Heat therapy (HT) using sauna or hot water immersion can improve cardiovascular and physical function, but these approaches are often impractical for older adults. This pilot randomized, sham-controlled trial evaluated the feasibility of unsupervised, home-based leg HT using water-circulating trousers in sedentary older adults. Twenty-four participants (mean age: 70 ± 3 years; 17 women) were randomized to HT (42°C) or sham (33°C) for 90 minutes daily over 12 weeks. Feasibility outcomes included adherence, retention, and safety. Secondary outcomes included 6-minute walk distance, sit-to-stand time, plantar flexor strength, MRI-derived muscle morphology, quality of life, and blood pressure. Four participants (two per group) withdrew early due to health status changes or scheduling conflicts. Among those who completed the study, adherence was high (HT: 93 ± 11%; sham: 92 ± 35%). Four HT participants reported minor thermal injuries at the knees, which did not hinder adherence or study participation. There were no significant differences between groups for the secondary outcomes. At 12 weeks, the HT group increased their 6-minute walk distance by 37.6 m (95% CI: 14.3 to 60.8), compared to 11.5 m (–12.2 to 35.1) in the sham group (group-by-time interaction, p = 0.092). Plantar flexor strength rose by 4.3 Nm (–2.0 to 10.6) in the HT group and declined by 2.6 Nm (–16.1 to 10.9) in the sham group, with no significant group-by-time interaction (p = 0.31). These findings support the feasibility and acceptability of home-based leg HT in older adults and indicate that protocol and device refinements–particularly to improve usability and safety–are needed before advancing to a larger efficacy trial.
Ro et al. (Fri,) studied this question.