Forest Bathing for Stress and Burnout: Nature Contact as a Nervous System Reset
Time among trees may measurably lower stress hormones. What that means for you when you are only functioning, and how much forest per week the studies point to.
We almost always treat exhaustion as a time problem. As if the body had simply been given too few hours. Most of the time, though, it is not a time problem but a signal problem. For months, the nervous system has stopped receiving any cue that there is no danger right now.
I bet you know the feeling. You did nothing all weekend. You were in bed by ten. And on Monday you are still empty.
This is the point where many people start doubting themselves. They think they are weak or ungrateful. What they are actually experiencing is something very concrete: their body has forgotten how recovery works. Not as a metaphor. As a physiological state.
And this is exactly where a topic becomes interesting that ended up in the wellness corner although it really belongs in physiology. Forest bathing.
What awaits you in this article
- Why your stress system no longer switches off
- What measurably happens in the forest
- The four clinical PNI lenses on nature contact
- Cortisol, amygdala, rumination, immune cells
- Where the evidence honestly gets thin
- The 120-minute mark per week
- Three levers you can start tomorrow
- When the forest is not enough
When the alarm never fully switches off
Imagine an alarm system that went off once and was never fully disarmed afterwards. It no longer screams. But it hums. Constantly. Quietly enough that you get used to it.
That describes chronic sympathetic activation rather well. Your autonomic nervous system has two large branches. The sympathetic branch is the accelerator, responsible for acting, fighting, delivering. The parasympathetic branch is the brake-and-digest side, responsible for repair, digestion, deep sleep and immune work.
Being healthy does not mean having little sympathetic activity. Being healthy means being able to switch quickly between the two. This ability to switch is called flexibility, and it is the first thing lost under sustained strain.
Perception
Your brain rates a situation as a demand. This happens faster than you can think, among other places in the amygdala, a core structure for threat appraisal.
Hypothalamus
It releases CRH, the start signal of the stress axis. In parallel, a direct nerve impulse travels to the adrenal medulla, where adrenaline and noradrenaline are produced within seconds.
Pituitary gland
It releases ACTH into the blood. This is the slower, hormonal route that takes minutes instead of seconds.
Adrenal cortex
Cortisol is released. It mobilizes sugar, dampens inflammation in the short term and sharpens attention. In the short term this is brilliant.
Feedback
Cortisol is meant to turn the axis back down via receptors in the hippocampus. Under sustained strain this feedback can become sluggish. Then the engine keeps running even though nobody is pressing the accelerator any more.
This is the point where stress turns into something else. The exhaustion does not come from having done too much. It comes from your system no longer getting into repair mode in between.
You are not tired because you slept too little. You are tired because your body no longer reaches the depth of sleep in which repair takes place.
Recovery is not a state of doing nothing. Recovery is an active performance of your nervous system. And like every performance, it needs a trigger. So the question is not whether you had enough of a break. The question is whether your body received any signal during that break to switch over at all.
And now you know why doing nothing on its own often changes nothing. A dark room with a phone in your hand sends the nervous system not a single safety signal.
The man who could no longer switch off at the weekend
I know this pattern very well. A man in his early forties, a leadership role, a lot of responsibility, no dramatic crisis. He did not come because he had collapsed. He came because he noticed that nothing gave him joy any more.
What struck me during the history taking: he did not have a single hour in the week without a screen, without a conversation and without a task. His sleep was formally fine, seven hours, but he woke up between three and four in the morning. Holidays no longer helped, because he stayed reachable there too.
The turning point was unspectacular. He started walking in the forest three times a week. No headphones. No goal. No step counter. At the beginning he found it boring and was honestly annoyed. After about three weeks he reported that he had slept through the night for the first time in months.
In parallel we worked on other things, on his sleep rhythm, on being reachable, on nutrient supply. It was never the forest alone.
What measurably happens in the forest
Forest bathing sounds esoteric. Its origin, though, is surprisingly sober. The term Shinrin-yoku was coined in 1982 by the Japanese Ministry of Agriculture, Forestry and Fisheries, and since 2004 a systematic line of research has been running in Japan. This is not about hugging trees. It is about a defined stay in a forest environment, usually walking slowly and afterwards sitting and looking.
