Gian Luca Innocenzi swings open a custom-made, garage-size steel door to reveal his new creation. In the high-ceilinged showroom, sunlight streams in from above and ignites the boughs of a tree. But this is no ordinary tree: it is a seven-metre tall, moulded-concrete sculpture with “branches” that curve upwards. In fact it is the centrepiece of a gym built for the outdoors and it is Innocenzi’s brainchild, four years in the making.

“I wanted something that would harmonise with nature,” says the fitness and wellness expert. “The more beautiful something is, the more you want to use it.” The tree (a prototype of the final design) is surrounded by islands of push-up handles and elastic resistance bands; sit-up benches and balance boards; monkey bars, trapeze rings and pulley ropes.

But the finished product belies the arduous story of how it came to be. It was during a session in the drab indoor gym of a Maldives resort – while all the other visitors enjoyed the sunshine – that Innocenzi dreamt up an outdoor workout space that would integrate functionality with a clean aesthetic. He imagined it offering equipment versatile enough for diverse fitness practices. He revealed the concept to Vito Di Bari, a Miami-based Italian whose design firm specialises in forward-looking monuments and art installations for cities. “I was sure Gian Luca would be successful with his idea,” says Di Bari, “so I wanted to help him make sure that our parks weren’t invaded by these horrible workout machines that look like Transformers.”

Di Bari began with the notion of equilibrium “between ourselves and the nature around us – and nature for humans is symbolised by the tree”. He took the building blocks of humanity – cells – and designed a towering tree with branches in the shape of cells, a fusion of humans and nature. The team called the project MyEquilibria. The final prototype looks a bit like it might be a prop in a Hollywood sci-fi film but it’s certainly eye-catching – and will surely be a hit with anyone who liked Avatar.

Innocenzi describes the central tree as “a sort of totem” but as well as attracting attention it also acts as the anchor for the multi-use equipment fastened to its trunk, which was developed in collaboration with the Miami-based Wellment company. But it was the sculptural tree itself that proved to be the initial problem. An outdoor gym must be made to resist the pushes and pulls of human bodies as well as decades of battering by the elements. Knocking on factory doors across Europe, time and time again Innocenzi found himself rebuffed by manufacturers who believed that the project required a material that did not yet exist.

Then he met Alfredo Tasca, founder of street-furniture manufacturer Metalco and a designer who believes in city furnishings as tools of social integration. The inventor and the industrialist each recognised in the other a worthy partner. Based in Castelminio di Resana, a small town in the industrialised region of Veneto in Italy’s northeast, Metalco creates everything from benches to bike racks, rubbish bins to plant holders. Six months prior to meeting Innocenzi, Tasca had begun manufacturing playgrounds and saw that MyEquilibria was an evolution of that work. “I liked the social aspect of bringing people together.”

Realising that this project would require an extraordinary material, Tasca turned to Il Cantiere, the innovative concrete company renowned for bringing complex projects (such as Zaha Hadid staircases) to life. He partnered with the firm to create a material capable of turning MyEquilibria into a reality.

It took a year to develop a suitable material – an ultra-high-performance concrete mixed with resin and rocks reinforced with carbon fibres – that would prove up to 10 times stronger than regular concrete and as flexible as metal. This material was then moulded over a steel frame and MyEquilibria was brought to life.

As cities struggle to keep their growing populations healthy, government plans increasingly include the construction of outdoor gyms among their wellness projects. These adult playgrounds are not only a solution to rising obesity levels: they are also relatively democratic, offering fee-free equipment that brings together all levels of society with little needed in the way of supervision and maintenance. Tasca and Innocenzi are now honing their pitch. MyEquilibria will come in modifiable configurations from 50 to 500 sq m, the largest accommodating up to 100 people. Priced between about €50,000 and €250,000, depending on the size, the gyms are aimed at city parks and public beaches, as well as corporate campuses, hotels, resorts and private homes. Production will begin in January 2016; several cities in Italy’s northeast have already expressed an interest but the team behind MyEquilibria has ambitions far beyond the country’s borders.

In the 19th century, urban parks came to be appreciated for their health benefits as much as for their beauty by citizens choked by the polluted air and gritty reality. In the 1960s, fitness trails – woodsy running paths dotted with workout equipment – proliferated in Europe as exercise and nature started to gain an affinity. Now, when we are desperate to reclaim nature and govern our health, we may soon find ourselves gathered around a concrete tree.

Notes: Sitting comfortably

When Alfredo Tasca founded Metalco in 1984, he claims that no one else was manufacturing street furniture for the urban environment and that cities were throwing wooden planks together and calling them benches. While many may disagree, Metalco’s influence on the designs that shape our everyday experience in today’s cities is undeniable. The huge manufacturing headquarters is filled with a team of 100 operators, artisans, researchers and designers. They are creating the range of urban outdoor decor and fixtures, visible in 4,000 cities, in steel, aluminium, wood and – with the recent collaboration between Tasca and Il Cantiere – ultra-high-performance concrete.

Tesla Supercharger stations and interactive information points for the Paris Métro are built alongside well-designed billboard frames destined for Brussels and recycling bins for Venice’s airport. More than 5,000 sq m of solar panels installed on the rooftop generate enough solar energy to power Metalco’s entire operation. Tasca’s passion is communality: benches, his favourites, are “a tool for sociability”, part of what he calls the “outdoor urban living room”.