I don’t think that one can question the anecdotal benefits of walking through a woodland or forest. Away from civilization, it’s a time where one can really begin to relax, let the mind shut off from stressors, and let the eyes take in the wonderful sights. I know, from personal experience, that a woodland walk can bring about a state of calm and ‘inner peace’, and I often find myself exploring for hours on end only to realise I’ve been gone for half a day, am slightly lost, and need to walk home before it gets too dark.
Personal journeys aside, there is a growing amount of evidence to state how woodland and forest settings can be used to reduce anxiety, treat (as part of a wider range of things) stress, and maintain a general good state of well-being. In this post, I thought I’d look at a study from Japan that assessed how the practice of ‘Shinrin-yoku’ (‘experiencing the forest’) can impact upon the mental and physical state / well-being of individuals (for this study, this was 12 male university students of 21-23 years of age). The forest in question was an old-growth broadleaved deciduous forest, and the experiment was undertaken in the height of summer.
In order to quantify the benefits of Shinrin-yoku, the 12 men were separated into two groups of six. One group spent the first day in the forest and the other in a nearby city (to enable for comparisons to be drawn), and on the second day the two groups swapped locations. All 12 men stayed in the same hotel, which was located around one hour away from either site (by car). Before leaving for each location, they would have breakfast, and upon return they would have dinner. Once at each location, individuals had their day planned so that they would first spend some time in a rest room on the site, and then go on a leisurely but lone walk (a pre-planned route) within the study area. They would then return for lunch at the rest room on the site, before remaining in the rest room to look at the scenery (by themselves). During each day, all individuals had physiological data collected from them, including blood pressure and pulse rate, before and after each activity (at the hotel for breakfast, at the rest room prior to the walk, after the walk, before looking at the scenery, after looking at the scenery, and back at the hotel for dinner). The men were also asked to rate, on 13-point scales, whether they felt comfortable or uncomfortable, and calm or roused (agitated). They were also asked to rank how refreshed they felt. Again, these subjectivity tests were taken six times each day, for all individuals.
The results of this study are very interesting, as they show that the 12 men almost always preferred the forest experience in a subjective sense, and their physiological measurements backed this up. Benefits were particularly evident after the men had experienced the forest (after the walk and after looking at the scenery from the rest room), though even prior to going on the walk and observing the scenery there were marked benefits (as if the expectation automatically improved an individual’s perception of well-being, and their physiological condition). Below, we’ll look at specific data sets and what they show.

In terms of how calm the men were, one can clearly observe how the forest walk had a significant impact upon their state of mind, which was even more significantly impacted following a period where they individually took in the view from the rest room site. Alarmingly, the men actually felt slightly agitated after observing a city vista. However, we can observe how the impacts on the feeling of calm were largely immediate, as by the evening there was no significant difference between the two data sets. However, the fact that those who experienced the forest felt calmer in the evening than those who experienced the city is interesting, as it is the inverse of the morning’s results, and even prior to the walk’s results.

With reference to how comfortable the test subjects felt, we can clearly see how the forest experience (even when not on site, but eating breakfast at the hotel before heading out to the forest) made the men feel significantly more comfortable. The forest walk and scenery were particularly significant in raising the level of comfort within the men, whilst the city walk and scenery actually made them feel very uncomfortable. Following each walk and each observance of scenery in both locations, all men were significantly impacted by the experience, and the benefits and adverse impacts of these experiences have already been mentioned and can be seen in the graph above.

Looking at how refreshed the men felt throughout the day, we can again see how the forest experience trumped the city experience. Again, the refreshed state of each individual rose significantly after each experience, and individuals were significantly more refreshed after forest experiences (notably after observing the scenery). We can now see a trend, that observing a forest view from a point of rest is certainly very beneficial, and studies on how hospital recovery time is positively impacted by the view of trees from a window now start to make yet more sense (as mental well-being manifests in the physical form, via blood pressure levels, and on on).

Moving onto physiological impacts of a forest experience, we can see how the pulse rate of the men was, on average, lower before and after each forest experience, and also in the evening following the day’s experience. Only prior to the forest visit was pulse rate higher, and perhaps this was down to a form of excitement and / or apprehension (I am only speculating). Interestingly, the pulse rate of the men was quite markedly lower prior to the walk when they were awaiting a walk in the forest, suggesting that even the prospect of walking in a forest is physically calming, though curiously this doesn’t align fully with the men’s subjective feeling of calm prior to a forest walk. Therefore, we can observe perhaps a slight disparity between perception and actual physiological responses from the individuals to the prospect of a forest walk (perhaps, because walking in a city is more of the norm, they were more nonchalant about such a walk?).

As for blood pressure, we can once again see how it was lowered in both the top (systolic) and bottom (diastolic) readings. Yet again we can see how the forest walk and observance of forest scenery were beneficial for lowering blood pressure, though this was more significant with the sitting down and watching of the scenery. Perhaps this is to be expected, as walking, which is a physical activity, will raise blood pressure (even slightly). Importantly, this benefit progressed into the evening, where evidently the men were still more relaxed, albeit not significantly so.
So there we have it. Forests are good both physically and mentally! Please, however, bear in mind this is only a study of 12 men of the age 21-23, so it’s by no means a conclusive study, but it’s a useful indicator of how a larger study might turn out. Further to this, it was done in the height of summer in a broadleaved forest of significant age, so we must also accept the marked benefit may also be seasonal (and younger forests, perhaps also coniferous in nature, may elicit a different response). There may also be differing cultural responses, and therefore replications in other areas of the world would also be interesting to see. I’ll let you look over the graphs again so you can form more conclusions for yourselves, though I hope this has been of use for many who are reading this. For me, it certainly aligns with my own experiences from walking through broadleaved woodlands. And I write all this as I overlook miles of fields and woodlands from my bedroom window, which has also had a very calming impact upon me – that is without doubt.

Source: Tsunetsugu, Y., Park, B., Ishii, H., Hirano, H., Kagawa, T., & Miyazaki, Y. (2007) Physiological effects of Shinrin-yoku (taking in the atmosphere of the forest) in an old-growth broadleaf forest in Yamagata Prefecture, Japan. Journal of Physiological Anthropology. 26 (2). p135-142.