Heat Therapy During Reduced Physical Activity
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18+
SponsorBrigham Young University
About this trial
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.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
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
Disqualifiers
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
Trial design
Design model
Parallel
Treatments tested in this trial
Sauna
DeviceParticipants 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
BehavioralParticipants 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.
Treatment groups
60 Participants
are divided into 3 treatment groupsGroup A: Habitual Physical Activity + SaunaExperimental treatment 1 intervention
Group B: Reduced Physical Activity + Room-Temperature Sauna (Control)Sham comparator 1 intervention
Group C: Reduced Physical Activity + Dry SaunaExperimental treatment 2 interventions
Trial outcomes
Primary outcomes
1
Femoral artery endothelial function
Common femoral artery blood flow will be measured using Doppler ultrasound at rest and during passive movement of the lower leg through approximately 90 degrees of motion. The hyperemic response may be expressed as peak blood flow, change from resting blood flow, and/or blood-flow area under the curve. The change from baseline to post-intervention will be compared among groups.
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)2
Change in Maximum Knee-Extension Cycling Power
Maximum exercise power will be determined during a graded knee-extension cycling test in which resistance is progressively increased until the participant can no longer maintain the required cadence. Maximum power will be reported in watts.
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)3
Change in Whole-Body Lean Mass
Whole-body lean mass will be measured using dual-energy X-ray absorptiometry. Lean mass will be reported in kilograms, and the change from baseline to post-intervention will be compared among groups.
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)4
Integrated Skeletal Muscle Protein Synthesis Rate
The integrated fractional synthesis rate of skeletal muscle protein will be determined using deuterium oxide labeling and vastus lateralis muscle biopsies. Deuterium incorporation into newly synthesized muscle protein will be quantified by mass spectrometry and expressed as the fractional synthesis rate over the study period, such as percentage per day. Rates will be compared among the three intervention groups.
Time frame
Baseline (Day -4) and Day 8Secondary outcomes
1
Change in Leg Lean Mass
Regional leg lean mass will be measured using dual-energy X-ray absorptiometry and reported in kilograms. The change from baseline to post-intervention will be compared among groups.
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)2
Change in Mean Interstitial Glucose Concentration
Interstitial glucose concentrations will be monitored using a continuous glucose monitor. Mean glucose concentration will be calculated for the habitual-activity or baseline monitoring period and for the 7-day intervention period and reported in milligrams per deciliter.
Time frame
Days -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 83
Mean Daily Step Count During the Intervention
Daily physical activity will be measured using an accelerometer worn on the wrist, ankle, or waist. Mean steps per day during the 7-day intervention will be used to assess adherence to the habitual-activity or reduced-activity assignment.
Time frame
Days -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 84
Change in Core Temperature During Sauna Exposure
Core temperature will be measured using an esophageal temperature probe during the first and final sauna treatments. The change from pre-sauna temperature to peak temperature during sauna will be reported in degrees Celsius.
Time frame
Day 1 and Day 8Sponsors and contacts
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Source ClinicalTrials.gov