A new study published in the American Journal of Physiology suggests that hot tubs may trigger larger responses in the heart, blood vessels, and immune system compared to saunas, leading to greater health benefits.
The study included 20 healthy adults who participated in three different types of passive heating: a hot tub, a traditional sauna, and a far infrared sauna. Each session was separated by at least one week. Various measures of health were taken before, during, and after each heating session, including core body temperature, cardiac output, and immune cell populations in the blood. Heat therapy in various forms has become popular as a way to improve health and reduce the risk of chronic diseases, and this study sought to determine which form of heat therapy is most effective for boosting health.
The results showed that all three types of heat therapy increased core body temperature and cardiac output. However, of the three, soaking in hot water caused a greater increase than either type of sauna. Additionally, soaking in hot water was the only type of heat therapy that showed a change in immune response. While all three types of heat therapy were somewhat effective for improving health measures, soaking in hot water elicited the greatest responses in the heart and immune system as well as in body temperature.
The authors noted that the three types of heat therapy in this study are commonly used in everyday life, and the conditions of this study mirrored how people might use them in the real world. Of the three types of therapies, soaking in hot water was the most effective at increasing core body temperature, which likely led to it having the greatest impact on the heart and immune system. The authors further noted that people who regularly participate in any type of heat therapy are very likely to see benefits for their health, although hot tubs are likely to be the most effective.
Sources: American Journal of Physiology, Science Daily