What is the primary effect of heat therapy for muscle tension?

The primary effect of heat therapy for muscle tension is that it increases blood flow to the affected area. This increase in blood circulation facilitates the delivery of oxygen and nutrients, which are essential for the healing process. Additionally, improved blood flow helps to remove metabolic waste products that can accumulate due to muscle tension and spasms. As a result, the application of heat can promote relaxation of the muscles, alleviating tension and discomfort.

In contrast, while reducing inflammation may be a desired effect in certain contexts, heat therapy is more typically associated with increasing blood flow rather than directly combating inflammation. It's also important to note that heat therapy does not increase muscle spasms; rather, it is often employed to relieve them. Moreover, the effect on oxygen delivery is not negative; heat therapy actually enhances oxygen delivery rather than decreasing it.