"In those days there were no women and children doing martial arts and it was taught in a very militaristic way," said Johnson, who teaches Tang Soo Do, a Korean varient of karate.

"My first tutor said not to bother, as long as I had two legs I'd be no good at karate. If you weren't tough enough you fell by the wayside."

However, Johnson persevered and, after taking over the running of the club when his instructor returned to Korea, has seen Master Johnson's Family Karate expand at such a rate that it now boasts more than 3,000 members of all ages at 15 clubs around the Midlands and Yorkshire.

A 6th degree black belt, Johnson teaches at three of the clubs - Coventry, Leamington and Pershore - and is supported by his wife Rachel, who is also an instructor.

Their sons are also following in their parents' footsteps with six-year-old Owen holding a brown belt and Arthur, three, having recently taken his yellow belt.

"It's a great life," said Johnson, who gave up working at British Rail to become a full-time karate instructor.

"I'm fortunate to be doing something I love. It has enabled me to travel all over the world, finding the best techniques and ways of teaching.

"Many people I have taught have decided they want to teach, too, and I still do all the belt tests and seminars for all the clubs. Seeing my name on uniforms is an honour and gives me a sense of accomplishment."

Despite being 58, Johnson is not ready to hang up his uniform, or Do Balk, just yet, pointing to the high rate of life expectancy on the Japanese island of Okinawa, the birthplace of karate.

"I'm certainly a lot more supple now than when I was in my 30s and can still kick over my head.

"In this country by the age of 35 most people are ready for the knacker's yard and down at the pub for a pint. Yet in Okinawa it has the highest incidence of longevity in the world and that it is the birthplace of karate is a factor - the more physically flexible you are the more mentally flexible you'll be.

"I'm not expecting to give up any time soon and I expect to be training into my 80s and 90s."

Johnson believes that when looking for an instructor you should go for the one with the most experience "for they can make you great".

However, he still has not forgotten his first leaden-legged steps into the world of karate.

"I still remember vividly what it was like to be a beginner," he said.

"But the good thing is that you can feel the benefits within a month, while gaining fulfilment and being happy and that's all anyone can ask for."

For more information about Master Johnson's Family Karate, log on to www.johnsonskarate.comindex.jsp