The study suggests that passive heating — exactly what it sounds like, relaxing in a hot bath for an hour — can help reduce inflammation. The idea of passive heating as a medical treatment is relatively new, and popular with one country in particular: Finland. A study in the JAMA Internal Medicine journal from 2015 suggests that spending time in saunas — another act of passive heating — may help ward off cardiovascular diseases.
One thing to note: All of these study participants were men, and given that the male and female bodies can act in drastically different ways, there may be some variety in the results. But even if it doesn’t replace a day’s exercise, soaking in a warm tub can only do good things for your mental health.