The idea of free swimming for all before the London Olympics is a compelling one but feels like it was drawn up on the back of a cereal packet. Indeed it was – by Kellogg’s, two months ago.

It is running a promotion until July with tokens on 30 million boxes that can be exchanged for a free swim at more than 500 pools.

So what’s new in the Government’s £130 million plan to open up 1,600 local authority pools to the over-60s from April next year and the rest of the nation beyond that? The answer is not a lot, but it makes for a catchy headline on an otherwise uninspiring tale about the sporting legacy of the 2012 Olympics.

Ministers have had three years to come up with a clear vision of how 16 days of elite competition will change the way Britain takes part in sport.

While going in the right direction, their legacy masterplan still fails to answer the key questions. Just how will watching Paula Radcliffe (hopefully) winning the marathon in 2012 inspire a legion of long-distance runners? And who will pay for the facilities and the coaching to make sure those who do show an interest can be catered for?

It is true that swimming is an easier sport to sell than running because it seems less like exercise to most of us.

But at a time when the Government is losing the battle against childhood obesity and the fall-off in participation after school is increasing, getting more pensioners enthused by breaststroke may just be a case of stemming the tide by topping up declining participation levels.

Meanwhile, Olympic chiefs worry privately that the window of opportunity to inspire the next generation of sports nuts may be closing rapidly.