This ex-gangster and school drop-out has fostered a loyal clientele at the gym he started from nothing

Warning: This article contains references to suicide. 

If you ever see Mr Luke Yeo out and about, you may find yourself wanting to give him a wide berth. 

At first glance, the 33-year-old is physically intimidating, his hulking frame covered in tattoos and broad shoulders bulging with muscle.

It is a look he has worked on since he was a teenager – back when he was known as the "monster" of the gang he was in. 

"When you get into fights, you have to be bigger than someone or you learn how to fight. Or you have to be daring enough to use a weapon to hit somebody," said Mr Yeo. 

"The best way was to train to get size, so nobody would want to fight (you)."

Almost two decades later, what started out as a bid to build a reputation for being a fearsome gang member has evolved into his life's work as a competitive bodybuilder and owner of Unstoppable Fitness, his four-year-old gym in Shenton Way. 

I'm not generally one to judge a book by its cover, but when I first met Mr Yeo over a video call, I wasn't quite sure what I would have in common with a gym owner whose physique takes up a good portion of the frame. Admittedly, I grew up bookish, and was a reluctant entrant to the fitness scene only as an adult. 

But right away, Mr Yeo shared that he too started out as a skinny teenager. At 13, he was already being bullied for looking "like a stick", standing at 1.68m tall and weighing 42kg – about half what he weighs now.

He would go on to run with a gang, drop out of secondary school and, at his lowest point, spend time in prison, before discovering in the gym the camaraderie he had once sought in the wrong places. 

During our second meeting at his gym, this time in person, I was nursing a cold and feeling a bit out of place as mostly male members around me moved through their sets, the occasional clang of weights and grunts of effort punctuating the high energy music pulsing through the speakers. 

When I raised the "alpha male" or "gym bro" culture sometimes associated with certain fitness spaces, Mr Yeo said that he understood where the stereotype comes from and that gyms once felt intimidating even for him. 

In his experience, however, it is often the "biggest guys", covered in ink, who are the most willing to help a stranger in the gym.

Naming his gym "Unstoppable" was not about just catering to the strongest, he added, but about encouraging any person who walks in to give it a shot, even when they may feel they have no one backing them up.

"I came from nowhere, no parents, no business partner, no investors, then I started something. Not to say that I'm somewhere now, but with just interest and hard work, I built a path for myself."

FIRST GANG, TATTOO AT AGE 13 

Mr Yeo became a child of divorce at a young age. Growing up, his father's drinking and gambling habits meant that he and his older brother were largely raised by their grandparents. 

His mother, too, was very often absent. He recalls seeing her only three times in his entire life – the first in court when his brother was being sent to prison, and the second when his grandmother died.

"The third time when I saw her was before she committed suicide," said Mr Yeo. 

The brothers were squeezed into their grandparents' three-room flat with four other relatives. Still, Mr Yeo recalled being "very happy" with the elderly couple, despite the big age gap and the fact that they spoke only Teochew, which the boys learnt to speak. 

"My grandma always used to tell me: 'Whatever I have, even let's say S$1 (US$0.79) – the S$1 is yours'."

But at secondary school came the first signs of trouble. On his first day, some older students asked him to use his S$2 allowance to buy them hot dogs and soy milk, and would harass him daily. 

"They brought me up to the car park. I still remember the car park's edge, they placed my hand there and stepped on it, opened my mouth, took grass and put it in my mouth and asked me to chew."

Not wanting to trouble his elderly grandmother, he turned to gangs for protection.

His first gang consisted of a group of five classmates who marked their bond with a tattoo inked at Peninsula Plaza. At 13 years old, it was Mr Yeo's first ink: a Japanese thunder god in the centre of his back – one of the few designs he could afford with the S$30 he had. 

"When I was young, the more tattoos you had, the more fierce you were. So we tried to put on as many tattoos as possible," he said. 

In Secondary 3, when he transitioned to long pants for his school uniform, he began inking his leg as well – "from my feet all the way up to towards my glutes".

Today, Mr Yeo's right arm is also an Amazon jungle spanning a jaguar, gorilla and parrot, while his left is a tribute to characters from the Batman universe.

