Barnsley Karate Centre is celebrating its 40th birthday this summer after welcoming thousands of students while producing 50 English and 35 British champions as well as a double medalist at the European Junior Championships who is now targeting the Olympics.

The club was established in 1978 by Ged Tumman and his then teenage son John who had been inspired five years earlier by American martial arts star Bruce Lee.John said: "My dad snuck me into the old picture house in Barnsley to watch Enter The Dragon and I was hooked. We went to classes at Dorothy Hyman and the instructor said my dad had to do it as well. We've both been doing it since.

"We've taught thousands upon thousands of kids. Every time I am in Barnsey town centre, someone shouts to me: 'heyup sensei'. Now I am getting the grandchildren of children I used to teach when we first started.

"My dad is 80 now and he's had two new knees but he still comes down a couple of times a month to train. He's wound down his involvement in the club but he still turns up and points out all the things he thinks I'm doing wrong then goes home.

"My mum Pat has been doing all the books and taking the subs for the last 40 years. All the students know her as 'Auntie Pat'. She's the real backbone of the club. We've had a great time running the club together and we have a lot of good memories."

The club was founded across the road from Ged and Pat's house, at the now demolished Kingstone Parish Hall. Ged and John were both miners at Grimethorpe and Redbrook pits respectively but left their jobs after the 1985 strike and ran their karate coaching business full-time. They then bought the club's current base on Regent Street South in Barnsley town centre.

"We had been looking for ages for a base then we dropped on with this place in town. We pretty much knocked it all down and rebuilt it. We ran it as a gym until the year 2000 then focused on karate full-time."

John won the England under 16s schoolboy title aged 12 then, as an adult, competed across Europe and took bronze at the English Championships in 1987. He suffered a serious knee injury in 1995 but still won the English Masters title twice. Several of his students have surpassed his career by competing at European and world level including Lauren Fretwell, a 17-year-old from Dodworth who has won two bronzes at the European Junior Championships. She is working towards the 2020 Tokyo Olympics when karate will be included for the first time.

John said: "Tokyo might be a little bit too soon but she will be at her peak for the 2024 Olympics. She is faster than most of her rivals now but she needs to get stronger and more experienced. She's a fantastic prospect, a very hard-worker and I believe she could be our club's first Olympian."

John estimates that more than 350 students have claimed black belts at the club while they have organised nearly 100 karate competitions as well as 29 training camps in Spain, Germany and the UK. They have also raised £64,000 for local charities with fund-raising walks from John o' Groats to Lands End and across Hadrian's Wall.John and Ged – who was an England referee – once demolished a barn with their hands and feet in Bradford, which made the local news. They also ran self defence classes for schoolgirls.

John, who is now 55, is determined to carry the club on for at least another decade. He said: "We've got to 40 now and I want to get to 50. Then it might be time to hang up my suit. I would like to pass the club on to someone. My granddaughter Morgan is 14 now and she could be next in line if she wants it."

Asked why he loves the sport, John said: "It's such a good lifestyle. It keeps you fit and teaches you about respect and discipline. It's got everything you need to be a good person."