Cortisol: the small but repeatable effect
An Italian group around Antonelli systematically searched the literature on forest bathing and cortisol in 2019. Of 971 screened articles, 22 made it into the review and eight into the actual meta-analysis.
In almost all included studies, cortisol was lower in the forest groups than in the city groups. The pooled mean difference in salivary cortisol after the intervention was 0.05 micrograms per deciliter, with a confidence interval of 0.04 to 0.06.
What this means for you: the effect is real and reproducible, but it is small and short-lived. The authors themselves write that expectation-driven placebo effects could play an important role. I find that honest and important.
Antonelli M, Barbieri G, Donelli D. Int J Biometeorol. 2019. DOI: 10.1007/s00484-019-01717-xKobayashi and colleagues sent 74 young men into a forest and into an urban setting for 15 minutes each and measured salivary cortisol before and after.
In the forest the mean dropped from 9.70 to 8.37 nanomoles per liter. In the city it barely changed, from 10.28 to 10.01. The statistical interaction between environment and walking was clear. Just under 69 percent of the participants responded with a drop at all.
What this means for you: not everyone responds the same way. About a third showed no drop. That fits my clinical observation that people respond very differently to environmental cues.
Kobayashi H, Song C, Ikei H et al. Front Public Health. 2019. DOI: 10.3389/fpubh.2019.00376The autonomic nervous system: more brake, less accelerator
Park and colleagues ran the same experimental design in 24 Japanese forests. Twelve people each walked for about 16 minutes and then spent about 14 minutes looking at a forest or a city landscape, with the groups swapped the following day.
Salivary cortisol, blood pressure, pulse and heart rate variability were measured. In the forest there was lower cortisol, a lower pulse, lower blood pressure, higher parasympathetic and lower sympathetic activity than in the city.
What this means for you: this is perhaps the most important observation in the whole field. It is not the hormones alone that change, it is the balance of the autonomic nervous system. Exactly the quantity that is lost under chronic overactivation.
Park BJ, Tsunetsugu Y, Kasetani T, Kagawa T, Miyazaki Y. Environ Health Prev Med. 2010. DOI: 10.1007/s12199-009-0086-9Ideno and colleagues pooled 20 investigations with a total of 732 participants on forest environments and blood pressure.
Both systolic and diastolic blood pressure were significantly lower in the forest environment than in the comparison environment.
What this means for you: this is not blood pressure therapy. But it shows that the relaxation response reaches into circulatory regulation and is not merely a feeling.
Ideno Y, Hayashi K, Abe Y et al. BMC Complement Altern Med. 2017. DOI: 10.1186/s12906-017-1912-zThe brain: amygdala and the rumination loop
Now it gets particularly relevant for people close to burnout. Because what keeps you awake at night is rarely the task list. It is circling around it.
A group at the Max Planck Institute for Human Development in Berlin had 63 healthy people walk either for one hour through the forest or for one hour along a busy shopping street. Brain activity during a social stress task was measured before and after the walk.
After the forest walk, amygdala activity fell. After the city walk it remained unchanged.
What this means for you: the amygdala is the structure that decides whether a situation counts as a threat. If one hour in the forest can dampen its reactivity, then nature contact is not a wellness detail but an intervention at the appraisal level of your stress system.
Sudimac S, Sale V, Kühn S. Mol Psychiatry. 2022. DOI: 10.1038/s41380-022-01720-6The same group looked at the data separately by sex. The decrease in amygdala activity appeared in the women, not in the men.
In addition, arithmetic task performance improved in women after the nature walk, whereas in men it improved after the city walk.
What this means for you: this is a secondary analysis in a small sample and should not be over-interpreted. But it is a good hint that nature contact does not land the same way with everyone. If it does not work for you, that is not necessarily about you.
Sudimac S, Kühn S. Front Psychol. 2022. DOI: 10.3389/fpsyg.2022.931905Bratman and colleagues at Stanford University had healthy participants walk for 90 minutes in a natural or in an urban environment.
After the nature walk, both self-reported rumination and activity in the subgenual prefrontal cortex went down. After the city walk, neither of these changes appeared.
What this means for you: the subgenual prefrontal cortex has been linked in other work with self-focused withdrawal and rumination. So it may be that nature does not simply calm you but interrupts the thought loop itself.
