Crossing a threshold. That is how Chiara Cenedese, a 35-year-old from the province of Varese, describes the experience of entering a wood body and mind. "It's as if something sacred happens. It's like coming home," she says.

And indeed, for Chiara, her relationship with everything wild has truly been a point of return: "I wanted to be financially independent, I wanted to build a career," she recalls. "And I did: I spent twelve years at a multinational in senior roles. But in the city I felt a sense of despondency, I felt dissociated. After a major nervous breakdown, complete with a psychiatrist's note signing me off for six months, I decided to reconnect with nature. It was my salvation."

Massimiliano Corrà, 53, originally from Trentino, also tells of a similar experience. After five years in Chile and a working past in the construction sector, he felt a powerful calling: "Trees have a different kind of energy. The relationship with them helped me bring order to my life."

Chiara and Massimiliano are well acquainted with the benefits of contact with nature. More than that, in fact: they are both certified forest bathing guides — in Italian, bagno di foresta — a green therapy imported from Japan that scientifically recognises a beneficial effect on the human body and health in certain types of trees.

The history of forest bathing and Natural killer lymphocytes

Forest bathing, originally called Shinrin Yoku and later translated by English speakers as forest bathing, is a practice that originated in Japan in the early 1980s.

"In Italy, the first scientific studies began to filter through about a dozen years ago," says Marco Nieri, a bioresearcher specialising in ecodesign and habitat health, and a certified Fth Forest therapy hub trainer. "There was talk of a wellness practice that had been launched by the Japanese Forestry Agency to reduce stress levels in the population. It was only from 2004, thanks to Japanese researchers Qing Li and Yoshifumi Miyazaki, that the way spending time in the woods produced very intense physiological and psychological effects began to be studied scientifically."

Among these, significant findings included the "reduction of the stress hormone, above all salivary cortisol, the regulation of blood pressure, a reduction in heart rate and greater regularity of the heartbeat," explains Nieri, "but also an increase in the activity of the parasympathetic nervous system, which governs biological functions, and a reduction in the sympathetic nervous system, which is responsible for emergency responses. And then a reduction in the perceived sense of anxiety, depression, anger, fatigue and confusion, and an increase in the feeling of vigour."

But the most important discovery concerns a positive effect on the immune system: "Specific components of the essential oils produced and released by certain trees, called monoterpenes or Phytoncides, act through a dose- and time-dependent mechanism to increase the number and activity of Nk lymphocytes — the Natural killers that play a role in controlling tumour cell viruses in the human body."

From Japanese trees to Italian ones

To make the most of the potential of forest bathing, one must therefore walk through the woods, inhaling for several hours this air naturally enriched with the therapeutic volatile substances emitted by trees. After just a single three-hour session, researchers explain, the benefits to the immune system can last up to a week, while by managing to accumulate ten or twelve hours in the woods — even over several consecutive days — one can achieve an increase of fifty per cent for an entire month.

But not all trees are equal, specifies Nieri: "Together with my colleague Marco Mencagli, with whom I co-wrote the book "La terapia segreta degli alberi", we carried out research and realised that in our own forests we can achieve the same effects as Japanese forests. In Italy, the beech, the chestnut, the holm oak, the cork oak and the stone pine are strong emitters of monoterpenes."

From this research, the two investigators created dedicated routes and trails for forest bathing, such as at the Oasi Zegna in Trivero (Bi), which since 2015 has been the first green route specifically designed for forest bathing, and at the Parco del respiro in Fai della Paganella in Trentino, where it is also possible to get a taste of "Bioenergetic landscapes", the technique devised by Marco Nieri that studies the effects of plant bioelectromagnetism on the human body.

For a forest bathing session one can therefore rely on a facility with dedicated routes or walk independently, moving through the holm oak woods of Sardinia or southern Tuscany, between Livorno and Grosseto, or through the beech forests, from the Gargano to the Umbrian forest. One can also walk through the chestnut woods of Piedmont or the Norway spruce forests of South Tyrol.
A useful resource in this case is the website Parks.it, where a list of national and regional parks can be consulted.

Getting lost in nature to find yourself again

"The forest does most of the therapeutic work," says Massimiliano Corrà, a certified guide for Parco del respiro, with characteristic modesty. But the truth is that the forest bathing experience is incomplete without someone able to offer sensory experiences that foster a relationship with nature.

The guide leads participants, through very simple practices, to an awareness of what we are in that moment — here and now — as physical beings within the forest. And we become aware of the environment and of the forest's main inhabitant: the tree.

Massimiliano Corrà

Of course, there are a few basic rules to follow in order to offer a genuine forest bathing experience: "The first point is that there must be tree cover — that is, you need to be able to spend most of the time beneath the forest canopy in order to inhale these volatile substances," explains Chiara Cenedese, an independent guide known on Instagram as @chiara_madreselva, who is also active in Foraging — the identification and gathering of edible wild plants.

"Personally, I choose an ideal forest that is easy to reach and accessible to everyone: you shouldn't have to walk a long way to get there, precisely in order to offer the experience to people of all ages, and for that reason it's helpful to have a car park nearby."

Each session lasts on average three to four hours, ideally with phones switched off.

"I always begin with an introduction in which I say there is nothing right or wrong, and that my role is simply to open a door. And I warn participants: for some it may be a relaxing, creative, playful experience. But there are also people who cry during the session, because they realise they need to process deep emotions. And the forest is a safe place in which to experience all of these emotions," Chiara recounts.

For Massimiliano, "it is a slow invitation to live in the present moment. Today we are very much projected into the future and we struggle to be present with what is here. We use the approach to the forest to activate our five senses, going deep, slowly, and stimulating curiosity."

The effects of tourism and climate change

Perhaps the greatest criticism levelled at forest bathing is that it is not quite as sustainable a practice as it might seem. The concern here focuses on the number of people being introduced to natural environments that are less well known and less frequented. Something easily resolved with a little respect, says Chiara Cenedese.

"In reality, forest bathing is good for tourism and tourism is good for forest bathing," adds Massimiliano Corrà. "Simply promoting a return to and reconnection with nature as a form of personal wellbeing means engaging in prevention. We are spreading an important message, which is to get moving, to step outside the norm and to go into the forests, which have so much to offer us from a therapeutic and scientific perspective on how to experience things."

Climate change also affects forest bathing. "I am witnessing a progressive spread of many plant diseases," warns Marco Nieri. "And the situation is not helped by the arrival of significant infestations resulting from a weakening of the plants' energy state. So I am seeing more and more sick plants, dry plants in particular, which make me think that the climatic conditions really are different: rainfall that is less frequent yet more intense, which does not nourish the soil. None of this is good for the trees."

The first step towards protecting our natural habitat is raising awareness of the problem. Forest bathing serves this purpose too. "Let's plant as many trees as we possibly can, let's go into nature and restore this contact," urges Nieri.

"Let's learn to love and recognise what surrounds us," concludes Chiara Cenedese. "Let's return to joyful, concrete actions. Joy must be a fundamental part of these practices — first and foremost for ourselves, otherwise we risk creating generations of people in burnout, whether from years of exhausting work or from extreme ecological activism."