Ofsted said the 2012 Olympics posed challenges

Ofsted found that increased link-ups with sporting clubs meant greater out-of-hours activity, while most children did two hours of PE a week.

However, some teachers had a "lack of understanding" of what skills and fitness pupils were expected to show.

Ofsted inspected 22 schools and 117 PE lessons and activity sessions.

Club links

Its report looks at the government's Physical Education, School Sport and Club Links strategy, which aims to get 85% of pupils doing at least two hours of exercise a week by 2008.

Links with clubs, such as football, basketball and netball teams, were good for almost half of the schools Ofsted inspected.

The pupils must be getting fitter with the amount of extra PE they are doing Jo Andrews, sports teacher What are schools doing for PE?

This made a "positive difference", allowing "more time and attention" for exercise.

Chief inspector of schools David Bell said the government's programme had delivered "improvements".

"The strategy has yet to reach all schools. The challenge ahead is to ensure that the benefits felt by these schools are extended to all schools and all pupils," he said.

Exam disruption

"With the Olympics in our sights, now is a great time to give all our pupils the best sporting chances."

But the report said exams "considerably reduced" secondary pupils' access to indoor spaces, such as gyms and halls.

Other findings included:

• PE teaching was "generally good" but the "proportion of very good teaching remains disappointingly low"

• Assessment of pupils' performance was "often weak" because of a "lack of understanding"

• Provision for children who were "gifted and talented" was found to be "no better than satisfactory" in almost a third of the lessons viewed

• Primary school pupils were "overwhelmingly positive" in their attitude to sport, but in one in 10 secondary lessons attitudes and behaviour were "unsatisfactory".

A Department for Education and Skills spokesman said: "It takes time for all schools to reap the benefits of being in a school sport partnership.

"We expect the picture to further improve as schools reap the full benefits of the strategy."

Schools minister Lord Adonis added: "Many of our 2012 Olympic medal winners are at school today.