Ofsted says state pupils denied competitive sport
State sector head teachers need to stop treating competitive sport as an "optional extra", says Ofsted's chief inspector Sir Michael Wilshaw.
In a report, commissioned after the 2012 Olympics, he argues too many top athletes are from private schools.
Schools where pupils lack opportunities to excel in sport also tend to do worse academically, according to the report.
But the National Union of Teachers said Ofsted's comparison between state and private school sport was "ridiculous".
The report, Going the extra mile: Excellence in competitive school sport, was commissioned after the London games to explore why so many Team GB athletes had been educated in private rather than state schools.'Not good enough'
It found "unacceptable discrepancies" where fewer than one in 10 pupils in England attends fee-paying schools but privately educated athletes make up the majority of players in rugby union's English Premiership and more than a third in top-level cricket.
Sir Michael told BBC Radio 4's Today programme: "A third of our youngsters who excel in sport across different disciplines come from the independent sector.
"If you strip away football, it's more like 50%, particularly in national sports like rugby, cricket and swimming.
"We're saying it's really not good enough."
Ofsted visited 10 independent schools, 35 state schools and surveyed more than 500 head teachers and more than 1,000 11 to 18-year-olds.
The majority of state school heads said competitive sport was optional. Only 13% said they expected all students to take part.
The report finds that in the most successful schools, both state and private, heads recognise that competitive sport can help build an ethos and boost grades.
Strong teams rely on teachers prepared to dedicate time and energy before, during and after school, as well as at weekends, say the authors.
Staff needed to be able to identify talented pupils for extra coaching and ensure matches were accessible to everyone else, they added.
The report found 15 of the state schools visited were "delivering excellence" in competitive sport.
"They demonstrate that high school fees and large playing fields are not a pre-requisite to success," said Sir Michael Wilshaw.A state school success
Mo Farah's former PE teacher Alan Watkinson is in no doubt as to the importance of school sport.
"We can see the difference it makes, not just to them in terms of their sporting ability, but also as human beings," he said.
Mr Watkinson, who taught the double Olympic champion at Feltham Community College, said Farah was unable to speak English as a Year Seven pupil.
"It was recognised that sport was really a way to bring him on," he told BBC News. "We didn't necessarily think he would become an Olympic champion, but it was part of his whole development.
"Every child should have the right to be in a position where they could become a sporting hero."'Worrying inconsistency'
Sir Michael said: "It is clear that a commitment to sporting excellence often reflects a culture of high expectations and achievement in the school as a whole.
"Schools that win on the field win in the exam hall."
Youth Sport Trust chief executive John Steele said: "The findings from this report highlight a worrying inconsistency in the provision of competitive sport being offered in state schools.
"It is encouraging, however, to see that where state schools take competitive sport seriously, there is a clear correlation to academic attainment."
But Geoff Barton, head of state comprehensive King Edward VI School in Bury St Edmunds, Suffolk, told the BBC he did not welcome Sir Michael's "pontificating".
Speaking to the Today programme, he said: "For me the most infuriating part of it is that there are parents round here who may be making a decision about whether to send their child to a state school like ours, or an independent school, who will hear his stereotyping of the state sector and decide they are then going to move into the independent sector."
NUT deputy general secretary Kevin Courtney said: "State schools have neither the same facilities nor time and space in the curriculum for sport as independent schools.
Mr Courtney said the government was allowing free schools to open sometimes with "no playgrounds let alone playing fields", had abandoned the target of two hours PE a week and had withdrawn funding for the Schools Sport Partnership linking schools with local sports clubs.
"Teachers already put in the 'extra mile' for students, often working up to 60 hours a week, many take on extra-curricular activities.
"It is not teachers who are the barrier to a good sports education in schools but a lack of support, resources, funding and facilities. Those are the areas Ofsted should have been looking into with this report."
The Department for Education said it was giving primary schools in England more than £150m year to boost sport and PE, amounting to £9,250 for a typical school, enough for a specialist PE teacher one day a week.
"Too few children have been taking part in competitive sport in recent years. That is why we are strengthening competitive sport in the new curriculum at all key stages so that all pupils learn to compete against their peers.
"The new curriculum also encourages pupils to build strong links to community sport outside of school hours," said a spokeswoman.