Elevated Blood PressureExHTNCT06348225
Post-exercise Hot Water Immersion to Improve Overnight Blood Pressure
A study testing Exercise and Heat Therapy in people with Elevated Blood Pressure, run by Providence College at 1 site in United States.
Trial summary
The goal of this clinical trial is to test whether putting a participant's legs in a hot bath after exercise improves blood pressure in people with higher blood pressure. . The main questions it aims to answer are: Whether exercise alone, hot water leg bath alone, or both treatments together cause blood pressure to be… Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Elevated Blood Pressure
- What is being tested?
- Exercise and Heat Therapy
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jul 2024to 30 Apr 2026
- 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 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- resting blood pressure >120/80 mmHg; measured at screening visit
- BMI between 18-39.9
- capable of walking 30 min at a moderate intensity on a treadmill
Who cannot join
- diagnosed hypertension
- taking antihypertensive medications
- history of heat injury or heat illness
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Post-exercise Hot Water Immersion to Improve Blood Pressure Control
The goal of this clinical trial is to test whether putting a participant's legs in a hot bath after exercise improves blood pressure in people with higher blood pressure.
. The main questions it aims to answer are:
Read more
- Whether exercise alone, hot water leg bath alone, or both treatments together cause blood pressure to be lower during sleep.
- If there are any changes in heart rhythm or blood vessel health after exercise, hot water leg bath, or the two treatments together that relate to changes in blood pressure.
Participants will complete four different trials:
- 30 minutes of walking with a 45-minute lukewarm leg bath after
- 30 minutes of walking with a 45-minute hot leg bath after
- 45 minutes of a hot leg bath with no exercise
- A day with no exercise or leg bath Researchers will look at heart rhythm, blood vessels, and blood pressure after each of these trials to see if there are differences, and if exercise and heat together can improve heart health more than exercise or heat alone.
Read the detailed description
In 2017, the American Heart Association updated standards for diagnosing hypertension, while emphasizing the need for lifestyle modification in the early stages of blood pressure elevation. Using these updated criteria, approximately 1/3 of U.S. adults have hypertension, but few are able to improve blood pressure through diet and exercise and often progress to more severe disease states. Novel interventions to promote blood pressure reduction in mild hypertension are needed to attenuate or prevent this progression to more severe hypertension. Heat therapy, the repeated application of passive heat through hot water immersion, has gained recent attention for promising blood pressure reduction and improvement in cardiovascular health. Preliminary work combining exercise and hot water leg immersion indicates improved overnight blood pressure in individuals with elevated blood pressure, but the magnitude and mechanisms of this improvement require further study.
It is unknown whether the decrease in blood pressure following post-exercise heat exposure results from changes in systemic regulation (autonomic nervous system function, measured through heart rate variability), local factors (improved blood vessel function, measured through flow-mediated dilation), or both. The goal of the proposed research is to examine the impact of exercise alone (30 minutes of treadmill walking), hot water immersion alone (45 minutes in a leg bath set to 42°C), and combined exercise + hot water immersion (30 minutes treadmill walking followed by 45 minutes in a 42°C leg bath) on nocturnal blood pressure, autonomic function, and blood vessel function in individuals with elevated blood pressure. This goal will be addressed with the following specific aims:
Aim 1. To examine the impact of exercise, hot water leg immersion, or combined exercise + hot water immersion on overnight blood pressure in individuals with elevated blood pressure. The researchers hypothesize that the combination of exercise and hot water immersion will result in reduced systolic and diastolic blood pressure through 12 hours post-exercise as compared to baseline or either standalone treatment.
Aim 2. To examine changes in autonomic function, as measured by heart rate variability (HRV) following exercise, leg heating, or combined therapies. The researchers hypothesize that combined exercise and hot water immersion will result in higher HRV (indicating improved autonomic balance) compared to baseline measures.
Aim 3. To examine changes in blood vessel (endothelial) function, measured using flow-mediated dilation, following exercise, leg heating, or combined therapies. The researchers hypothesize that combined exercise and hot water immersion will result in a higher flow-mediated dilation (indicating improved blood vessel relaxation) compared to baseline or either standalone intervention.
The results of this study have important health implications in the treatment of hypertension using lifestyle interventions for the millions of Americans with elevated blood pressure or hypertension. The findings have the potential to improve non-pharmacological treatment of hypertension by developing an exercise and heat exposure protocol that is cost-effective, easily implemented, and results in substantially reduced blood pressure and improved cardiovascular risk profile.
