The Effects of Dynamic and Static Forest Bathing (Shinrin-yoku) on Physiological and Psychological Health in Males and Females

Abstract

This study aimed to investigate the effects of dynamic and static forest bathing (Shinrin-yoku) on the physiological and psychological health of males and females. Dynamic pre-test and post-test forest bathing was performed on 11 participants (5 males and 6 females) as a single group in a forest environment. In addition, a randomized controlled trial involving 20 participants (10 males and 10 females) was conducted to evaluate static forest bathing in both forest and urban environments. Various physiological indicators, including systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse, heart rate variability (HRV), and self-assessed psychological indicators such as profile of mood states, were measured. Dynamic forest bathing resulted in a significant increase in the natural logarithmic value of the high frequency (lnHF) of HRV and significantly decreased ratio of the natural logarithmic value of the low frequency (lnLF) to lnHF (lnLF/lnHF) of HRV. Static forest bathing not only had the effects of dynamic forest bathing but also significantly decreased the participants’ SBP, DBP, and pulse. Both dynamic and static forest bathing enhanced human parasympathetic nervous system activity and reduced sympathetic nervous system activity, particularly affecting females. Negative mood state scores (tension, anger, fatigue, depression, and confusion) and total mood disturbance scores significantly decreased after forest bathing. In contrast, positive mood state (vigor) scores significantly increased, indicating an enhancement in positive mood. These improvements in mood were particularly pronounced in male individuals. Short-term exposure to a forest environment has positive effects on both physical and mental health of individuals. The extent of these improvements varied according to factors such as engagement in physical activity and gender.