Bratman GN, Hamilton JP, Hahn KS, Daily GC, Gross JJ. Proc Natl Acad Sci USA. 2015. DOI: 10.1073/pnas.1510459112It is not about emptying your head. It is about your head finally getting something else to work on than you.
Berman, Jonides and Kaplan tested what is known as attention restoration theory. They compared walks in nature with walks in the city, and additionally the mere viewing of nature images.
In both experiments, directed attention improved after nature contact, measured with a backwards digit span and an attention task.
What this means for you: the explanation behind it is elegant. Nature draws attention gently and from the bottom up, without you having to steer actively. A street, by contrast, constantly demands directed attention, if only so that no car catches you. The forest gives your control instance a break.
Berman MG, Jonides J, Kaplan S. Psychol Sci. 2008. DOI: 10.1111/j.1467-9280.2008.02225.xAnd now you know why a forest walk can work differently from a walk around the block. Not because of trees as a symbol. Because of the kind of attention the environment asks of you.
Four lenses on the same walk
In clinical psychoneuroimmunology we never look at only one system. A person close to burnout rarely has an isolated nerve problem. They have a pattern that runs through four levels. Here is the same forest walk, seen through four lenses.
Nervous system
Low stimulation combined with a rich sensory world may raise parasympathetic and lower sympathetic activity. At the cellular level, higher vagal tone means more acetylcholine at the target organs, a slower heart rate and better digestive blood flow. Exactly the conditions under which repair can take place at all.
Hormonal system
Falling cortisol is only the tip. What matters is the feedback: if the axis is regularly allowed to power down, glucocorticoid receptors may stay more sensitive. A sluggish feedback loop is exactly what is discussed under sustained strain. At the same time, a permanently running stress axis competes with the production of sex hormones.
Immune system
The vagus can act in an inflammation-dampening way via the cholinergic reflex arc. In addition, Japanese work describes an increase in natural killer cells after multi-day forest stays. Volatile plant compounds and the decline in stress hormones are discussed as reasons. The studies are small, and that has to be said.
Metabolism
Cortisol mobilizes glucose. If it runs permanently, that can burden insulin sensitivity. On top of that comes a banal but powerful factor: whoever is outdoors gets daylight on the retina and thereby stabilizes the internal clock. And the internal clock helps steer when cortisol should rise in the morning and fall in the evening.
The group around Li accompanied twelve men between 35 and 56 years of age on a three-day forest trip and on a comparably active city trip.
After the forest trip, natural killer cell activity and the number of these cells rose, and adrenaline in the urine fell. The effect was still measurable more than seven days later. After the city trip, none of this appeared. Alpha-pinene and beta-pinene were detected in the forest air and practically not in the city air.
What this means for you: what is interesting here is less the cancer prevention often made of it, and more the duration. When an effect outlasts a week, we are no longer just talking about a change in mood.
Li Q, Morimoto K, Kobayashi M et al. Int J Immunopathol Pharmacol. 2008. DOI: 10.1177/039463200802100113Many people believe they have to calm their nervous system down. That sounds logical but often leads straight into the next effort. Meditation as an achievement. Breathing exercises as a task.
You do not calm your nervous system. You give it an environment in which it powers down by itself. That is a completely different approach. You are not doing anything right. You are simply going somewhere else.
Where the evidence gets thin
Now the part that wellness texts leave out. I consider it the most important one.
Many of the classic Japanese papers have twelve participants, mostly male, mostly young and healthy. For questions about mechanism that is entirely legitimate. For the question of what a 48-year-old exhausted person gains from it, it is an extrapolation, not an answer.
You notice whether you are standing in a forest or on a main road. That cannot be blinded. The meta-analysis on cortisol explicitly names expectation-driven placebo effects as a relevant factor. That does not devalue the effect, because expectation is a genuine physiological mechanism. But it changes what we are allowed to claim.
A meta-analysis of 36 papers with 3,554 participants found a significant reduction in depression and anxiety symptoms. For physical measurements such as blood pressure and heart rate, the results were considerably less consistent. Anyone selling forest bathing as a cardiovascular measure is going beyond the data.
