Kevin, 34, retired from full-time teaching last year as head of physical education at Lea Valley High School in north London. Since then he has developed a set of DVDs called Inclass Fitness (www.inclassfitness.com), which gets primary pupils learning and exercising at the same time. So far, it is a hit, with 32 schools in the Enfield area using it, but that is not enough. Following in Jamie Oliver's footstep, Mr Matthews is looking for a school revolution.
Is this yet another keep-fit video?
"I wanted to help pupils do 20 minutes of PE a day. I thought about primary schools, fitness levels, education and kids, and putting them all together. When I was head of PE I began helping people with weight issues and low self-esteem. I created a club and 75 students joined. I thought there must be something here, but didn't feel I was reaching enough people so took the gamble and went part-time."
What inspired you?
"I was sent by Enfield Council to Canada to look at its PE system. Although students are kept active, they aren't necessarily occupied. I thought, if you're in a classroom getting kids active, why not teach at the same time?"
Who made the biggest impression on you?
"One teacher was really small and the most energetic person I have come across. She had a head microphone on and had the whole school exercising in a confined space. Imagine if you could get all teachers to be like her..."
What else are you working on?
"Times tables in our schools aren't good enough. My friend, an A-level maths tutor, says the first thing he has to do with his sixth-formers is a multiplication recap. With the DVD, the children memorise their times tables to movement, music and rhyme."
Does it work?
"With secondary pupils you can leave them to their own devices but if you want to change a pupil's attitude to eating, exercise and health, you have got to do it when they are young. Primary schools are a good place to do this."
Is obesity a big deal, then?
"Definitely, we don't tackle it hard enough. Children should be weighed in Year 5, not Year 6, so we can do something about it. It's not all to do with movement, it's also about what they are putting in their mouth. I have thought about speaking to Jamie Oliver, because what I am doing complements what he does. I want to be influencing schools around the country, and I want parents involved."