In China, FHW is based on high-quality forest resources and good forest environment. Guided by health theory and supported by the combination of traditional medicine and modern medicine, FHW has developed forest medical treatment, convalescence, rehabilitation, health care and health preservation, while also taking into account leisure, recreation, and vacation, etc. As such, FHW has the main functions of nourishing body, mind, temperament, wisdom, and morality, all of which are beneficial to human physical and mental health (1). It is similar in effect to forest therapist in Japan. Forest therapist stems from forest bathing, a short leisurely visit to a forest for the purpose of relaxation, called “Shinrin-yoku” in Japan (2).

As human society becomes increasingly urbanized, modern societies are subject to high levels of stress owing to the fast pace of life. People living in urban areas are prone to irritability and tiredness due to being in a crowded, unpleasant environment that is characterized by noisy traffic and unpleasant smells su6ch as automobile exhausts (3). Psychologically, stress refers to mental restraint and tension. The source of stress is external stimuli, such as tasks and challenges. Appropriate stress can be beneficial, for instance it can improve the efficiency of work and learning. However excessive stress can cause physical and mental suffering and even affect physical health.

According to the China National Bureau of Statistics, 35–60 years old is middle-aged. Middle-aged people are the predominant support of social labor force, family, and social responsibility which means middle-aged people tend to report more stress than any other age group (4). Various physiological and psychological diseases are caused by stress, thus stress greatly affects humans’ health and well-being (5, 6). Forest bathing or forest therapy refers to immersing oneself in nature and experiencing a forest’s atmosphere in order to improve mental and physical health (7–11). This therapeutic experience engages all five senses, with activities such as walking or simply being in the forest, which can effectively alleviate stress and confer numerous health benefits (12). As a preventive and alternative treatment approach, forest therapy has gained prominence as a means to manage stress and promote overall health and well-being, stemming from the restorative effects of spending time in a green, healthy environment (13).

Wencheng County is located in the mountainous area of southern Zhejiang Province, China (119°46′–120°15′E, 27°34′–57°59’N). Wencheng County boundary belongs to subtropical marine monsoon climate area, the forest coverage rate is 71.5%, its annual average temperature is 14–18.5°C, and it has a perennial frost-free period of 285 days. The diet and accommodation within the FHW experience study were arranged in Yueman FHW base in Wencheng County, which is a demonstration FHW base in Wenzhou City. This study will investigate the effects of FHW experience on the decompression and mood regulation in a middle-aged sample through monitoring the dynamic changes of exercise parameters, routine physiological indicators, and stress of the participants. Evaluating the potential psychological and physiological benefits of the short FHW program could help to further develop this type of program, provide proof of its effectiveness, and encourage the public to enter the forest, thus promoting the development of FHW industry and improving national health.

It has been reported that a higher ambient temperature reduces blood pressure, whereas a lower ambient temperature raises blood pressure (20–23). Several studies have determined that participants walking in a forest environment have lower pulse rates and diastolic and systolic blood pressures than in urban settings (17, 24–31). However there was no significant difference in blood pressure between the forest and urban area walking groups because of the big difference in ambient temperature between the forest (lower temperature) and urban (higher temperature) environments (2). Forest bathing significantly reduces blood pressure by reducing sympathetic nerve activity and urinary adrenaline, noradrenaline, and dopamine levels (2). In this study, the diastolic and systolic blood pressures of the participants showed a trend of first rising and then decreasing. The initial elevation of blood pressure may have been caused by the lower forest temperature and then the forest environment caused the later decrease.

The POMS test is a well-accepted quantitative means of evaluating mood, widely used in psychological investigations (3). The POMS measurements in the current study confirm previous findings that forest environments can relieve human psychological tension, depression, anger, fatigue, and confusion (27), suggesting that the subjects were physiologically relaxed during the forest bathing trips (17, 27, 30, 32–40). Some studies have also reported that forest environments can lead to improvements in other psychological responses, including anxiety and depression (29, 41–45). Kasetani et al. reported that a relationship exists between the POMS score and the physical environmental factors, such as relative illumination, relative humidity, atmospheric pressure, etc. (46). Studies have found that individuals with high blood pressure or high stress levels are more likely to exhibit improvement after forest bathing than healthy individuals (32, 44). It is important that the improvement in POMS score for those with depressive tendencies was much greater than for the non-depressive tendencies after forest bathing (47). Improvements observed in depressive symptoms and psychosocial functions may be linked to the possible activation of neural networks through positive emotional reflection (48), and improved social cognitive functions through the stimulation of mirror neurons, leading to a better understanding of the intended actions and emotions of others (49).

Previous studies have shown that compared with exposure to urban settings, exposure to forest environments results in higher parasympathetic and lower sympathetic nervous activity (10, 17, 27, 43). Both epinephrine levels and cortisol levels have been shown to decrease after a forest bathing trip suggesting forest bathing trip could reduce the stress level of Chronic Obstructive Pulmonary Disease (COPD) patients (50). From the viewpoint of attention restorative theory (51), these results strongly support that the forest is a good restorative environment for human beings (27). These studies have provided some evidence that living in a forest environment, even for a short time, exerts benefits on human health (3). Evaluating the effects of the short forest bathing program on psychological and physiological benefits could help to develop this type of program, provide proof of its effectiveness, and encourage the public to connect with nature (19). In addition, forest bathing may represent a potential medical intervention in several pathologies, including inflammation and cardiovascular and nervous conditions (3).

After the forest recuperation experience, both males and females demonstrated significantly reduced negative emotions, significantly increased positive emotions, and a decreased stress value on the second day of the experience. Both subjective and objective physiological evaluation indicators showed that the forest recuperation experience activities relieved stress. FHW did have a relaxing effect, promoting health, and alleviating fatigue and sleepiness of females more so than males. What factors improve mood state? Quiet atmosphere, beautiful scenery, mild climate, fresh air, and other forest environments can increase parasympathetic activity and reduce sympathetic activity (27). Because of the particularity of environments and individual differences, the effect of forest environment health care and recuperation varies from person to person (52). The forest walk and other activities during the FHW experience may also have a beneficial impact on the emotional state. The improvement of the participants’ emotions is the result of the above factors and other comprehensive factors. Due to the short duration of this study and the small number of participants, the exact conclusion of the positive effects of FHW requires further research, which should involve a larger cohort of participants and extend the period of exposure to FHW. Recognizing FHW as a multidisciplinary field, involves multiple fields such as forestry, medicine, psychology, management, and education, and requires interdisciplinary cooperation and participation (13).

The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.

The studies involving humans were approved by the ethics committee of Dian Diagnostic. The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study.

WQ: Writing – original draft, Writing – review & editing, Data curation, Investigation, Methodology, Project administration. SY: Writing – review & editing, Data curation, Investigation. QH: Conceptualization, Investigation, Resources, Writing – review & editing, Software. MY: Funding acquisition, Writing – review & editing, Project administration.