At this time, he also began skipping school to play computer games with friends, eventually dropping out and finding peers instead in the gang.

"Most of them came from a broken family, and we could all relate (to each other)," he said. 

For the first time in his life, Mr Yeo also found himself supported in ways he'd never known before – even if the support may not have been of the right kind. 

"The first time I got in trouble, I made a call to my gang leader and 60 people came," he said. "So you felt powerful. You felt like someone had your back."

Over the years, Mr Yeo would get into trouble with the law repeatedly, including for fighting at clubs.

It all came to a head in 2015, when the police turned up at his grandmother's flat in Toa Payoh to bring him in for illegal gambling activities.

As the commotion turned heated, Mr Yeo's then 86-year-old grandmother got on her knees and begged the police not to arrest him. 

“I told her to stand up, don't do this. I told the police officer: 'You want to catch me, bring me out of my house and cuff me. Just don't let it be in front of her'.”

At 22, Mr Yeo was sentenced to 12 months' jail for an offence under the Remote Gambling Act and separately placed under a police supervision order for three years under the Criminal Law (Temporary Provisions) Act, a decades-old law which allows for the detention of people linked to certain criminal activities, such as secret societies, without trial.

A NEW COMMUNITY AT THE GYM 

Prison was a sobering wake-up call for Mr Yeo.

"You're cut away from the world. Nobody knows that you're alive. Basically, you're erased," he said. He recalled the first time he was able to leave the premises: "I felt that the sky looks so blue, even the air smells so good."

In the time he had been away, new smartphone models had been released, a new train station had been built near his home – and, most painfully, his grandmother had died. 

Years of gang culture had taught him not to show any weakness, including by crying. But when he received the news of his grandmother's death, the tears fell immediately.

"That was one of the hardest times in my life," admitted Mr Yeo. 

He also learnt that his grandmother's flat had been sold, so he no longer had a roof over his head either. He eventually had to move into his father's government rental flat.

With only S$200 to his name, no education qualifications past primary school and no clear path forward, he felt hopeless. A previous attempt to sign on to the army after completing Basic Military Training had already been rejected because of his history with the law.

He felt all he really had was his body. 

Having trained largely on his own and done ad hoc personal training stints at a friend's gym previously, Mr Yeo began taking on freelance personal training clients on Carousell, using pictures of his own physical transformation to promote his services.

At the start, his heavily inked appearance drew scepticism.

"Now tattoos are more visible, but previously, everybody would look at me like an advertisement. So of course, the clients felt uncomfortable, and there wasn't much trust," he said.

Mr Yeo worked hard to overturn negative misconceptions by proving himself through his commitment to his clients and the skill set he could offer them. Eventually, it paid off. 

Now, in a decade of being a personal trainer, he has trained more than 200 clients – ranging from gung-ho 15-year-olds just starting out, to clients in their 70s building the strength to manage daily activities, some of whom have stayed with him for 10 years.

He also threw himself into competitive bodybuilding. This was not just about the accolades for Mr Yeo, but also the benefits of the intensive daily routine of meal preparation and focused training.

"Cooking takes a lot of time. Every three hours I have to eat," said Mr Yeo. "I have to train and do two hours of cardio (every day)." Throw in caring for and walking his beloved dogs, and that easily filled up his entire day. 

He credits this demanding routine with clearing his mind of all the turmoil and trouble it had been steeped in for years.

"I (became) very focused and could see the changes in my body. That's when I started to feel: 'Okay, this is what I'll do. At least I'm doing something good for myself now'."

He started taking steps to formalise his freelance personal training business, applying for a loan, hunting for a physical space and negotiating rental rates for a gym. Soon enough, Unstoppable Fitness was born.

In the early days, Mr Yeo operated as a one-man show. He single-handedly planned and ran training sessions with clients, took care of administration and marketing, and even rolled up his sleeves to do cleaning and laundry.

"As a business owner, any issue is your issue," said Mr Yeo, adding that he had to learn everything on the job without any formal training in business or marketing. 

At first, he tried to lower his prices as much as possible to reach as many customers as he could, as well as taking on any customer that came his way to pay the bills. However, this proved to be an ineffective marketing strategy, and also led to him overextending himself to the edge of burnout. 

