Millions of children are putting their future health at risk by refusing to exercise, new research reveals. Three out of four take part in little or no physical activity, many hate school sport and large numbers, especially girls, have negative attitudes towards exercise, according to the unpublished survey.

The findings will concern Ministers, who are trying to increase the low levels of activity among Britain's pupils to combat growing childhood obesity.

Officials at Sport England, the government-funded sports council which undertook the study, were shocked to find that only one in four five- to 16-year-olds in England plays sport regularly. They warn that pupils who do not embrace sport may develop health problems in later life with an increased risk of heart disease and strokes.

Sports stars such as England rugby captain Martin Johnson and cricket skipper Michael Vaughan have thrown their weight behind The Observer 's efforts to persuade Ministers to revive school sport through our Fit For The Future campaign.

The researchers identified four groups of pupils:

Reluctant participants: 24 per cent of pupils.
They include 'couch potatoes, who dislike sport intensely, have a low level of participation and lead a sedentary lifestyle', and 'tolerators, who have an average level of participation but do not enjoy it much'. They are usually primary school girls and older boys. 'They may already be lost to sport and consequently have the highest risk of poor health associated with inactivity in late life.'

Unadventurous: 14 per cent.
They play little sport and dislike it, but not as much as 'reluctant participants'. They are mainly secondary pupils, especially girls aged 11-14. This includes many children from ethnic minorities.

Untapped potential: 37 per cent.
These are 'not averse to sport but spend relatively small proportions of their time actually taking part in it.' They are mainly younger people, especially girls.

Sporty types: 25 per cent.
They play sport regularly inside and outside school, and enjoy it. Two-thirds are boys.

Leading paediatrician Dr Peter Sullivan, who is also an expert in children's nutrition, said the findings were alarming. 'We have all these sugary, fatty foods which are increasing the energy intake, but our kids' energy expenditure is not going up in proportion. What Britain needs is a cultural change in its attitude towards fitness.'

The research suggests that government efforts to get 70 per cent of the population doing five lots of at least half an hour's exercise a week by 2020 are doomed to fail. It predicts the numbers in every age group from six to 44 taking part in sport will fall from 53 per cent in 1996 to just 46 per cent in 2026.

Long working hours and parental fear of letting children play outside are also driving participation rates down, warns the report, and spending billions in Lottery money on new sports facilities has not led to more people taking exercise. Drastic action is needed to reverse these trends. The report says: 'Public policy interventions in sport will 'need to go where we have never been before'.

A spokesman for Education Secretary Charles Clarke said: 'This research shows the scale of the challenge in trying to encourage schoolchildren to do more sport. We have got to make sport more attractive to them so that it becomes part of their daily lives.'

The National Union of Teachers is also backing our campaign. 'It doesn't help teachers to have bored kids who haven't got rid of their excess energies,' said general secretary Doug McAvoy, a former PE teacher. He endorsed our call for extra funding so schools can hire coaches and fitness instructors.

Stars back observer campaign for school sport

Michael Vaughan
England cricket captain

'I'm fully behind the idea of getting schools to devote more time to sport and there are plenty of good ideas here [proposed by The Observer ] which should be looked at by the Government. I feel much more could be done to improve the coaching and facilities available to schools. What I would really like is one morning or afternoon set aside each week for sport.'

Dr Peter Sullivan
Leading paediatrician and expert on nutrition in children

'Our schools are bottom of the league table when it comes to the amount of time given to PE and sport. A lot of children would rather sit at a screen and play Championship Manager than go outside and kick a football. That matters because we have seen the numbers of overweight children double in the last 10 years. People need to realise that the habits set in young years will determine your adulthood unless there's big social change.'

Martin Johnson
England rugby captain

'It's a shame how sport seems to have taken a back seat at school. The decline needs to be reversed. When I began playing rugby as a kid in Market Harborough, I was very fortunate to have dedicated teachers who put in a lot of time and effort, in and out of school hours. But it's not just about kids who are good at sport. It's just as important that young people who may not have much ability but get a hell of a lot out of sport have a full PE curriculum.'

Tam Fry
Honorary chairman of the Child Growth Foundation

'Sport in school is extremely important, but so is identifying the children who are most at risk. We feel every pupil should be given a yearly body mass index test. This data would identify children who were managing to overcome obesity as well as those becoming unhealthy. We could extend the checks down to nursery school level to identify which play initiatives help toddlers stop getting fat in the first place.'

Linford Christie
100m gold medal winner at the 1992 Olympics

'Whatever happened to sport being fun? When I was at school you wanted to represent your school in a sport and the teachers put a lot of time and effort into these sessions. The Government needs to reverse the trend set by the Tories of selling off playing fields and make sport a crucial part of the national curriculum.'

Jade Johnson
Commonwealth Games and European Championships silver medallist in the long jump

'When I was at school we only did one PE lesson a week. I think every pupil needs to get PE at least twice a week. And we need better facilities. Sports stars both current and retired could help by going into schools' PE lessons and having a chat and showing the pupils a few bits and pieces.'

Michael Spens
Headmaster of Fettes College in Edinburgh, Tony Blair's old school, where every pupil receives three hours of PE a week

'The curriculum works more effectively when students have regular exercise and blood is getting to the brain. We believe in the importance of PE. Here it's taught as part of the curriculum and, being a boarding school, there are a lot of extra-curricular activities. A healthy body makes for a healthy mind. We would support a reversal of the trend of selling off school playing fields and facilities.'