Physiological effects of Shinrin-yoku (taking in the atmosphere of the forest) in a mixed forest in Shinano Town, Japan

The purpose of this study was to examine the physiological effects of Shinrin-yoku (taking in the atmosphere of the forest). The subjects were 12 male university students. On the first day of the experiments, six subjects went to the forest area, and the other six went to a city area as a control. On the second day, subjects went to the opposite areas as a cross-check. In the afternoon, they were seated on chairs watching the landscapes of their given area for 15 min. Heart rate variability (HRV), salivary cortisol and pulse rate were measured as physiological indices in the morning and in the evening at the place of accommodation, before and after watching the landscapes in the field areas. The high-frequency power of HRV of subjects in the forest area was significantly higher than that of subjects in the city area. The pulse rate of subjects in the forest area was significantly lower than that of subjects in the city area. The salivary cortisol concentration of the subjects in the forest area was significantly lower than that of subjects in the city area. The results of physiological measurements show that Shinrin-yoku was an effective form of relaxation.