A systematic review examined 38 biomarkers across 31 burnout studies. The result: not a single robust marker. The meta-analyses on the cortisol awakening response, on blood cortisol and on blood pressure showed no differences between those affected and healthy people. So if someone offers to measure your burnout with a saliva test and then treat it, be skeptical.
A systematic review of 28 papers from the years 2015 to 2019 formally assessed methodological quality. Randomized studies scored significantly better than non-randomized ones. A large part of the field, however, still consists of non-randomized investigations.
An umbrella review of 16 systematic reviews reaches this conclusion: the best available evidence supports forest bathing as a complementary practice for promoting mental and physical wellbeing. For use as a therapy in organic disease it is not yet sufficient.
That is exactly how I would put it too. The forest is not a medicine. It is an environment in which your body is allowed something it is otherwise no longer allowed.
How much forest, how often
The most frequent question in consultation is not whether, but how much. There is a surprisingly usable number for that.
White and colleagues analysed a nationally representative British survey of 19,806 people. Participants were asked about their nature contact in the previous seven days, evaluated in blocks of 60 minutes.
From 120 minutes per week onwards, the likelihood of reporting good health rose markedly. For the range of 120 to 179 minutes the odds ratio was 1.59 with a confidence interval of 1.31 to 1.92, and for high wellbeing 1.23 with an interval of 1.08 to 1.40. The association reached a plateau between 200 and 300 minutes. And it made no difference whether the time came in one block or in several short visits.
What this means for you: this is a cross-sectional survey, so it says nothing about causation. But as an orientation it is worth its weight in gold, because it takes the drama out of the target. Two hours per week. Spread out however suits you.
White MP, Alcock I, Grellier J et al. Sci Rep. 2019. DOI: 10.1038/s41598-019-44097-3Li and Kawada summarized several of their own investigations. In this work, the raised activity of natural killer cells after forest visits was still detectable in some participants more than 30 days later.
From this the authors derived the consideration that a forest visit roughly once a month might be enough to hold that level. In a separate paper, a single day trip with two sessions of two hours of walking was already enough to raise NK activity and lower cortisol in the blood as well as adrenaline in the urine.
What this means for you: short units for the nervous system, longer units for the immune markers. Both are small studies. But the direction is consistent.
Li Q, Kawada T. Int J Immunopathol Pharmacol. 2011;24(1 Suppl):39S-44S. PubMed ID: 21329564Three levers you can start tomorrow
No programme. No app. Three things that together add up to about two hours per week.
Twenty minutes, three times a week, without headphones
Slowly. Without a goal. Without counting steps. The phone stays in your pocket, not in your hand. This point is not decoration: attention restoration only works if your directed attention is actually allowed to pause. A podcast prevents exactly that.
If it feels boring at the beginning, that is a good sign. Boredom is often the first moment in which the system downshifts.
One longer session per week, ideally in the morning
One to two hours in real woodland. The morning has a double advantage, because you also get bright daylight on the retina. That is the strongest time cue for your internal clock and therefore also for your cortisol curve.
Berlin makes this easy. Grunewald, Tegeler Forst, Wuhlheide and Düppeler Forst can all be reached by public transport.
One sensory anchor per walk
Stop once for two minutes and deliberately direct your attention to a single sensory channel. Only hearing. Or only smelling. Or only the temperature on your skin.
This is not a spiritual add-on, it is the practical core of what the studies measured as the viewing phase. In the Japanese field experiments, this seated viewing phase was a measurement point of its own, and it showed its own effects.
Self-check: am I in chronic overactivation?
- I wake up between three and four in the morning, often with a thought in my head.
- I need caffeine to get started at all, and alcohol or a screen to stop.
- A free day feels more restless than restful.
- I have become more irritable without anything having objectively changed.
- Minor infections last longer than they used to.
- I feel less joy in things that used to give me joy.
- My digestive rhythm has changed for no discernible reason.
If you nod at four or more points, that is not a diagnostic tool. It is a hint to take the topic seriously and have it medically assessed, instead of overwriting it with more discipline.
This is not about functioning better in the morning. You can already function. That is precisely the problem.
It is about being able to feel something again that is not a task. The smell of rain. The sense that an hour has passed without you having used it. These moments are not a luxury. They are the evidence that your nervous system can still switch over.
