Teachers are weary of trying to squeeze PE lessons in between literacy and numeracy hours, and parents are tired of being blamed for the school run and for raising a generation of couch potatoes. Both struggle against pressures not of their making: the testing culture, computer games, junk telly and junk food. But, despite this tough competition, some schools are winning the fitness race, finding sophisticated and imaginative ways to exercise children’s bodies as well as their minds.

The new battle of the bulge

We are living with “an epidemic of obesity”, says Professor Neil Armstrong, director of Exeter University’s children’s health and exercise research centre. The number of obese adults in the UK has tripled in the past 20 years and, according to the international obesity task force, Britain is “showing probably the fastest deterioration of anywhere in the world”. Andrew Prentice, professor of international nutrition at the London School of Hygiene and Tropical Medicine, says the lives of seriously obese children are being cut short by up to nine years and some may die before their parents.

Research carried out last year at King’s College, London, revealed that the proportion of overweight children almost doubled between the mid-Eighties and mid-Nineties. In 1984, 5 per cent of English boys were overweight; by 1994 the figure was 9 per cent. Girls’ weight increased by a similar amount. Other research paints an even bleaker picture. Leeds paediatrician Mary Rudolph found last year that 22 per cent of all seven to 11-year-olds were overweight, and 11 per cent of girls and 12 per cent of boys were obese. Obesity in adults can be defined roughly as being 20-25 per cent over the “ideal” weight for height. A more precise definition is reached using the BMI, or body mass index (weight in kilos divided by height in metres squared). An individual with a BMI of 27 is overweight, while 30 is considered obese.

For children, obesity is more difficult to define because their BMI changes naturally as they grow. Babies, for example, can be chubby and healthy. Recent work by the Institute of Child Health has helped develop internationally accepted definitions of child obesity, with the aim of pinpointing young people at risk of becoming obese adults. The problem can start depressingly early. In 1989, 14.7 per cent of children under four were overweight. By 1998, this figure had soared to 23.6 per cent, according to analysis of data on 50,000 infants carried out by Liverpool University.

Couch potatoes?

Children are getting fatter,but not because they are eating more. Despite the prevalence of junk food, their calorific intake is lower than it was pre-1960. They are simply less active.

But the “couch potato” stereotype of the adolescent who slouches between television and computer is simplistic. Information on how children occupied themselves 30 to 40 years ago is skimpy, but the image of an idyllic childhood spent roaming the fields or kicking a football in the street is probably exaggerated, says Stuart Biddle, professor of exercise and sport psychology at Loughborough University. Children then also spent a lot of time sitting still - reading comics or doing jigsaws. While there is a serious problem, we must be cautious of the “moral panic” surrounding children’s lifestyles, he says.

Professor Biddle warns that using a single activity such as TV-watching as a marker for child fitness is dangerous. In a recent review of all adolescent studies that measured physical activity and TV and computer use, he found “virtually no relationship”. In other words, some children can be highly sedentary and very active - a pattern, he points out, adopted by many top athletes. Young people agree with him. In a survey last year carried out for Children’s BBC, youngsters proudly proclaimed their skills on the internet - and at football and swimming.

The active child

Experts talk of “active” rather than fit children. Fitness in terms of ability to reach certain levels of performance is not the key issue. “If you get the activity right, the fitness will follow,” says Professor Armstrong. Activity is a behaviour a child can control, whereas about 40-60 per cent of “fitness” is genetically determined. In other words, you can’t make a racehorse out of a carthorse - and it is counterproductive to try - but you can aim to have an active carthorse.

Children should be active for at least 30 minutes, and preferably 60 minutes, every day, according to well-established guidelines. This does not mean a vigorous game of rugby every afternoon. A brisk walk is enough. But to see improvements in fitness, children, like adults, probably need more intense exercise - maybe three 20-minute sessions a week with their heart rate at 80 per cent of maximum.

Motivation

The adage “healthy bodies, healthy minds” is true. Researchers talk of the psycho-social benefits of exercise, and schools that encourage pupils to be active report improved behaviour and results. Yet what makes one child more enthusiastic about exercise than another is complex. Ego, self-esteem, role models, and cultural and social factors all play a part. A British Heart Foundation study of 2,500 11 to 15-year-olds in the US and the UK found that those who exercised the least also did the least homework and socialised less than those who were active.

Encouraging children to change their lifestyle is a delicate task. Another study by Professor Biddle and C K John Wang says that many young people see no point in doing sport, lack confidence in their ability, and believe they cannot improve. They need to have more control over what they do, to experience success and to see sport as a skill they can learn. Above all, teachers and researchers agree, exercise must become a case of “I want to” rather than “I ought to”.

A stitch in time. . .

Inactive children do not become active adults. And the dangers that lie in wait for inactive adults, such as heart disease and high blood pressure, are well known. Unfortunately, an active childhood does not protect against the sins of a slothful adulthood. Schools need to equip children with the skills and the desire to carry on exercising throughout their lives.

Nevertheless, active youngsters do reap some immediate health benefits, such as lower weight, enhanced immune systems, reduced stress and anxiety, improved self-esteem and, particularly for girls, healthier bones. Girls who do little weight-bearing exercise, such as running and walking, risk failing to increase their bone density enough to protect them from osteoporosis later in life.

Too much exercise can also cause problems. As well as “over-use” injuries, young people can be at risk of exercise bulimia where sport rather than food becomes the obsession. Four per cent of Americans - adults as well as children - are reckoned to struggle with excessive exercise, and numbers are rising.

