Forest bathing research can help us understand a wellbeing practice without turning it into medical treatment. Here we separate short-term study findings, possible explanations and the experience we actually offer in Hakone.
What the research consistently shows
Shinrin-yoku has been studied in Japan since the 1980s, and the physiological findings have been replicated many times. Three results stand out.
Short-term differences in stress markers
The landmark field study measured people in 24 forests across Japan against city environments. Forest settings produced lower cortisol, lower pulse rate, lower blood pressure, greater parasympathetic ("rest and digest") nerve activity and lower sympathetic ("fight or flight") activity.
A later systematic review screened 971 papers, included 22, and meta-analysed 8: salivary cortisol was significantly lower in forest groups than in urban groups.
Park, Tsunetsugu, Kasetani, Kagawa & Miyazaki (2010), Environmental Health and Preventive Medicine; Antonelli et al. (2019), International Journal of Biometeorology
Phytoncides are part of the forest environment
Trees release aromatic compounds known as phytoncides. Their concentration varies with tree species, season and weather, making the air in each forest a distinct sensory environment.
Research continues into how these compounds relate to the wider forest-bathing experience. We describe their presence without treating them as medicine or promising a health outcome.
Some studies report improved mood
Measured on the Profile of Mood States scale, forest sessions have been associated with lower scores for anxiety, depression, anger, fatigue and confusion, and higher scores for vigour.
Li Q. (2022), Environmental Health and Preventive Medicine
Different traditions of time in nature
Japan’s shinrin-yoku practice sits alongside other traditions of spending time outdoors. We find these parallels interesting, but they do not establish that one tradition directly explains the history or effects of another.
Our guiding is rooted in the forests around Hakone, Aki’s training and the needs of the people walking with us. The research references below are a separate source of evidence, not a substitute for that practical care.
The rhythm underneath it
Natural variation, sometimes described using 1/f fluctuation or yuragi, is one proposed way to discuss forest sights and sounds. It is not an established explanation for every benefit associated with forest bathing. Outdoor time, attention, movement, company and expectations may also contribute.
We wrote about this in detail →
See the visual guide to a forest bathing session →
Where we stop
What we will not claim
Forest bathing is not a treatment. The official position, printed on the visitor centre wall at Akasawa where all of this began, is admirably plain: forest bathing and forest therapy do not cure specific diseases. The purpose is to support everyday wellbeing and resilience, not to treat illness. Professor Miyazaki, one of the field's founding researchers, says the same thing — shinrin-yoku is preventive, not a medicinal cure. It is not a substitute for medical care, and we will never suggest otherwise.
Phytoncides are measurable; disease-prevention claims are not established. These aromatic compounds are part of forest air, but their presence does not justify promising that a forest visit will prevent or treat disease.
Expectation plays a part, and the researchers say so. The authors of the largest cortisol meta-analysis noted that anticipated placebo effects may contribute to the results, and called for further research. We think you should know that. It does not make the rest less true — it makes the people reporting it more trustworthy.
So what is actually being offered here?
A few hours in a forest with someone who knows it, moving slowly and making room for sensory attention. The research supports discussing possible short-term relaxation and mood effects; it does not tell us how any particular guest will feel or establish a treatment for illness.
Choose a walk for the time, terrain and experience that suit you. Ground mats and quiet pauses are available, and sitting can replace lying down. If a medical condition affects your participation, ask us about the route before booking and seek medical advice when needed.
What Aki has been reading
If you want to go deeper, these are the books that shaped how we guide.
Shinrin-Yoku: The Art and Science of Forest Bathing
By the man who turned a cultural practice into a scientific discipline — associate professor at Nippon Medical School and president of Japan's Society of Forest Medicine. Part science, part practical guide, part argument for the future of forests.
The insight we use most: the effect does not require a wilderness. It requires attention, and time.
Shinrin-Yoku: The Japanese Art of Forest Bathing
The more restrained of the two founding voices. Miyazaki, of Chiba University, prefers the term "forest therapy" for the scientific work and is careful about what the data can and cannot support.
His insistence that this is preventive rather than curative is the reason we write our science page the way we do.
Your Guide to Forest Bathing
Less about the physiology, more about the craft of guiding: how to offer an invitation, how to hold a silence so that it feels safe rather than awkward, how to close a session properly.
The line that stayed with us: the forest is the therapist. The guide only opens the door.
The papers, if you want the originals
- Park et al. (2010): field experiments in 24 Japanese forests.
- Antonelli, Barbieri & Donelli (2019): systematic review and cortisol meta-analysis. The authors discuss short-term results, limited data and possible expectation effects.
- Li (2022): review of forest-environment research.
This page describes a wellbeing practice and does not constitute medical advice. If you have a health condition, speak to your doctor. Written by Akihiro Wada, certified shinrin-yoku facilitator, Hakone.