Recruiting

Finnish Sauna Therapy

Sponsor:

Brigham Young University

Code:

NCT07847424

Conditions

Physical Inactivity

Vascular Dysfunction

Skeletal Muscle Atrophy

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Interventions

Sauna

Reduced Physical Activity

Study Details

Brief summary:

The purpose of this randomized controlled trial is to determine whether daily Finnish dry sauna therapy attenuates the adverse cardiovascular, muscular, and metabolic effects of seven days of experimentally reduced physical activity in healthy adults.

Participants will be randomized to one of three groups: (1) maintained habitual physical activity with daily sauna therapy, (2) reduced physical activity with daily room-temperature sauna visits (control), or (3) reduced physical activity with daily sauna therapy. Reduced physical activity will be achieved by decreasing daily step count to approximately 1,000 steps per day with the assistance of a power wheelchair.

Outcome measures include vascular endothelial function, exercise tolerance, muscle protein synthesis, body composition, blood pressure, glucose regulation, and physiological responses to heat exposure. The study will determine whether passive heat therapy can serve as a practical intervention to preserve cardiometabolic health during short periods of reduced mobility.

Conditions

Physical Inactivity

Vascular Dysfunction

Skeletal Muscle Atrophy

Study ID

NCT07847424

Start date

Jan 1, 2026

Status verified date

Sep, 2026

Completion date

May, 2027

Anticipated

Primary completion date

Jan, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Adults aged 18 years or older
  • Healthy men and premenopausal women
  • Able and willing to provide written informed consent
  • Able to perform knee-extension cycling exercise
  • Stable habitual physical activity for at least 3 months before enrollment
  • Pass the American College of Sports Medicine (ACSM) Preparticipation Health Screening
  • Not currently taking medications known to affect cardiovascular function (e.g., antihypertensive medications or beta-blockers)
  • No regular sauna or hot-tub use (fewer than six exposures during the previous 2 months)
  • Willing and able to comply with all study procedures, including temporary reduction of physical activity, daily sauna visits, physiological testing, and follow-up assessments

Exclusion Criteria:

  • Younger than 18 years of age
  • Failure to pass the ACSM Preparticipation Health Screening
  • Unable or unwilling to perform exercise testing
  • Current cigarette or marijuana use
  • Pregnant or planning to become pregnant during the study
  • History or current diagnosis of cardiovascular disease, metabolic disease, or cognitive impairment
  • Use of medications known to influence cardiovascular function or exercise tolerance (e.g., antihypertensive medications or beta-blockers)
  • Regular sauna or hot-tub use (six or more exposures during the previous 2 months)
  • History of heat-related illness
  • Any condition that, in the opinion of the investigators, would interfere with safe participation or interpretation of study results
  • Inability to understand the study procedures or provide informed consent

Study Design

Enrollment

60 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

experimental: Habitual Physical Activity + Sauna

Participants will maintain their habitual level of physical activity for seven consecutive days while undergoing one supervised Finnish dry sauna session each day. Sauna treatments will consist of standard Finnish dry sauna exposure according to the study protocol. Participants will undergo comprehensive cardiovascular, muscular, metabolic, and physiological assessments before and after the intervention.

sham comparator: Reduced Physical Activity + Room-Temperature Sauna (Control)

Participants will reduce daily physical activity to approximately 1,000 steps per day for seven consecutive days with assistance from a power wheelchair. Participants will attend daily room-temperature sauna sessions that replicate the timing and environment of the sauna intervention without therapeutic heat exposure. Comprehensive outcome assessments will be completed before and after the intervention.

experimental: Reduced Physical Activity + Dry Sauna

Participants will reduce daily physical activity to approximately 1,000 steps per day for seven consecutive days with assistance from a power wheelchair while also completing one supervised Finnish dry sauna session each day. Outcome measures will be assessed before and after the intervention to determine whether heat therapy attenuates the adverse physiological effects of reduced physical activity.

Interventions

Sauna

Participants will complete one supervised dry sauna session each day for seven consecutive days. Sauna exposure will be delivered according to the study protocol using a standard Finnish dry sauna.

Reduced Physical Activity

Participants will reduce daily step count to approximately 1,000 steps per day for seven consecutive days. A power wheelchair will be used to assist participants in minimizing ambulation while maintaining normal daily activities.

Primary outcome measure

  • Femoral artery endothelial function [ Time Frame: This outcome will be assessed four days prior to the start of the intervention (Day -4) and again 1 day following the final sauna visit (Day 8) ]
  • Change in Maximum Knee-Extension Cycling Power [ Time Frame: This outcome will be assessed four days prior to the start of the intervention (Day -4) and again 1 day following the final sauna visit (Day 8) ]
  • Change in Whole-Body Lean Mass [ Time Frame: This outcome will be assessed four days prior to the start of the intervention (Day -4) and again 1 day following the final sauna visit (Day 8) ]
  • Integrated Skeletal Muscle Protein Synthesis Rate [ Time Frame: Baseline (Day -4) and Day 8 ]

Central Contacts and Locations

Central contacts

Robert D Hyldahl, PhD

8014221237robhyldahl@byu.edu

Jayson R Gifford, PhD

8014223090jaysongifford@byu.edu

Locations

Brigham Young University

Recruiting

Provo, Utah, United States, 84602

Contacts

Robert D Hyldahl, PhD

8014221237robhyldahl@byu.edu

Jayson R Gifford, PhD

8014223090jaysongifford@byu.edu

More Information

Sponsor

Brigham Young University

Last update posted

Sep 29, 2026

Last verified

Sep, 2026

Keywords

  • Heat Therapy
  • Physical Inactivity
  • Sauna
  • Disuse
  • Protein Synthesis
  • Vascular Health

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-30. This information was provided to ClinicalTrials.gov by Brigham Young University on 2026-09-29. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.