- Conditions
- Elevated Blood Pressure
- Being tested
- Exercise, Heat Therapy, Sham leg bath
- Keywords
- exercise, heat therapy
- Medical subject headings
- Hypertension, Motor Activity, Hyperthermia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ExerciseBehavioural
Also called Treadmill walking
Participants will walk on a treadmill for 30 minutes at 55-60% of heart rate reserve. The treadmill will be set at 2mph and 2% grade, then be adjusted in the first 5 minutes to achieve target heart rate.
Heat TherapyOther
Also called hot leg bath
Participants will place their legs in a deep leg bath (mid-calf) set to 42C for 45 minutes.
Sham leg bathOther
Also called lukewarm leg bath
Participants will place their legs in a deep leg bath (mid-calf) set to 36C for 45 minutes.
| Study group | Role | What they receive |
|---|---|---|
| Exercise + Heat Therapy | Experimental | This treatment will include exercise (treadmill walking) and hot leg bath. Receives: Behavioral: Exercise; Other: Heat Therapy |
| Heat Therapy | Experimental | This treatment will only include the hot leg bath (no exercise). Receives: Other: Heat Therapy |
| Exercise | Active comparator | This treatment will include exercise (treadmill walking) followed by a sham leg bath. Receives: Behavioral: Exercise; Other: Sham leg bath |
| Control | No intervention | Participants will refrain from exercise or heat exposure for at least 24 hours, and perform all study analyses for a control comparison. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Ambulatory blood pressure
Welch-Allyn ambulatory blood pressure monitor placed on the arm after treatment
Measured: 24 hours post-treatment
Heart Rate Variability
3-lead ECG with paced breathing measured post-treatment
Measured: 30-60 min post-treatment
Flow-mediated dilation
Measure of endothelial function in the brachial artery (arm), change in blood vessel diameter following a 5-minute blood flow occlusion and release
Measured: 30-60 min post-treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Apr 2024
- Study start1 Jul 2024
- Primary completion10 Apr 2026
- Study completion30 Apr 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Elevated Blood PressureStudies 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- A repeated-measures design will be used with all participants completing the three acute interventions (exercise, heat, or exercise + heat) as well as a control day.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Providence College
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Brett Romano Ely, Providence College
- Investigators
- Brett R Ely, PhD, Principal investigator, Providence College
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06348225
- Sponsor's protocol ID
- FY24-10
- Acronym
- ExHT
- Status last verified
- May 2026
- First submitted
- 28 Mar 2024
- Last updated
- 1 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: The current plan is to share only compiled data with other researchers if requested.
Study at a glance
From the registry record, last updated by the sponsor on 1 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Post-exercise Hot Water Immersion to Improve Blood Pressure Control
- ClinicalTrials.gov ID
- NCT06348225
- Acronym / sponsor ID
- ExHT / FY24-10
- Conditions
- Elevated Blood Pressure
- Keywords
- exercise, heat therapy
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Providence CollegeUniversity, hospital or other
- Study start
- 1 Jul 2024 (actual)
- Primary completion
- 10 Apr 2026 (actual)
- Study completion
- 30 Apr 2026 (actual)
- First posted
- 4 Apr 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.
The goal of this clinical trial is to test whether putting a participant's legs in a hot bath after exercise improves blood pressure in people with higher blood pressure.
. The main questions it aims to answer are:
- Whether exercise alone, hot water leg bath alone, or both treatments together cause blood pressure to be lower during sleep.
- If there are any changes in heart rhythm or blood vessel health after exercise, hot water leg bath, or the two treatments together that relate to changes in blood pressure.
Participants will complete four different trials:
- 30 minutes of walking with a 45-minute lukewarm leg bath after
- 30 minutes of walking with a 45-minute hot leg bath after
- 45 minutes of a hot leg bath with no exercise
- A day with no exercise or leg bath Researchers will look at heart rhythm, blood vessels, and blood pressure after each of these trials to see if there are differences, and if exercise and heat together can improve heart health more than exercise or heat alone.
Detailed description
In 2017, the American Heart Association updated standards for diagnosing hypertension, while emphasizing the need for lifestyle modification in the early stages of blood pressure elevation. Using these updated criteria, approximately 1/3 of U.S. adults have hypertension, but few are able to improve blood pressure through diet and exercise and often progress to more severe disease states. Novel interventions to promote blood pressure reduction in mild hypertension are needed to attenuate or prevent this progression to more severe hypertension. Heat therapy, the repeated application of passive heat through hot water immersion, has gained recent attention for promising blood pressure reduction and improvement in cardiovascular health. Preliminary work combining exercise and hot water leg immersion indicates improved overnight blood pressure in individuals with elevated blood pressure, but the magnitude and mechanisms of this improvement require further study.
