Onsen – Hot Springs 

Hot springs, or onsen as they are known in Japan, contain a number of dissolved components which are absorbed by the skin on contact, bringing benefits for the body. These components vary according to the peculiarities of the springs. 

Hot springs with therapeutic properties are classified into 10 types according to their specific mineral composition. Guidelines on the most beneficial type of water for a certain health condition are defined by Japan's Ministry of the Environment.

Bathing in hot springs offers three main physical benefits:

- Thermal action: the heat of the waters raises the body temperature, which stimulates circulation, strengthens the immune system, activates metabolism and favors the elimination of toxins from the body.

- Action of hydrostatic pressure: the pressure of hot water acts as a massage on the whole body, improving circulation, as well as relieving tiredness and swelling in the legs.

- Floating action: the weight of the body immersed in water is perceived as lighter, which alleviates the burden on the lower back, legs and joints, and reduces tensions in the body.
 

In addition, hot springs are usually located in regions of lush nature, such as near the sea, mountains, rivers or forests, and contact with these environments can also provide relaxation that is considered effective for mental health and stress reduction. The benefits of the water combined with contact with nature generate what is known in Japan as the “Comprehensive Biological Adjustment Effect of Thermal Waters,” and studies show that spending several days in a thermal water station restores balance to the body, normalizing several health indicators, such as hormone levels and blood pressure.

Source: Japan Ministry of the Environment; ecojin – Volume 74: Sutoresu manejimento kara kangaeru onsen katsuyō-hō (Application methods of thermal waters for stress management) –  only available in Japanese.