Tennis and football have been warned that part of their public funding is at risk after both sports suffered big drops in participation in England.
Sport England, which distributes Lottery money at grassroots level, says tennis has failed to capitalise on Andy Murray's Wimbledon win in July.
Football is now fourth behind athletics and cycling in terms of participation, with swimming the most popular.
A total of 15.426m people play sport each week, up 206,000 from April.
Sport England claim the figures mean the original boost from the London 2012 Olympics has been maintained.
However, the numbers of people participating in sport is actually down 50,600 on the 15,512,500 from this time last year.
Sport England intends to hold meetings with both the Lawn Tennis Association (LTA) and Football Association (FA) before deciding in January whether up to 20% of their funding will be suspended.
Tennis, which earlier this year had a £530,000 funding cut imposed, could lose more of its £17.4m four-year award after participation fell from 423,400 in April to 406,000.
Football's participation numbers are down to 1.83m, a drop of 100,000 since April. Its 2013-17 funding award was £30m.
"We are very disappointed by football's results and the FA really need to grasp this," said Sport England chief executive Jennie Price.
"There is now to be a discussion with the FA and our board, but we operate a payment for results scheme so football are definitely in the at-risk zone."
FA general secretary Alex Horne said his organisation had to work to do.
"Understanding and reversing the fall in participation is an immediate and top priority," he said.
"We are working exhaustively with Sport England and our other partners to ensure the right plans and programmes are in place to achieve this."
Price said the tennis results were also disappointing but felt the LTA was at least attempting to address the issue.
"They did a lot in August and September and had a bit of a lift from that but it was not sustained," she said.
"They need a really good delivery system outside the clubs, such as on the park courts, and they will be getting that message very loud and clear from us.
"I should say they started to engage in the participation agenda and are genuinely focused on it now. We couldn't have said that in the past."
Phil Smith, director of sport for Sport England, added: "I think we've probably finally dispelled the myth that a British guy winning Wimbledon would do something to increase participation figures.
"It's not that simple to translate into a weekly habit of ordinary people playing a sport. It takes more than just a Wimbledon winner."
Nick Humby, the LTA's chief operating officer, said: "We are hugely disappointed that the October 2012/13 numbers have gone down, but we take encouragement from the peak between July and September exceeding that of the Olympic and Paralympics last year.
"That was partly due to Andy Murray, partly to the extraordinary weather, and partly to the stuff we are now doing out and about around Britain."
Humby said there were signs of encouragement with the number of people playing monthly holding up, as has the number of women and young people aged under 16 playing the sport.
The LTA will also have a new chief executive, Mike Downey who is coming from Canadian tennis, starting in January.
Sport England's figures, which are compiled twice a year, in April and October, focus on the number of people aged 16 and over playing at least 30 minutes of sport at moderate intensity at least once a week.
The Active People Survey shows:
- The number of disabled people now playing sport each week has increased by 62,000 to a record high of 1.67m.
- The number of people of BME (black and minority ethnic) origin playing sport regularly has jumped from 2.13m to 2.7m.
- A record number of people aged 26 and over are involved in sport.
- Swimming remains England's biggest participation sport with more than 2.9m people going for a swim at least once a week.
- Athletics and cycling, in second and third place in the table, each boast more than 2m weekly participants.
However, the picture is not entirely positive, with the report also showing:
- The number of 16-to-25 year olds in sport has declined to 3.74m.
- Only five sports have increased participation overall since 2005: athletics, cycling, boxing, table tennis and archery.
- Sixteen sports have seen a decline over that eight years, including swimming, football, golf, tennis and cricket.
- The numbers participating in tennis has fallen by 39,000 from this point last year despite Andy Murray becoming Britain's first Wimbledon's men's singles champion since 1936.
- Football has dropped from being the nation's second biggest sport in terms of participation to the fourth overall with 1.8m players.
Pete Ackerley, the FA's national game senior development manager, told BBC Radio 5 live: "We have been asking our players how they want to consume their football.
"What we are finding now is that there are different ways of playing football - they want to play at different times, in different formats, they want to play shorter versions.
"I guess it's the society we are in; they want instant football. They don't want to play as often, and the [Sport England] measurement is four times per month, so that is playing every week.
"What we're finding is that people have got very busy work lives, they have got very busy family lives, and they are fitting in their sport participation differently - and team sports, and in particular football, has been impacted by that."
Price added: "We are concerned about the results for young people. Although the majority of 16-25 year olds still play sport regularly, the numbers are not going up.
"The evidence shows a sharp drop in the popularity of traditional sports, like football and netball, and we need to make sure they have a wider range of sporting activities to choose from."
This time last year, Sport England granted most sports funding for the next four years, but six sports - swimming, tennis, basketball, squash, table tennis and fencing - only received a one-year allocation.
They were essentially put on probation and given 12 months to meet specific targets, such as raising levels of participation.
Sport England will make its future funding decisions on these six sports in January, when it will also make a decision as to whether up to 20% of football's funding will be suspended.
The feel-good factor from Britain's cycling successes at London 2012, coupled with Sir Bradley Wiggins and Chris Froome winning successive Tour de France titles, has helped make it the stand-out performer, increasing participation by 137,000 from April to October 2013.
"I am encouraged that sports participation is back up on the rise compared to six months ago and that participation among disabled people is at an all-time high," said Helen Grant, Minister for Sport.
"More women are getting involved, too, and I want to keep up that momentum.
"But there is still more to be done to encourage greater participation across the board. Sports governing bodies must step up and deliver for the half a billion pounds of public money that they receive.
"If they don't, funding will be taken away and channelled into grassroots sport through other routes."
Clive Efford, Labour's Shadow Minister for Sport, added: "In the year following the 2012 Olympic and Paralympic Games, figures show that overall participation is down. The most damning figure is the reduction in participation among 16-to-25-year-olds by 51,000."
He claimed Prime Minister David Cameron had "no strategic plan for sport" and had "failed to capitalise on the explosion of enthusiasm" generated by the Olympics and Paralympics.
"A golden opportunity is being squandered," added Efford.