The visitors from Ajax's celebrated youth development programme were adamant. "If you tried to copy us, you've got it wrong," they told Nick Cox, the co-ordinator of Watford's academy. Then came the pay-off. "You've managed to get even more coaching time with the kids than we have. Well done!"

In the debate as to how England can produce more, and better, footballers – an issue raised yet again after the feats of Germany and Spain at the World Cup – Watford are providing a persuasive answer. Their academy for 11- to 16-year-olds at Harefield, just off the M25, has attracted admirers from as far afield as Valencia as well as a slew of Premier League clubs.

Since the Premier League began introducing academies 12 years ago, the problem clubs have most consistently complained about is how little time they can spend with young players. Watford used to have similar gripes. Cox says: "The kids would be tired after a day in school, then dash home, maybe grab some fast food on the way, then travel to the academy to do an hour of training, then travel back again and then maybe stay up late to do their homework. They may not have been eating right, probably weren't getting as much rest as they should have and, on top of that, weren't playing as much football as children in European countries with different education systems."

Proponents of youth development invoke the so-called 10,000-hour rule, according to which people who achieve excellence in any sphere only do so after about 10,000 hours of practice. Ged Roddy, the Premier League's director of youth, says: "Academy players will need up to 20 hours a week of contact time with their coaches across the secondary school years if they are to have any chance of meeting this level of contact."

No Premier League club is near that target even though most go to considerable efforts to strike deals with schools over the release of players. Sunderland, for example, employ Brian Buddle, a former head teacher, to oversee maths and English tuition for teenagers when they are given a day off school to train and have been awarded Grade 1 approval by Ofsted.

Watford have gone even further. Cox says: "Like all clubs we wanted to increase the contact time with the kids but we decided to go about it in the opposite way to most: not to get them out of school, but to put them into one."

Three years ago, they offered 34 young players places in the local secondary school in Harefield, which, driven by the former Olympic figure skater Haig Oundjian, a governor at the school and at the time a director of Watford, was being reinvented as a comprehensive academy with a focus on sport. So unlike Dutch clubs or residential programmes for young footballers such as France's acclaimed Clairefontaine model, Watford have integrated their academy players into a mainstream school, securing more time with their charges while saving on cost and preserving a healthy sense of normality among aspiring footballers.

Cox says: "We pick the children up at around 7am and they then do all the normal subjects but also have scheduled coaching throughout the day – at times when they are fresh – then we drop them home at 7pm. We get to do about 15 hours of football with them a week, up to three times more than most other clubs in this country.

"And not only do kids not have to sacrifice their education, we find that they actually perform better in the classroom as well as on the pitch because the environment is more stimulating and they are more driven in everything – they know if they are not doing their best in the classroom we can take away the privilege of training. We have 50 kids here now – before, they might have been in 50 different schools and we would have had no idea what they were doing for 95% of their time. Here we can take more responsibility for their development, both as players and as people."

The Premier League approves. Roddy says: "The development of academies and the deregulation of schools may provide some interesting opportunities for football to link with the education system. This could provide a more flexible environment in which to negotiate the much-needed access to coaching for the potential elites that frequent our academies."

Cross-training is another development buzzword. Aston Villa, West Bromwich Albion and Birmingham City have started to put this into practice in a limited sense – by training their 10- to 14-year-olds together, exposing the children to a wider range of playing and coaching talent.

Again Watford go further. The scholars at Harefield also include gifted young gymnasts, dancers, cricketers and even a jockey and an ice hockey player, and Watford take advantage. Limbering up every day with the ballet teacher has proved an enlightening experience. "We were a bit sceptical at first but it has really helped our strength and flexibility," says the 15-year-old Richard Mensah. "You notice it most when you stretch for the ball – you can stretch farther without feeling any strain."

Already Watford are reaping the fruit. They reached the quarter-finals of the FA Youth Cup – the national tournament for Under-18s – in each of the past two seasons. "Last season we beat Liverpool at Anfield before losing to Chelsea," Cox says. "That was a massive marker for us because our players all grew up on average 12 miles from Vicarage Road whereas many of the Premier League clubs start bringing in players from all over Europe once you reach over-16 level, so it's been a great indicator of the progress we've been making." On the final day of last season, the 17-year-old Gavin Massey laid down another marker when he became the first Harefield graduate to make his debut for the senior side, appearing as a substitute against Coventry City. He has since signed a professional contract. More, it is hoped, will come.