"The worst part was when the funds were not coming in, and I was bleeding (money) every month. I kept asking myself: 'Why am I still doing this? Should I call it quits?'" 

Despite the odds stacked against him, sheer determination and a refusal to give up kept Mr Yeo pressing on doggedly.

"I don't regret it, because if I didn't have that experience, I don't think I could last till now as well." 

Eventually, his sincerity won over the small number of clients he had managed to gather, and the referrals started to stream in. Mr Yeo recalled a conversation with a client that put into perspective what he is trying to build with his business. 

This client had medical issues and said that coming to the gym was an escape for him while he worked towards losing weight. 

Something clicked in Mr Yeo, who had also found an escape in the gym as a lost teen. "I was out there getting in trouble, getting into fights and all. And the gym was somewhere I could belong to."

That same client also showed Mr Yeo how his work was more than skin deep, as the client's improved health had also led him to feel more confident and better his relationship with his wife. 

"I always thought training was just physical. But being a trainer is being a part-time listener as well," said Mr Yeo. 

"Some people may have had a bad day at work or (family) issues, and they come here to release."

STILL A 'SMALL KID WITH A WIDER BODY'

It may seem like the perfect, happy ending at first: the troubled ex-gangster has turned his life around and found new purpose in his burgeoning business. However, Mr Yeo noted that he is not quite out of the woods just yet.  

In recent years, a string of gym closures has laid bare the pressures operators face – high rents, a saturated market and changing consumer demands as people settle into post-COVID hybrid or flexible working arrangements. 

Mr Yeo now has a small team of trainers and staff to share his load, but he is still in the gym meeting clients six days a week.

Right now, he dreams of setting up another Unstoppable Fitness with a better location and updated amenities to appeal to more members. 

He is also hoping to step onto the competitive bodybuilding stage once or twice more while still in his prime, though managing a rigorous training routine for himself is difficult these days when he's already shouldering the constant stress of operating a business.

While most of the burden falls squarely on his shoulders, Mr Yeo noted that he is still close with his older brother. The 34-year-old, also a personal trainer at Unstoppable Fitness, now lives with Mr Yeo in Toa Payoh – near the three-room flat of their childhood, where they once crammed in with six other people. 

Despite being a self-proclaimed introvert, Mr Yeo animatedly showed me around the same brick-coloured walls of the estate and the basketball court where, as he put it, "the naughty people" would gather.

On a bench facing the nearby refreshed playground – now three storeys too high to climb on top of like he did as a boy – Mr Yeo showed me the only childhood photo he could find: As a small boy at his kindergarten graduation, dressed in a blue cap and gown and grinning shyly at the camera. 

"My face didn't change much. It's just that I look like a small kid with a wider body now," said Mr Yeo, with the same boyish grin. 

He had asked around with former schoolmates for more childhood photos of himself, but no one had any. He had missed too much school to have made it into any secondary school class pictures. 

But one of his proudest moments was being invited to speak to 40 students about his career as a personal trainer nearly two decades later – the first time he had even set foot in a school auditorium. 

"I felt embarrassed," confessed Mr Yeo. "I've (never even graduated) school and I'm here, trying to give advice to other people. I felt happy and sad at the same time." 

When I asked if he thinks his late grandmother would be proud of all he has achieved, Mr Yeo was somewhat sheepish. 

"I think some part yes, some part no," he said, though he still takes to heart her lessons on being a good person who helps others.

He strives to carry that into his work today. Last year, Unstoppable Fitness took part in a fundraiser for the Rare Diseases Society of Singapore in 2025 where Mr Yeo and his trainers had to, as a team, perform 1,000 push-ups.

As part of that fundraising effort, he found himself posing in a photograph alongside local celebrity, the actor and model Paul Foster.

Even now, disbelief rang clear in his voice as he described the event. "Someone like me, suddenly taking a photo with an actor now," he said, incredulous.

"I cannot choose my parents, I had no investors or partner, but I got to choose my own path. Not to say I'm getting very far, but to have kids or people say they want to be like me –  in terms of my body, and me as a person – at least, I think I can inspire some people now."