Harry Potter star Josh Herdman has said martial arts changed his life after he became a “party animal” following his success in the film franchise.

Herdman, 30, was just 13 when he was cast as Gregory Goyle in the wizarding series, and said he found he needed discipline after the money he earned from the movies funded a party lifestyle.

Harry Potter premiere
Josh Herdman at the world premiere of Harry Potter and the Philosopher’s Stone (Yui Mok/PA)

He told the Press Association: “If I’m honest I was a party animal, I was, like many young people are.

“But I had enough of it so I decided I was going to get fit and I knew I needed something to focus on and martial arts did change my life.

“You need a discipline, you need a tenacity, you need drive to keep at it.

“When you start you’re getting hammered, you are a novice.

“That is what a lot of people who start martial arts can’t get through and they don’t like it but it was exactly what I needed and it taught me a discipline, which I needed at the time, and a focus, it changed everything for me.”

Asked if he thought his lifestyle stemmed from being successful when he was so young, he said: “I don’t know, it was the people I was hanging around with and you have money.

“It was just what I was doing and I had enough of it so I gave it up and started to focus on my fitness, I quit smoking and I haven’t looked back.”

Herdman has transformed his body since he started Mixed Martial Arts (MMA) and made his fighting debut in 2016.

He said: “I was never fat or anything but before I started martial arts I was smoking and you feel like you can’t breathe.

“You just generally feel much better in yourself. I feel happy, I can go and run ten miles.

(Daniel Quinones)

“It’s great looking good and the transformation is really cool. You don’t do it just for that, that’s like an added bonus. It’s more for your mental well-being.”

The actor said he still looks back on his time on Harry Potter fondly, adding: “It was an awesome experience, it was ten years work, I got the job when I was 13 and I learned a lot.”

Safeway Excellence Awards 2003
Joshua Herdman with co-stars Tom Felton and Jamie Waylett in 2003 (Yui Mok/PA)

He continued: “It was quite strict, the schooling was very strict, the tutoring.

“They did look after you, no complaints there, but I think it’s just a mad experience being involved in something so big so young, and having money so young, it’s kind of crazy.”

Herdman is now preparing for his second fight at Rise of Champions MMA on February 17, when he will take on Samuel Radley, and for an MMA film, called Cagefighter.

(RocEvents)

He said: “I’m excited to get back in there because it’s been since April 2016 when I had my last fight and I always said I don’t want to have just one fight, I want to have at least two or three amateur fights and see what happens.

“I’m excited to test myself. It’s generally a great experience, physically and mentally, preparing for a fight.”