'Not enough strenuous activity' in school PE
There is not enough strenuous, physical activity in many of England's school PE lessons, education inspectors say.
Teachers tend to talk too much in sessions and often lack specialist training, the Ofsted report on primary and secondary PE adds.
It also highlights the fact that only a minority of schools play competitive sport at high level.
The government says its draft PE curriculum will put competitive sport back at the heart of school life.
Ofsted inspectors visited 120 primaries and 110 secondaries over a four-year period.
Overall the report said PE teaching was good or outstanding in two-thirds of the primary schools it visited, and three-quarters of the secondary schools it saw. This was an improvement on the results of its last survey in 2008, it said.
And it put much of this down to the School Sports Partnership programme, saying its impact in "maximising participation and increasing competition was clearly evident in the vast majority of schools visited".
The programme was scrapped by Education Secretary Michael Gove but partially reinstated on a dramatically reduced budget following an outcry from heads, schools and politicians.
But Ofsted warned that sustaining this level of improvement would be challenging against the "backdrop of greater expectations following last summer's London Games".
And called for a new national strategy building on the success of the School Sports Partnership Programme.
Stamina and strength
However the report found some important positive point, with most schools providing at least two hours of PE a week for pupils aged five to 14.
And only a fifth of primary schools did not ensure that all pupils could swim before they left.
However, it was concerns about the content and nature of some PE lessons than in some weaker lessons that chief inspector Sir Michael Wilshaw highlighted.
He said: "Generally, PE in our schools is in good health, but there are some issues the report highlights as areas for improvement. In particular, we found there often wasn't enough physical, strenuous activity in PE lessons.
"Some teachers talked for too long and pupils were not provided with enough activity to enable them to learn or practise their skills.
"In many of the schools visited, the more able pupils were not challenged sufficiently because teachers' expectations of them were too low.
"Schools with the best PE provision enabled pupils to achieve well by providing an ever increasing range of extra-curricular and traditional activities."
The report added: "In weaker lessons, pupils were not challenged to warm up vigorously or build stamina and strength by participating in sustained periods of physical activity.
"They were often prevented from exercising for extended periods because teachers interrupted their learning or took too long to introduce new tasks."
The report also found very few schools had adapted PE programmes to deal with the needs of overweight and obese pupils.
A Department for Education spokesman said: "We want all children to be given the opportunities they need to be fit and healthy. The draft PE curriculum published last week is designed to put competitive sport back at the heart of school life and end the damaging 'prizes for all' culture.
"We are also extending the School Games and spending £1bn on youth sport over the next five years.
"In addition we are working across government on a range of measures to improve PE and school sport as part of the Olympic and Paralympic legacy and will make an announcement in due course."
Shadow schools minister Kevin Brennan said: "As leading sports personalities have warned, under this government the Olympic legacy is at risk.
"Ministers must restore the requirement that pupils do a minimum of two hours of PE a week - the numbers of pupils doing two hours of sport has collapsed from 90% under Labour to 50% now."
But the DfE said: "The two-hour target was never a rule - it was an unenforceable aspiration that schools were free to ignore. We are freeing teachers from such unnecessary targets and paperwork which take up too much time better used in the classroom or at the running track."
Russell Hobby, general secretary of the National Association of Head Teachers, said: "Sport in schools is fit and healthy and beating its own records. Delivering two hours of PE a week in today's packed curriculum is a fantastic achievement."
Baroness Sue Campbell, chairman of the Youth Sports' Trust, said it was worrying that fewer primary schools are achieving outstanding PE than their secondary counterparts.
"From our own research we know that primary school teachers are not receiving adequate training in how to deliver an effective PE experience and this can leave teachers lacking the confidence and competence to deliver the subject effectively."
National Union of Teachers' general secretary Christine Blower said: "All the criticisms that Ofsted had of schools sports were being addressed by the Schools Sports Partnership.
"This was specialist PE teachers working across primary schools to add capacity and bring high quality, specialist, exciting teaching to children. It has been all but shut down by the coalition government."