We’re sitting ringside at Holyrood Boxing Gym, the centre of the 42-year-old former British ABA Lightweight Champion’s world.
To the right, another ring sits empty, in the distance a forest of heavy punchbags hang from the ceilings.
It’s early in the morning and the gym is deserted, yet somehow it’s easy to imagine it crammed full of bodies, all pummelling away in response to Bradley’s shouted commands.
The man himself is a fast-taking dynamo, regardless of the fact we’re in reflective mode this morning.
His ethos is simple: “Your might is your right,” he says.
It’s something he learned from his mum Patricia who died in 2012, and as we chat, he reveals her passing was “the most important thing that has ever happened” in his life and one that left him “devastated”.
“You never get over that,” he says. “I still see her wee face, hear her whispering in my ear.
“Mum instilled in me a desire to always do my best. She told me, ‘Don’t look at what people have, look at what they’ve not got’. That’s the one thing I have as yardstick in my life now,” he says.
It wasn’t always like that and there’s regret too when Bradley talks about his mum. His past is well documented and landed him a prison spell as well as an episode of Danny Dyer’s Deadliest Men.
“Boxing got me through the very hard periods where I went off the tracks,” he reflects.
“I was born in Moredun in the late-70s, when there was nothing there.
“It was an area where you grew up with the mentality that you had to go and take stuff and I was predacious due to a lack of education.
“Everybody knows my back story; about going to prison and using boxing to transform my life, but when I was in prison it destroyed my mum and I made her a promise...
“You have to remember, at the time I was a young boy.
“From 15 to 19, I went through the stratosphere, got involved in protection rackets, the security industry, I was a nightclub promoter... the mistake I made was shutting everybody else down.
“However, the minute I landed in prison, I realised I was with a bunch of imbeciles.”
Released from prison with four more Highers than he had attained at St Thomas Aquins High School some five years earlier, Bradley determined to turn his life around.
Even now though, more than two decades on, he accepts that past will never be far away.
“It’s always with me but I don’t have to atone myself for anybody. The things I did, they were wrong, but I understand why I did them, because I had f**k all.
“Of course, I regret them. I have a daughter and a wee boy who is like a son to me, and I want a better society. That’s why I do what I do.”
What he does is work with the community, people who are economically and socially alienated, from his Holyrood Gym base, running boxing/fitness classes for children, women, adults, the unemployed and the homeless.
Thoughtfully, he remembers, “My fiancé Emma and my wee daughter Tiger Eva could see I wasn’t coping well after my mother died.
“I used the gym to escape and knew I wanted to do something in her memory.”
That event, Pads for Charity, would see Bradley make the Guinness Book of World Records after he spent 24 hours in the ring as 360 people each engaged him in nonstop rounds of pads - a new world record that almost killed him and proved pivotal to him being cast in Trainspotting 2.
He says, “It wasn’t good for my health but I raised £42,500 for charity, however, the big thing for me was that I got a Guinness World Record in my mum’s name.”
Two of the people who stepped into the ring with him that day were film director Danny Boyle and screenwriter John Hodge, both were working on Trainspotting 2 with Irvine Welsh, a pal of Bradley’s.
“Irvine brought them up and they took part in the event. I met them the next again morning, showed them around some sights in Edinburgh and Danny Boyle said, ‘I want you to audition’.”
The part was that of gangland boss and sauna owner Doyle, who puts the frighteners on Renton and Sick Boy when they dare to cross him.
“I thought, ‘I can do that. No problem’,” he says, “Gallus as anything. I thought, ‘I’ll get in there, read a script, adapt it and just be myself; everybody else seems to just be themselves in every film you ever see’,” he adds, fully aware of the irony.
“I gets there, reads it, it’s not that long a script, went in and... played it all wrong.
“I was too aggressive, it should have been played subtle. I came out and sent Danny a text saying: ‘I f**ked it up’.”
Two days later at the book launch for Welsh’s novel The Blade Artist, Bradley met Boyle again and asked for another chance.
“I made a show reel and sent it to him... he said, ‘You’re in. You’ve got it’.”
On the back of Trainspotting, Bradley has been asked to write a book or two, been offered representation by acting agents, and even a role in Outlander... “But it turns out they give anybody parts in Outlander, don’t they?” he laughs.
So far, no one has been able to tempt him back onto the screen.
“Thing is, all they would want me to play is the Scottish hard man. I’d be typecast,” he says realistically.
Remember the word ‘amateur’ right at the start of this piece? This is why it’s important.
“I have been in this game nearly 40 years now. When I started, I saw it as a way out of the ghetto,” explains Bradley.
“But there’s a huge difference between amateur boxing and professional boxing; one is not a sport, it’s a business that fools young kids into thinking it is a way out, of making money by getting their head punched in - that’s professional boxing.
“I discovered that the hard way. I turned professional, it’s a world where things are stacked against the boxer, a young kid can make more money on a building site than they ever will in a professional boxing ring getting their brain shook and their money took.
“I hate the professional sport, I don’t have any professionals in my gym, for me, the amateur sport is a better thing.”
For more information about Holyrood Boxing Gym visit www.facebook.com/HolyroodBoxingGym/ or follow @holyroodboxing on Twitter