Now that the trees are all green where I live, I have found my hikes in the woods feel better. It turns out that there is robust science behind this phenomenon. The first people to recognize and study it were in Japan. It turns out, walking in the woods does far more than make you feel better; it measurably improves many aspects of your health. The Japanese researchers were so impressed with the findings that they coined a term called Shinrin-yoku to represent the joys of immersing ourselves in forests. 

What is Shinrin-yoku?

In the early 1980s, the Japanese Ministry of Agriculture, Forestry, and Fisheries began to encourage citizens to visit the country's numerous forests to improve health and happiness. The term "Shinrin-Yoku," which roughly translated to "taking in the atmosphere of the forest," is now the official Japanese patented term. It is more commonly referred to as forest bathing online. The English term silvotherapy is another word for the same activity. (1)

Whatever the name, we all agree that a nice walk in the woods is therapeutic. The Japanese recognized that those who regularly walked in the woods were happier and healthier. They conducted numerous research projects that proved the benefits are real. 

Just Walk

Science tells us that walking is beneficial, no matter where you do it. Regular walking for exercise has been associated with numerous health benefits, including reduced risk of coronary heart disease and diabetes, weight loss/weight maintenance, and lowered blood pressure. The agreed-upon recommendation is that we walk for thirty minutes a day, five times a week. Even though walking is the most common form of leisure activity, less than 17% of us hit the recommended target. (2) The following video makes it crystal-clear how good walking is and serves as motivation to do it regularly:

Natural Settings Are Better Than Urban Settings, Even While Sitting

Signs and symptoms of excess cortisol include anxiety, sleep disturbances, weight gain (especially in the face and abdomen), fatty deposits between the shoulder blades, diabetes, hypertension, excessive hairiness in women, muscle weakness, osteoporosis, and more. (3) Hunter and colleagues demonstrated ten to thirty minutes of quiet stillness in nature lowers the stress hormone cortisol; from their observations, we can see that lowering high cortisol results in untold benefits. (4) Lowering your cortisol can add years to your life. (5)

Natural Is Better Than Urban 

In 2015, Bratman and others found that walking in a natural environment alleviated the mental stress of urban dwellers more than city walks. (6) Ochiai and research colleagues found that walking in the forest lowered blood pressure. Since high blood pressure is the leading risk factor for heart disease, their finding is significant. (7) The benefits go way beyond what Ochiai found. In 2016, researchers found that forest bathing significantly reduced pulse rate, significantly increased the score for vigor, and decreased depression, fatigue, anxiety, and confusion. (8)

The Nerve

I am sure by now, most of you are familiar with the fight-or-flight response to danger and anxiety. The sympathetic nervous system regulates it. The parasympathetic nervous system is, in a way, the opposite of the sympathetic one. It helps to calm us down. One way to measure the balance between the two is to measure heart rate variability. Believe it or not, our heartbeats are not supposed to be that steady; there should be a slight variation between beats, which can be easily measured. At-home systems are widely available. Kobayashi and others found improvements in HRV in forest bathers. They proved that the calming effect of the forest can be hormonal (cortisol) and neurological (parasympathetic). (9)

A Picture is Worth a Thousand Trees

When I view nature videos while I am on the treadmill due to bad weather, I feel much better than when I watch just about any other type of video. In 2017, Kobayashi and partners found that fifteen minutes of viewing forest scenes improved cortisol levels when compared to viewing urban settings for the same period. (10) Now I know why! So don't fret if you can't get to a forest. Your computer can help, proving not all online time is bad.

Hopefully, this post will remind you to get out into the forest and enjoy the benefits of shinrin-yoku. Sayonara for this week!