title: [Physiological benefits of forest environment: based on field research at 4 sites].
abstract: OBJECTIVE
  To provide scientific evidence of the health benefits of forest therapy in terms of physiological indices.
  
  
  METHODS
  Within-group comparison made by conducting field experiments.
  
  
  METHODS
  Forty-eight young male adults.
  
  
  METHODS
  Field experiments were conducted at four local sites in Japan. At each site, 12 adults participated in a three-day experiment. To compare physiological reactions between two environmental stimuli, experiments were conducted in forest and urban environments. The participants were randomly assigned to visit either the forest or an urban setting and were instructed to view the landscape in a seated position. The physiological reactions of each participant were recorded before, during, and after viewing the stimuli, and the differences in physiological indices were compared between the two groups.
  
  
  RESULTS
  Physiological data revealed that participants demonstrated significantly different reactions in the forest and urban environments. Analysis of heart rate revealed that participants showed a significantly higher ln(HF) and a lower ln(LF/HF) in the forest environment than in the urban environment. Systolic and diastolic blood pressures, pulse rate, and salivary cortisol concentration significantly decreased in the forest environment compared with the urban environment. Subjective evaluation data were generally in accordance with physiological reactions, showing significantly higher scores for "comfortable, natural, soothed, and refreshed feelings" in the forest environment than in the urban environment.
  
  
  CONCLUSIONS
  This study provided very clear scientific evidence of the physiological effects of forest therapy. Our data indicate that forest therapy can decrease stress and facilitate physiological relaxation.
authors: Center for Environment, Health and Field Sciences, Chiba University, Japan.
authors: Juyoung
authors: J
authors: Lee
authors: Bum-Jin
authors: BJ
authors: Park
authors: Yuko
authors: Y
authors: Tsunetsugu
authors: Takahide
authors: T
authors: Kagawa
authors: Yoshifumi
authors: Y
authors: Miyazaki
mesh_terms: D001794:Blood Pressure / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D008297:Male; D011674:Pulse; D012063:Relaxation / Q000502:physiology*; D012463:Saliva / Q000737:chemistry; D014197:Trees; D055815:Young Adult
chemical_list: D006854:Hydrocortisone