The earlier youngsters are turned on to sport the greater the chance Britain will have more champions, says Sir Clive Woodward.
Sir Clive, the rugby World Cup winning coach, said Britain's sportsmen and women often achieved more through luck than by design because the right programmes to promote success were not in place in schools.
"The earlier youngsters can be involved, the better, because even if they don't make it, they won't have done themselves any harm. It will have made them a better person, better able to enjoy the work they do because they feel good about themselves," he said.
He also believes that role models such as Jonny Wilkinson and David Beckham can inspire young people.
"You hear these stories of David Beckham carrying a football round wherever he went and that is what you need: that passion and that skill-set for what you do," he said.
"If people such as Beckham and Wilkinson can attract kids to sport because of how they look and the way they dress, that's fine, I have always said that in rugby union we need to produce individual role models and superstars."
Sir Clive, 48, backing The TES's Get Active campaign, said parents should provide the first good examples of a healthy lifestyle.
He said: "We all enjoy eating crisps or going to a McDonald's now and again. As with everything, it is about moderation, but I do believe that parents can encourage their children to take up sport."
He admits that it is more difficult for today's young people than it was for him. When he was young he was able to jump on his bicycle for a ride with his mates or run to the park to play football or cricket. Today, because of parental concerns about safety, children are more often transported to organised sport rather than being left to organise their own ad hoc games.
Sir Clive studied at Loughborough college before the start of a playing career, as an amateur. He earned 21 rugby caps for England and a place on two British Isles tours in 1980 and 1983.
He says that the satisfaction of England winning the William Webb Ellis Cup was almost eclipsed by his satisfaction at the fact that England arrived at last year's World Cup as favourites, and then proceeded to justify that position.
His main message for would-be sports stars who dream of being the next Jonny Wilkinson is that there are no short cuts. "I try to get across to kids that it is the work ethic that underpins what we have done." Schools, he believes, can tap into modern methods of training. "The things that we have done with England, and players like Martin Johnson and Jonny Wilkinson agree, can be done by kids. Weight training is so important, not heavy weights but the sort of hand-held weights which you can easily keep at home. This builds up a huge level of fitness.
"The ingredients of what we were doing as an England squad over the last two or three years can be applied to a group of youngsters. If you have an outstanding kid, you try to give him or her a development programme but you also say there are no short cuts.
"It doesn't matter that rugby is a team sport, as we are no different to an athletics team with all its individual and different disciplines.
"We play together as a team but individually, they all had to prepare themselves, they all developed the same mind-set and that's why we won," said Sir Clive.