(AP) -- At a north London gym on a recent evening, Claire Palmer was busy pounding her gloved fists into a punching bag.
To raise money and get fit, Palmer is trying all 30 Olympic and Paralympic sports in the next year - and boxing is on this month's schedule. Palmer, 29, is taking part in the Gold Challenge, a charity trying to get people more active by the time the 2012 Olympics roll into town.
She admits the program is a hard sell to many Londoners: Britain has the fattest population in Western Europe, with about half of all Britons overweight. Physical activity levels have largely stagnated in recent years.
"For a lot of people, it's very easy to make excuses about why you can't exercise," she said. "I think it's fantastic the Olympics are coming, but not everyone thinks that."
That's something British officials are finding out. When London was awarded the 2012 Games, the government promised it would get 2 million more people physically active by the time the Olympic torch is lit.
With fewer than 500 days to go, that looks highly unlikely.
"Based on the current figures, the target will be met sometime around 2023," said Mike Weed, director of the Centre for Sport, Physical Education and Activity Research at Canterbury Christ Church University. According to national exercise surveys, only about 127,000 more people have become more physically active since 2007.
British officials insist the goal can be reached. Sebastian Coe, chairman of the London 2012 Games, said the problem may be that they are not collecting the right kind of information to prove their goal is being met.
Last week, an independent watchdog said it may be impossible to prove if the 2012 Games improves the health of city residents. The group said there is insufficient data on the current level of Londoners' physical activity levels and called the government's efforts "a major lost opportunity."
Still, Coe said three dozen Olympic sponsors have gotten about 750,000 British children to play sports after last year's Summer Youth Olympics in Singapore.
He thinks the Olympics will motivate people to get off the couch, though acknowledged the promise to get 2 million more people active is "one of the toughest legacies to get to."
Some experts say the pledge should never have been made.
"It's naive to think that by promoting Olympic champions, people will be inspired," said Emmanuel Stamatakis, an exercise specialist at University College London. He said evidence shows watching elite athletes actually discourages most fans. "People think if they can't play football like David Beckham, why should they bother kicking a ball at all?"
There is little data to prove cities that host major sports events have higher fitness levels afterwards. After the 2002 Commonwealth Games in Manchester, officials found the numbers of people exercising actually fell.
Some experts said part of the 9.3 billion pounds ($15 billion) spent on on London's Olympic venues might have been better spent building facilities everyone could use.
"Having an Olympic running track is great for elite athletes, but if you're trying to get children involved in sport, that might not be the best approach," said Gerry McCartney, a public health expert at the Medical Research Council in Glasgow. "You could have a greater number of community swimming pools for the cost of one elite pool," he said.
"The people who get inspired to exercise by the Olympics are the ones who are already exercising," McCartney said. "They may try new sports, but they don't necessarily increase the total amount of sport they do."
Experts said without big government initiatives and drastic action, it may already be too late to get enough people moving in time to reach the 2 million target by 2012.
Faced with spiraling costs and climbing out of an economic recession that mean even the British Olympic team is running out of money, the government also axed a popular free swimming program across London last year tied to the 2012 physical activity initiative.
Dan Thompson, who founded the Gold Challenge charity, says he hopes to get 100,000 people across Britain trying Olympic sports by next year. The charity is part of the government's mass participation legacy of the 2012 Games, though only 700 people have signed up since it began in November.
At the recent boxing session organized by Gold Challenge, most of the aspiring fighters either worked for the charity or had some other connection to it.
Palmer said the Olympics was not the program's only appeal. Since she began trying Olympic sports last April, she has lost more than 40 pounds and hopes to raise at least 5,000 pounds (US$8,066) for charity.
"It's not like I think I could be Usain Bolt (the Olympic gold medallist sprinter), but I have found some sports I would like to continue," she said, citing taekwondo and fencing.
But she isn't looking forward to all of it. "I'm dreading the diving, particularly if we have to do it from 10 metres," she said. "I'm really quite worried about hitting the water from that height."
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