Home-based Leg Heat Therapy to Improve Walking Performance in Elderly Individuals: a Pilot Trial

Aging and a sedentary lifestyle are associated with a progressive deterioration of skeletal muscle contractile function and cardiorespiratory fitness, resulting in an impaired capacity to perform daily activities and maintain independent functioning. Few therapeutic options exist to combat the skeletal muscle abnormalities and restore muscle strength in older individuals. Heat therapy (HT) is a practical, non-invasive therapeutic tool that has been shown to elicit beneficial adaptations in both vasculature and skeletal muscle. This pilot randomized, sham-controlled trial aimed to establish the feasibility and safety of home-based leg HT in community-dwelling older adults and inform the design of a future, larger study. Participants were randomized to either an HT or a sham group and were asked to apply the treatment daily for 90 min over 12 consecutive weeks. The primary outcomes were compliance with the HT regimen, measured by a hidden timer, completion rates, and device safety. The secondary goals were to examine the effects of leg HT on 6-min walk distance, sit-to-stand performance, blood pressure, quality of life, and the morphology and strength of the calf muscles, as assessed using combined T1-weighted and mDixon magnetic resonance imaging (MRI). Building upon previous findings in young individuals, preclinical models of PAD, and older individuals with PAD, we hypothesized that older adults treated with leg HT for 12 weeks would display improved walking performance, increased calf strength, and reduced intramuscular fat when compared to sham-treated individuals.