World champion Greek athlete Mr Eleftherios Petrounias has his sights firmly set on gold in Rio.

Glasgow, October 2015. The final of the still rings event at the World Artistic Gymnastics Championships is under way. There is silence in the SSE Hydro as Mr Eleftherios Petrounias follows a ritual of rubbing magnesium chalk into his palms, making a few deft movements with his hands and eyes and finally kissing the cross around his neck. Slowly, the reigning world and European champion counts the steps he takes on his way to the rings. Then, with the grace of a swallow, he opens his tree-trunk arms and launches into the air. The look on his face is one of complete, Spartan-like self-control.

In reality, Mr Petrounias’ life is not so far away from that of the Spartans (Ancient Greeks who led rigorously self-disciplined, austere lives). There is a saying in Greece that translates as “those who live with little and work hard are disciplined and committed with all their spirit and body to their aims”. The 26-year-old athlete is the embodiment of these words, a man who has turned his life over to the singular purpose of reaching the highest level in his sport. Such is his standing in the gymnastics world that in February 2015 the committee of the World Federation gave his name to a move on the still rings. It was a huge honour for both Mr Petrounias and his country.

His next big goal is the gold medal at the Olympic Games in Rio, the only one missing from his collection. And his latest tattoo is a daily reminder of his purpose: a cross that forms the words “still rings”, with the two words sharing the letter “i”.

We meet shortly after Mr Petrounias has finished his afternoon training, six weeks before the Games with the temperature in Athens at 40°C. Although this will be his first Olympic Games, Mr Petrounias is confident he has what it takes to win. “My only big opponent is myself,” he says. “In a big event, the things that matter are the anxiety, the pressure, the moment. If I do the right moves and if I do what I do every day during my training, then I have nothing to fear.”

His days begin at 8.30am, when he takes his dog, Champ, for a walk. “I do the same at noon and night,” he says. At 10.00am he arrives at the Aghios Kosmas training centre for a morning’s session that lasts until noon. After a two-hour rest, he continues training until 6pm.

Rings gymnastics requires superhuman levels of upper-body strength. You only need to look at Mr Petrounias’ arms and shoulders to see that. Surprisingly, though, there isn’t a great deal of weightlifting involved in the average ring gymnast’s training regime. Most of Mr Petrounias’ time will be spent using only his own body weight for resistance, and a few hours a day will be given over to mastering the routine itself and practising balances, dismounts and holds.

While his training is regimented, he is more flexible with his diet. “I care about my diet, but don’t deny myself anything,” he says. “In Greece, we believe that you can eat everything but in the right amount. I include a lot of protein in my diet because the training is hard.”

A close-knit family helps him stay focused. “My mother, my brother, my uncle, who is like a father to me, and my godmother are my most faithful fans.” he says. “They support me with a lot of love, regardless of the result. I owe them a lot.”

The pre-competition ritual and prayer are tributes to his father, Mr Panagiotis Petrounias, who died last year. He was a customs agent who first took him to the gymnasium at Nea Smyrni in Athens at the age of four so that he could burn off some excess energy.

“I was amazed by the all equipment, the sponge pits, the springboards,” he says. “I started jumping everywhere. From that moment, I didn’t care about anything else. I just wanted to be at the gymnasium all day long. I felt like I was born for this.”

Then, suddenly, aged 16, he went into his trainer’s office and called his mother. “I do not want to come here ever again. I want to stop,” he said. His mother was surprised, but told him, “Whatever you want.”

“I had a problem with my elbows,” explains Mr Petrounias. “I was undergoing treatment. It was exhausting. I just wanted to live like other children my age. I was bored with trying not to get hit or injured. I was bored with thinking about what might happen if I lost an event. I didn’t want to be a champion who doesn’t have a normal life. One of the first things I wanted to do was to buy a motorbike, something that was off limits. I didn’t want to worry about not getting hurt and missing a training session. I started to go out a lot with my friends, have fun. I even did parkour [the largely outdoor adrenaline sport that includes leaping between buildings with no safety net]. By the time I turned 17, I had lost all my balances.” In gymnastics, balances are the fundamental positions of a discipline.

So why did he come back? “I had changed. I had started to lose myself… I had to fail first in order to succeed. Failure only serves to motivate you. If both you and the people you have around you believe in your abilities, then it is certain that you will succeed.”

A top-level gymnast’s life is not easy, especially at the start. As well as all the training, there’s a huge financial commitment to cover travel costs, among other things.

“Until the day you start to win medals, you don’t have anything,” says Mr Petrounias. “Not even the money to buy petrol to go to training. There is some money available for transport, but not much and it’s slow to come through. What can you do with 300 euros that you get after six months? But when and if you succeed, then the funding from the federation gets bigger and if you are lucky, like me, you’ll find some sponsors.

“At the level I’m at now, I can afford an apartment of my own. I am financially independent, but athletics doesn’t ensure you financial security for life. If you’re a non-professional athlete, God help you, because you spend all your day for your sport, but it doesn’t guarantee your future. This is especially so in rings, which is not like football or basketball or running.”

Once Mr Petrounias started to win competitions and eventually the European and world titles, things got a bit easier. “My life changed in all aspects, both financially and psychologically. Everyone recognises me in the street now, which is really great. It gives me the will to keep trying for the next success.”

Mr Petrounias lives alone. “I do all the washing, clean my house and pack my own luggage,” he says. “It is exhausting, but I wouldn’t change my life with anyone I know. By the age of 25, I had already travelled to more than 40 countries. It’s great, because I love travelling. During these foreign trips, I’ve become good friends with other athletes.”

With one eye on the future, Mr Petrounias is studying communications and marketing at Athens University of Economics and Business. He will switch his focus to his studies once the Olympic Games are over, because he believes that trying to do two things at the same time is too demanding.

“I like competition, so I believe I’ll find something else in which I will strive to get to the top,” he says. “I am interested in investments and commerce. I believe that I could be a successful entrepreneur. My dream is to create a centre that can help more people get involved with sports. But the economic situation in Greece is going to make that difficult.”

In his free time, Mr Petrounias likes visiting his family or going for a coffee or “a little” wine with his friends. After a big win, the Greek champion usually allows himself a night out and eats all the things he can’t have when training. When the night’s over, he pays the bill.

“I have a group of friends I’ve known since I was five years old, and two athletes who have been with me in the national team for about 10 years,” he says. “There are some athletes from foreign countries with whom I’m friends, and we have a great time before the games. But when you arrive in a foreign country, your mind is entirely focused on the upcoming event. Being able to forget this for a while and have fun with other athletes helps you a lot. It’s far better than being shut up in your hotel room.”

So what is the secret of his success?

He laughs. “There is no secret. Clearly, what’s needed is a lot of work and patience. My motivation comes from my trainer and from my foreign opponents. In the Greek team, we may not have lots of achievements, but we have great athletes. We are friends and help one another.”

Mr Petrounias is already dreaming about his life after the Olympic Games. “I am considering just disappearing, going outside Greece, to somewhere exotic,” he says.

Even Spartans need a holiday.