The London 2012 Olympics must break a long trend in order to deliver a promise to leave a fitter, healthier nation after the Games, the head of an independent watchdog said on Friday.
Evidence for lasting population health benefits from previous Games or other major sporting events is scant but Shaun McCarthy, chairman of the Commission for a Sustainable London 2012, said that does not mean London 2012 will not achieve its aim.
"It's something that hasn't really happened before," he told Reuters in an interview. "London really will have to do something very special if we're going to break that cycle of seeing no effect on the grass roots participation in sport."
McCarthy's commission was set up to monitor the sustainability of the 2012 project and has voiced concern no starting points for national health status have been taken before the Games, making it likely to be more difficult to show whether any progress is made.
Sebastian Coe, a double Olympic champion and the head of the London 2012 organising committee LOCOG, promised the Games would offer more opportunities for Britons to participate in sport and set out a vision of more active communities leading to a fitter society and reduced health inequalities.
It is a bold aim and a link that has never been proven by a host city before.
"We've looked for evidence of previous Olympic Games or other major sporting events having an impact on health and sport participation and there isn't any tangible evidence," McCarthy said.
An article published in the British Medical Journal last year reviewed 54 studies conducted between 1978-2008 and found "insufficient evidence" that major multi-sport events like the Olympics benefit or harm the health of the host population.
It found that sports participation can increase, as it did around Barcelona's hosting of the 1992 Olympics. But it can also fall, as it did by two percent after Manchester staged the 2002 Commonwealth Games. [ID:nLDE64J2B8]
McCarthy said it was unfortunate London 2012 already had what his commission described as "a major lost opportunity" in not measuring a starting point for health before the Games.
However he said the monitoring of individual projects, such as a scheme called Get Set which encourages more participation in sport among school children or another aimed at getting Londoners to be more active, should be able to track whether the Games is inspiring more people to get fit.
He gave an example of a project called Inclusive and Active 2 being run by the office of London Mayor Boris Johnson.
The Mayor's research shows 50 percent of people who live in London are classed as "inactive" because they do less than 30 minutes exercise per week.
"If we can see some improvements on that figure then you could reasonably conclude there is a contribution being made to London being healthier," McCarthy said.
What he does not want is the so-called "Wimbledon effect" -- when people all over Britain dust down their tennis rackets and take to the courts for a couple of weeks only to throw their kit and their get fit plans to the back of a cupboard before the applause fades at the championships.
To avoid this short-term "festival feel" and ensure London 2012 has a galvanising effect in making people live healthier lives, McCarthy said more focus was needed on the health legacy alongside the potential economic legacy.
"I think London can do it if attention is paid to the legacy," he said. "That's a big 'if' because at the moment we're seeing lots of really good initiatives that will effectively stop when the Games finish.
"They will only deliver long-term results if there is some proper focus on legacy."