When the forest is not enough
I want to be very clear here, because this topic is quickly trivialized.
Classical medical and psychotherapeutic treatment of exhaustion states and depression is important and in many cases the decisive step. What an integrative view can offer in addition is the question of the environment your nervous system stands in all day long. That is not an opposition. It is an addition.
And there is a second limit that is mentioned less often. If your work situation structurally overwhelms you, no forest walk will offset that. Two hours of nature per week against 60 hours of constant pressure is not a calculation that adds up. Nature contact may support your capacity to recover. It cannot replace a cause.
And now you know why I consider forest bathing neither esoteric nor a therapy. It is one of the few measures that costs nothing, has hardly any side effects and points in the same direction across several independent investigations. That is not little. And it is also not everything.
Frequently asked questions
What exactly is forest bathing?
Forest bathing means spending time in a forest slowly and without a goal, taking in the atmosphere deliberately through your senses. The Japanese term Shinrin-yoku was coined in 1982 by the Japanese Ministry of Agriculture, Forestry and Fisheries.
It is not a sport and not a hike. The studies mostly work with very short units of 15 to 20 minutes of walking plus a phase of simply looking. In the Japanese field experiments, salivary cortisol, pulse, blood pressure and heart rate variability were measured.
So the core is not performance, it is low stimulation combined with a rich sensory environment.
Can forest bathing really lower the stress hormone cortisol?
The data suggest it can, but the effect is small and short-lived.
A systematic review with meta-analysis by Antonelli and colleagues from 2019 evaluated 22 studies, eight of them quantitatively. Salivary cortisol in the forest groups was significantly lower after the intervention than in the city groups, with a mean difference of 0.05 micrograms per deciliter.
The authors themselves stress that expectation-driven placebo effects may play an important role. A Japanese field study with 74 men showed a drop in salivary cortisol after a 15-minute forest walk from 9.70 to 8.37 nanomoles per liter, while the city walk barely changed the values.
How long do I have to stay in the forest for it to do anything?
For the acute relaxation response, 15 to 20 minutes were enough in the experiments.
For the link with general health and wellbeing there is a better reference point: in a British cross-sectional survey of 19,806 people, the likelihood of reporting good health rose markedly from around 120 minutes of nature contact per week. The association reached a plateau between 200 and 300 minutes per week.
Notably, it made no difference whether the 120 minutes came as one long visit or as several short ones. This is an observational study, it does not prove causation, but it gives a usable target.
Can forest bathing help with burnout?
There is no robust study that has tested forest bathing as a burnout therapy. What does exist is data on stress markers, on anxiety and depression symptoms, and on brain activity in stress-processing regions.
A meta-analysis of 36 papers with 3,554 participants found a significant reduction in depression and anxiety symptoms, while the physical measurements were less clear-cut.
When exhaustion is looming, regular nature contact can therefore be a sensible building block that may support your capacity to recover. It does not replace medical assessment, psychotherapy or a change in working conditions.
Is a city park enough, or does it have to be a real forest?
A park is clearly better than no green at all.
The Berlin study at the Max Planck Institute for Human Development compared one hour of walking in the Grunewald forest with one hour on a busy shopping street and found lower amygdala activity after the forest walk. The British population survey explicitly counted every form of nature contact, parks included.
What may set a forest apart from a small city park is the concentration of volatile plant compounds in the air and the lower noise level. For everyday life the rule is simple: the park you can reach beats the ideal forest you never drive to.
What are phytoncides and what is actually established about them?
Phytoncides are volatile organic compounds released by trees, among them alpha-pinene and beta-pinene. In the measurements by the Japanese group around Li they were detectable in forest air and practically absent in city air.
In the same investigations, natural killer cell activity rose after a multi-day forest trip, and the effect was still measurable seven days later. These are small studies, mostly with twelve participants and without a blinded control.
The connection is biologically plausible and is being discussed, but it is not established with the certainty of a large randomized trial.
Is forest bathing a substitute for psychotherapy or medication?
No. An umbrella review of 16 systematic reviews concluded that the available evidence supports forest bathing as a complementary practice for promoting mental and physical wellbeing, but that it is not yet sufficient for use as a therapy in organic disease.
