Chronic whole-body heating (i.e., heat therapy) has gained attention as a novel strategy to improve clinical and physiological outcomes in a number of populations. However, whole-body heat therapy is quite uncomfortable and may require trained personnel to ensure participant safety, especially for those more at risk for heat-related illness. Moreover, the applicability and acceptability of whole-body heat therapy are questionable as equipment cost is substantial and adherence will be low if individuals are required to travel if they cannot afford in-home therapy. Home-based leg heat therapy offers an opportunity to leverage the demonstrated benefits of whole-body heat therapy while managing safety and convenience.~The hypothesis will be addressed in the following Specific Aims:~Aim 1: Determine the extent to which home-based leg heat therapy improves functional capacity in older adults. Functional capacity will be assessed before and after heat therapy or sham intervention via the 6-min walk test and the Short Physical Performance Battery.~Aim 2: Determine if home-based leg heat therapy improves vascular function and exercise hyperemia in the older adults of Aim 1. Using state-of-the-art techniques of skeletal muscle microdialysis and high-resolution duplex ultrasound, the investigators will pharmacodissect mechanisms of vascular function and exercise hyperemia before and after each intervention. The outcomes of Aim 2, while providing insight into the mechanisms whereby heat therapy improves functional capacity, should be considered independent of the outcomes of Aim 1 given that vascular health is a key independent, yet modifiable risk factor for cardiovascular morbidity and mortality.
To test the hypothesis that home-based leg heat therapy improves functional capacity, vascular function, and exercise hyperemia in older adults.