Hot water therapy may help manage peripheral arterial disease (PAD)—a common condition affecting blood flow to the arms and legs—just as well as exercise, according to new research. The findings could help people with PAD, who find exercise is difficult. The first-of-its-kind study is published in the American Journal of Physiology—Heart and Circulatory Physiology. The paper was chosen as an APSselect article for June.

PAD is a condition in which fatty buildup accumulates in the arteries, leading to reduced blood flow to the limbs. People with PAD may experience claudication, a type of muscle pain in the legs that occurs while walking. Supervised exercise is the primary non-surgical treatment for PAD, but claudication often limits physical activity. Ongoing heat therapy has been well-established with lowering cardiovascular risk. A team of researchers from New Zealand hypothesized that heat may be more effective than exercise in promoting beneficial cardiovascular changes that, in turn, could increase walking distance in people with PAD.

The researchers studied two small groups of adults with mild-to-moderate claudication. One group was encouraged to attend twice-weekly exercise sessions. During each session, the volunteers walked for up to 30 minutes on an indoor course and performed up to 60 minutes of circuit exercises. The other group participated in spa bathing three to five days a week. The volunteers were encouraged to submerge up to their shoulders in a pool of 102-degree water for 20 to 30 minutes. The research team measured walking ability, blood pressure, heart rate, blood volume, oxygen levels in muscle tissues, peripheral artery blood flow and function and quality of life before and after the sessions.

The researchers found improvements in walking ability and blood pressure among the volunteers. “Contrary to our hypothesis, there was no difference evident between the effects observed in heat therapy via spa bathing and a supervised exercise program,” the research team wrote. “These findings indicate that heat therapy may be a useful alternative form of cardiovascular conditioning for individuals with PAD. Further studies to confirm the clinical benefits of heat therapy will be required along with the refinement of systems to provide heat therapy in a safe and efficient way,” they added.