If you have been unable to get going in the morning for weeks, if joy and drive are missing, or if thoughts of death occupy you, that belongs in medical hands.
The forest can be part of a plan. It is not the plan.
How often per week should I go into the forest?
A sensible orientation from the available data: around 120 minutes of nature contact per week in total, spread across several short units or bundled into one day.
For the immune markers from the Japanese work, it has additionally been discussed that a longer forest stay once a month might hold the raised level of natural killer cell activity. Both figures come from small or observational studies.
More important than the perfect number is regularity, because an overactive stress system does not change over a single afternoon.
What is the difference between jogging in the forest and forest bathing?
Jogging is training, forest bathing is regulation. During running the sympathetic branch rises first, which is useful and healthy when the load is well managed. During slow walking without a goal the parasympathetic response predominates instead.
In the Japanese field experiments across 24 forests with a total of 280 participants, the forest showed higher parasympathetic and lower sympathetic activity than the city.
People who are already exhausted usually benefit from the slow format first. Training comes afterwards.
I live in the middle of Berlin. What can I actually do?
Take the nearest green space and make it a habit rather than a project. Twenty minutes of slow walking without headphones and without a phone in your hand, ideally in the morning, because that also gives you daylight for your internal clock.
If you can manage it, put one longer session per week into real woodland. With Grunewald, Tegeler Forst, Wuhlheide and Düppeler Forst, Berlin offers several reachable options.
The decisive point is not the scenery, it is that you are not getting anything done while you are there.
Are there people for whom forest bathing is not suitable?
Caution makes sense with pronounced pollen allergy during the relevant season, with tick exposure without suitable clothing and checks, and with severe physical limitation where even slow walking is a strain.
People with acute anxiety symptoms sometimes find large, silent spaces unpleasant at first. A small, manageable park is then the better entry point.
And anyone going through an acute mental health crisis should seek professional help first and not head into the forest alone.
More from the Natural Forces guide
All topics in this cluster
- Using natural forces in everyday life: the overview
- Forest bathing: what happens in the body
- Morning light and the internal clock
- Blue light and circadian rhythm
- How much sun does the body need
- Vitamin D deficiency in winter
- Cold, the immune system and hormesis
- Ice bathing for beginners
- Sauna and the heart: how often
- Breathing techniques and the vagus nerve
- Zone 2 training and fat metabolism
- Movement as medicine at the cellular level
- Putting sleep hygiene into practice
- Lifestyle as therapy
If the topic of exhaustion keeps occupying you
Burnout and the stress system
What happens in the body when exhaustion becomes chronic
Breathing techniques and the vagus nerve
The second route into the parasympathetic branch
Morning light and the internal clock
Why the cortisol curve depends on light
Sleep hygiene
How repair during sleep can happen at all
Sources
All statements were checked against the original abstracts in PubMed. Figures are taken from the abstracts and were not converted independently. Part of the evidence on forest bathing comes from small, non-blinded field studies. The reported associations are biologically plausible and have repeatedly been observed pointing in the same direction, but they are not established with the certainty of large randomized therapy trials.