It is unknown whether the decrease in blood pressure following post-exercise heat exposure results from changes in systemic regulation (autonomic nervous system function, measured through heart rate variability), local factors (improved blood vessel function, measured through flow-mediated dilation), or both. The goal of the proposed research is to examine the impact of exercise alone (30 minutes of treadmill walking), hot water immersion alone (45 minutes in a leg bath set to 42°C), and combined exercise + hot water immersion (30 minutes treadmill walking followed by 45 minutes in a 42°C leg bath) on nocturnal blood pressure, autonomic function, and blood vessel function in individuals with elevated blood pressure. This goal will be addressed with the following specific aims:
Aim 1. To examine the impact of exercise, hot water leg immersion, or combined exercise + hot water immersion on overnight blood pressure in individuals with elevated blood pressure. The researchers hypothesize that the combination of exercise and hot water immersion will result in reduced systolic and diastolic blood pressure through 12 hours post-exercise as compared to baseline or either standalone treatment.
Aim 2. To examine changes in autonomic function, as measured by heart rate variability (HRV) following exercise, leg heating, or combined therapies. The researchers hypothesize that combined exercise and hot water immersion will result in higher HRV (indicating improved autonomic balance) compared to baseline measures.
Aim 3. To examine changes in blood vessel (endothelial) function, measured using flow-mediated dilation, following exercise, leg heating, or combined therapies. The researchers hypothesize that combined exercise and hot water immersion will result in a higher flow-mediated dilation (indicating improved blood vessel relaxation) compared to baseline or either standalone intervention.
The results of this study have important health implications in the treatment of hypertension using lifestyle interventions for the millions of Americans with elevated blood pressure or hypertension. The findings have the potential to improve non-pharmacological treatment of hypertension by developing an exercise and heat exposure protocol that is cost-effective, easily implemented, and results in substantially reduced blood pressure and improved cardiovascular risk profile.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 4
- Model description
- A repeated-measures design will be used with all participants completing the three acute interventions (exercise, heat, or exercise + heat) as well as a control day.
| Arm | Type | Receives |
|---|---|---|
| Exercise + Heat Therapy | Experimental | Behavioral: Exercise, Other: Heat TherapyThis treatment will include exercise (treadmill walking) and hot leg bath. |
| Heat Therapy | Experimental | Other: Heat TherapyThis treatment will only include the hot leg bath (no exercise). |
| Exercise | Active comparator | Behavioral: Exercise, Other: Sham leg bathThis treatment will include exercise (treadmill walking) followed by a sham leg bath. |
| Control | No intervention | –Participants will refrain from exercise or heat exposure for at least 24 hours, and perform all study analyses for a control comparison. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- resting blood pressure >120/80 mmHg; measured at screening visit
- BMI between 18-39.9
- capable of walking 30 min at a moderate intensity on a treadmill
Key exclusion criteria (3 listed)
- diagnosed hypertension
- taking antihypertensive medications
- history of heat injury or heat illness
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 |
|---|---|---|
| ExerciseAlso: Treadmill walkingParticipants will walk on a treadmill for 30 minutes at 55-60% of heart rate reserve. The treadmill will be set at 2mph and 2% grade, then be adjusted in the first 5 minutes to achieve target heart rate. | Behavioural | Exercise, Exercise + Heat Therapy |
| Heat TherapyAlso: hot leg bathParticipants will place their legs in a deep leg bath (mid-calf) set to 42C for 45 minutes. | Other | Exercise + Heat Therapy, Heat Therapy |
| Sham leg bathAlso: lukewarm leg bathParticipants will place their legs in a deep leg bath (mid-calf) set to 36C for 45 minutes. | Other | Exercise |
Primary outcome
Ambulatory blood pressure
Time frame: 24 hours post-treatment
Welch-Allyn ambulatory blood pressure monitor placed on the arm after treatment
Heart Rate Variability
Time frame: 30-60 min post-treatment
3-lead ECG with paced breathing measured post-treatment
Flow-mediated dilation
Time frame: 30-60 min post-treatment
Measure of endothelial function in the brachial artery (arm), change in blood vessel diameter following a 5-minute blood flow occlusion and release
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 1 Jun 2026.
- Individual participant dataSharing planned: No. The current plan is to share only compiled data with other researchers if requested.
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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.
Brett R Ely, PhD principal investigator
Providence College
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Exercise and Heat Therapy in people with Elevated Blood Pressure, run by Providence College 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 3 inclusion and 3 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 1 Jun 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?
Ambulatory blood pressure (time frame: 24 hours post-treatment). The study lists 3 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 1 Jun 2026.