Heat Therapy During Reduced Physical Activity

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.

Detailed Description

Reduced physical activity resulting from illness, injury, hospitalization, or other temporary limitations rapidly impairs cardiovascular, skeletal muscle, and metabolic health. Even short-term reductions in daily physical activity are associated with decreased endothelial function, reduced aerobic capacity, loss of muscle mass, and impaired insulin sensitivity. Previous work from our laboratory has demonstrated that localized heat therapy producing exercise-like increases in muscle temperature attenuates several detrimental adaptations associated with limb immobilization. The present study investigates whether whole-body heat therapy delivered through Finnish dry sauna bathing can similarly reduce the adverse effects of whole-body reductions in physical activity. Healthy adults will be randomly assigned to one of three intervention groups: * Habitual physical activity with daily Finnish dry sauna therapy * Reduced physical activity (\~1,000 steps/day) with daily room-temperature sauna visits * Reduced physical activity (\~1,000 steps/day) with daily Finnish dry sauna therapy The intervention will last seven days. Cardiovascular function, exercise tolerance, muscle protein synthesis, body composition, glucose regulation, blood pressure, and additional physiological variables will be assessed before and after the intervention. The findings will determine whether passive heat therapy is an effective strategy for preserving cardiometabolic health during temporary reductions in physical activity.

Eligibility Criteria

Interventions