- Antonelli M, Barbieri G, Donelli D. Effects of forest bathing (shinrin-yoku) on levels of cortisol as a stress biomarker: a systematic review and meta-analysis. Int J Biometeorol. 2019;63(8):1117-1134. DOI: 10.1007/s00484-019-01717-x [Meta-analysis, k=8 of 22 studies]
- Park BJ, Tsunetsugu Y, Kasetani T, Kagawa T, Miyazaki Y. The physiological effects of Shinrin-yoku: evidence from field experiments in 24 forests across Japan. Environ Health Prev Med. 2010;15(1):18-26. DOI: 10.1007/s12199-009-0086-9 [Real-world, crossover field experiment, n=280]
- Park BJ, Tsunetsugu Y, Kasetani T et al. Physiological effects of Shinrin-yoku, using salivary cortisol and cerebral activity as indicators. J Physiol Anthropol. 2007;26(2):123-128. DOI: 10.2114/jpa2.26.123 [RCT, crossover, n=12]
- Kobayashi H, Song C, Ikei H, Park BJ, Kagawa T, Miyazaki Y. Combined effect of walking and forest environment on salivary cortisol concentration. Front Public Health. 2019;7:376. DOI: 10.3389/fpubh.2019.00376 [Real-world, field experiment, n=74]
- Ideno Y, Hayashi K, Abe Y, Ueda K, Iso H, Noda M, Lee JS, Suzuki S. Blood pressure-lowering effect of Shinrin-yoku (forest bathing): a systematic review and meta-analysis. BMC Complement Altern Med. 2017;17(1):409. DOI: 10.1186/s12906-017-1912-z [Meta-analysis, k=20 studies, n=732]
- Sudimac S, Sale V, Kühn S. How nature nurtures: amygdala activity decreases as the result of a one-hour walk in nature. Mol Psychiatry. 2022;27(11):4446-4452. DOI: 10.1038/s41380-022-01720-6 [RCT, intervention study with fMRI, n=63]
- Sudimac S, Kühn S. A one-hour walk in nature reduces amygdala activity in women, but not in men. Front Psychol. 2022;13:931905. DOI: 10.3389/fpsyg.2022.931905 [RCT, secondary analysis by sex, n=63]
- Bratman GN, Hamilton JP, Hahn KS, Daily GC, Gross JJ. Nature experience reduces rumination and subgenual prefrontal cortex activation. Proc Natl Acad Sci USA. 2015;112(28):8567-8572. DOI: 10.1073/pnas.1510459112 [RCT, intervention study with fMRI]
- Berman MG, Jonides J, Kaplan S. The cognitive benefits of interacting with nature. Psychol Sci. 2008;19(12):1207-1212. DOI: 10.1111/j.1467-9280.2008.02225.x [RCT, experimental study, two experiments]
- White MP, Alcock I, Grellier J, Wheeler BW, Hartig T, Warber SL, Bone A, Depledge MH, Fleming LE. Spending at least 120 minutes a week in nature is associated with good health and wellbeing. Sci Rep. 2019;9(1):7730. DOI: 10.1038/s41598-019-44097-3 [Real-world, cross-sectional survey, n=19,806]
- Li Q, Morimoto K, Kobayashi M et al. Visiting a forest, but not a city, increases human natural killer activity and expression of anti-cancer proteins. Int J Immunopathol Pharmacol. 2008;21(1):117-127. DOI: 10.1177/039463200802100113 [Real-world, intervention study, n=12]
- Li Q, Kobayashi M, Inagaki H et al. A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects. J Biol Regul Homeost Agents. 2010;24(2):157-165. PubMed ID: 20487629 [Real-world, intervention study, n=12]
- Li Q, Kawada T. Effect of forest environments on human natural killer (NK) activity. Int J Immunopathol Pharmacol. 2011;24(1 Suppl):39S-44S. PubMed ID: 21329564 [Review]
- Li Q. Effects of forest environment (Shinrin-yoku/forest bathing) on health promotion and disease prevention: the establishment of Forest Medicine. Environ Health Prev Med. 2022;27:43. DOI: 10.1265/ehpm.22-00160 [Review, Forest Medicine]
- Siah CJR, Goh YS, Lee J, Poon SN, Ow Yong JQY, Tam WWS. The effects of forest bathing on psychological well-being: a systematic review and meta-analysis. Int J Ment Health Nurs. 2023;32(4):1038-1054. DOI: 10.1111/inm.13131 [Meta-analysis, k=36 studies, n=3,554]
- Antonelli M, Donelli D, Carlone L, Maggini V, Firenzuoli F, Bedeschi E. Effects of forest bathing (shinrin-yoku) on individual well-being: an umbrella review. Int J Environ Health Res. 2022;32(8):1842-1867. DOI: 10.1080/09603123.2021.1919293 [Systematic review, umbrella, 16 reviews]
- Wen Y, Yan Q, Pan Y, Gu X, Liu Y. Medical empirical research on forest bathing (Shinrin-yoku): a systematic review. Environ Health Prev Med. 2019;24(1):70. DOI: 10.1186/s12199-019-0822-8 [Systematic review, 28 studies]
- Danhof-Pont MB, van Veen T, Zitman FG. Biomarkers in burnout: a systematic review. J Psychosom Res. 2011;70(6):505-524. DOI: 10.1016/j.jpsychores.2010.10.012 [Systematic review, 31 studies, 38 biomarkers]