The problem with girls

Christine Beese, a PE teacher specialising in health and fitness at Oldfield school, a specialist sports college in Bath, says that many girls arrive at school never having experienced a raised heartbeat “and are frightened of the sensation”.

Forty per cent of girls drop out of school sport completely by the time they reach their teens, the Youth Sport Trust reported in 2000. The reasons for their antipathy are complex. American feminist researchers say men are part of the problem: from the eight-year-old boys who refuse to pass the ball, to the 18-year-old elite athletes who are taught to dehumanise and degrade women in their training. The problem must be tackled, they say, because the benefits are huge. As well as osteoporosis, regular exercise through child-bearing years is thought to reduce the risk of breast and ovarian cancer. And the effect of exercise on self-esteem is huge. Athletes, whether they are rural Hispanic or suburban white girls, are more likely to go to college and to aspire to be community leaders. The feminists’ call for improved sport for girls to speed the “feminisation” of power in all areas might raise eyebrows at Lord’s cricket ground, but there is little doubt that sporting machismo alienates many young women.

Girls in the UK told the Youth Sport Trust that competition is “unfeminine” and that they find the emphasis on winning intimidating. They don’t like communal showers or the traditional short skirt and knickers kit. They do like aerobics and swimming. They sense that hockey and netball are undervalued and would prefer to play football and cricket.

Whatever they do, says Christine Beese, it has to be fun. “I tell them to go for a cycle ride, to meet up at the swimming pool, to run to the other side of the field and chat about what they saw on telly last night. We don’t do fitness ‘testing’, we do fitness ‘profiling’. We don’t do ‘bleep tests’, which mean you have to run until you drop and are guaranteed to put anyone off. And we don’t play hockey, we play rugby.”

Primary schools

Last year, the Government declared that all children were “entitled” to two hours’ physical activity a week. Despite many initiatives and much hand-wringing, most still do not get it, says Professor Armstrong.

Yet primary schools, with parents, are central to making exercise fun and routine. Enjoyment goes hand in hand with achievement and, he says, youngsters are being rushed into competitive games before they can throw, catch or kick properly.

But primary schools do have a problem. Only 5 per cent employ PE specialists, only half have playing fields and fewer than one in 10 has a gym or swimming pool. The time they devote to PE has also dramatically declined since the introduction of the literacy and numeracy hours. In 1994, 32 per cent of six to eight-year-olds, and 46 per cent of nine to 11-year-olds, were bending and stretching for at least two hours in school every week. By 1999, this had dropped to 11 per cent and 21 per cent respectively, according to a major survey of 3,300 children and 151 teachers. Sport England, which carried out the study, worries about the effect on deprived youngsters whose families cannot afford to get them involved in out-of-school sports.

Some primary schools have come up with imaginative solutions to this time-and-motion problem. Many of these have been documented by the Qualifications and Curriculum Authority for its major study of PE and school sport. Giving a structure to playtimes that includes an organised activity - juggling or skipping, for example - helps. Offering unusual activities such as sailing or climbing can also do the trick.

Secondary schools

Until the age of about 10, boys and girls are more or less equal in terms of skills, and both tend to rely on parents and teachers to judge their progress. During adolescence this changes, according to research in 1996 by American academics Maureen Weiss and Vicki Ebbeck. Girls still turn to adults, while boys, who are more motivated by winning, start to rely on results and on their own opinions. Teachers and parents, therefore, can have a greater influence on teenage girls’ activity than on boys. But they face a problem with both sexes: adolescence. Researchers report a dramatic decline in activity (including some reduction in TV viewing) around the age of 13. Girls are particularly vulnerable, and secondary schools, says Professor Armstrong, have to get the balance right between competitive team games and individual pursuits such as aerobics and dancing.

Steve Dinnie, sports director at South Dartmoor community college - one of the first specialist sports schools - organises a healthy mix of activities. At key stage 3, all pupils do football, rugby, gymnastics and dance. At key stage 4, the aim is to find them an activity they will pursue into adulthood. They can choose, for example, golf, trampolining or street or step dance as well as the more conventional sports. There is also expedition training for the Dartmoor Ten Tors race, Duke of Edinburgh awards, and sailing.

Recognising the importance of adult role models, the college has many non-PE staff who use school facilities to keep fit. It was also the first sports college to focus on its feeder primaries - now a requirement for specialist status. After all, says Steve Dinnie, it can be difficult to change a 14-year-old’s attitudes which have been honed through sometimes unhappy school experiences. “You need to get them at day one in primary school,” he says.

Disabled children

Nine out of 10 disabled youngsters want to be active, but most are denied the opportunity, a survey by Sport England in 2000 reported. Roughly half of primary and secondary-aged disabled youngsters spent less than an hour a week doing PE at school, with 10 per cent doing no sport at all. Those who attend special schools fare better. When it comes to out-of-school sport, the barriers are still up. Young people say they feel inhibited, they suffer discrimination, and there are far too few suitable facilities. Given the chance, they say they enjoy swimming and horse-riding as well as football, netball, cycling and basketball.

Out-of-school sports

Most young people take part in some out-of-school sport. Seventy-nine per cent of six to 16-year-olds in 1999 exercised in their leisure hours. Almost 90 per cent said they played at least one sport frequently and one in three said sport was their favourite leisure activity. Their top five activities were swimming, football, skateboarding, basketball and aerobics.

But these figures are less healthy than they seem. Sport England reckons participation is falling. Its new report, Participation in Sport: past trends and future prospects, estimates that the proportion of people - adults as well as children - engaged in any sport will have fallen from 52 per cent to 46 per cent by 2026. Almost one million fewer people will be donning their trainers and tracksuits - unless schools and parents can fight the tide of inactivity.