The number of pupils in all-girls' schools participating in at least two hours of PE and school sport a week is a quarter less than the national average. The government figures will add to concerns that teenage girls are reluctant to take part in healthy physical activity because it is not seen as "cool".
They were revealed in a response to a parliamentary question by Kevin Brennan, the children's minister, who said that in 2006-07 only 65 per cent of girls' school pupils had two hours of "high quality" PE and sport, compared with 86 per cent nationally.
Two hours of PE and sport each week is the amount the Government says all 5 to 16-year-olds should have access to both inside and outside the curriculum. So girls not benefiting may still be attending PE lessons. It could be that they are just reluctant to take part in sport after school.
Clarissa Williams, head of Tolworth Girls' School in Surbiton, Surrey, said that there "does seem to be a resistance on the part of young women to participate in PE".
Ms Williams, who is also vice-president of the National Association of Head Teachers, said: "It has been part of the traditional culture that boys tend to have been more keen on physical activity anyway. By the time they get to Year 9, girls are sitting down and being much more sedate."
Don Foster, the Liberal Democrat spokesman for culture, media and sport, who asked Mr Brennan the question in Parliament, sees it as part of a wider problem: women's participation in moderate-intensity sport is falling but among the population as a whole it rose.
"The Government must recognise the gender-based disparity in sports participation in our education system has still not been properly addressed," he said. "We need much greater support for the types of physical activity girls are interested in, such as dance."
Margaret Talbot, chief executive of the Association for Physical Education, suggested the differences between participation for girls and boys was to do with the gender of teachers available to supervise after- school sport.
"I suspect PE teachers in all-boys' schools will get more support from their male colleagues for running a whole range of sports than female PE teachers do from their female colleagues," she said. "I think that is partly because of women's family responsibilities. Girls tend to be much more conscientious about their exam work and drop out-of-school sport and other activities outside the home earlier.
"Girls also generally have less freedom outside the home."
Professor Talbot suggested schools could help by providing chaperones to ensure pupils got home safely.
Dame Kelly Holmes, the double Olympic gold medal athlete who has been appointed the Government's national school sports champion, has argued that the traditional "uncool" PE kit is putting girls off. She believes girls would continue playing sport into their teens if they could wear fashionable hoodies and tracksuit bottoms.
WE LIKE YOGA, DANCE, GYM AND KEEP FIT
Extra netball is not the way to get girls interested in sport, according to Clarissa Williams, head of Tolworth Girls' School in Surrey.
Ms Williams said the fall-off in PE participation used to begin at her school once girls reached 14. "They would turn up without their kit or say `I don't want to do it'," she said. "We have had to write to parents saying it's a statutory requirement."
Around a year ago her PE department decided to counter the problem by giving pupils more choice in a wider range of activities that were not necessarily team sports.
"More netball is not the answer," she said. "We found our girls respond much better to yoga, badminton, gymnastics, dance or keep fit."
It has already resulted in a noticeable improvement in attitude towards PE among Year 10 and improved participation in team sports.
"The message is it is cool to participate," she said.