The PE kit is washed and bagged, ready for a new term. But new research is
about to reveal how important it is that your children get to use it. An
important new study of UK schools indicates that pupils who do more physical
education at school have significantly smaller waistlines. This is a
significant contribution to the debate about whether it’s fitness or food we
need to concentrate on if we’re seriously going to address the nation’s
“obesity epidemic”.
It’s a subject we really do need to address: about 16 per cent of 6 to
15-year-olds are now obese, and doctors have warned that 20 per cent of boys
and 33 per cent of girls could be clinically obese by 2020.
The study, supported by Cancer Research UK and to be published in the International
Journal of Obesity next month, will show that boys in secondary schools
that provide three PE sessions a week have waists about 3cm (1.2in) slimmer
than boys at schools that provide one or two sessions. The study also showed
that, while waist size for girls in high-PE schools was smaller, the
difference was less pronounced.
The extent of this difference surprised the lead researcher, Professor Jane
Wardle, the director of the Cancer Research UK Health Behaviour Unit at
University College London, who says: “We were quite struck by the results.”
The study examined the progress, over five years, of nearly 3,000
schoolchildren from the age of 11 at 34 secondary schools in London. It
found that over that period there were consistently lower gains in waist
circumference in boys and girls from schools that had more PE. The
difference in waist size between the children getting the most PE and the
least PE was 4.5cm after just four years.
The research comes at an important time because the debate about whether
children are getting enough sport at school has gone quiet recently. This is
partly because schools appear to be on course for the government target that
by 2010 all children should receive at least two hours of sport and
recreation a week as part of the curriculum. A 2005-06 school sport survey
found that 80 per cent of pupils in schools within “school sport
partnerships” participate in at least two hours of PE and sport a week.
Critics, however, point out that the partnerships (government-fostered links
between schools and sports colleges) cover only about half of schools, and
half the sport recorded in the survey was outside curriculum time.
Margaret Talbot, the chief executive of the Association for Physical
Education, says: “What we don’t know at the moment is exactly how many
schools are providing good quality and active physical education within
schooltime.”
The food-or-fitness debate has also become more subdued because recent
research about childhood obesity has suggested that the amount and type of
food that children consume, and the amount of activity they get outside
school, may be more important than “formal” physical education. A
government-backed project in Plymouth, called the Early-Bird study, appears
to suggest that no matter how much exercise children are offered, they tend
to find their own level of activity; if they don’t get much at school,
they’re likely to make it up at home. The leader of this study, Professor
Terence Wilkin, from Peninsula Medical School, Plymouth, believes it’s not
our environment that determines activity but an in-built activity regulator,
and in some children it is set differently from others.
But now the balance of evidence may be shifting. In May, research involving
5,500 children from the Avon Longitudinal Study of Parents and Children
suggested that an extra 15 minutes a day of moderate or vigorous exercise
halved the risk of obesity in 12-year-old children. And now the new Cancer
Research UK study makes a convincing case that school exercise can make that
crucial difference.
“It’s an interesting study that raises a few questions,” says Dr Ian Campbell,
a GP specialising in obesity issues and chairman of the National Obesity
Forum. “It would suggest that physical activity at school can be a useful
way of tackling at least some aspects of childhood obesity, and would
support the calls for greater priority to be given to PE lessons at school.
“Obesity is such a complex issue that it can’t be explained simply in terms of
PE at school or any other isolated feature. But I do believe that schools
hold one of the keys to tackling childhood obesity in that they present a
fantastic opportunity for kids to learn about the importance of health, diet
and activity, and can lead by example in the canteen and the PE class.”
One of the key reasons that Professor Wardle’s study has picked up different
patterns from other studies into childhood obesity and exercise is that it
looked at the children’s waist size and not their body mass index (BMI).
Most studies use changes in BMI (a figure based on the ratio between height
and weight) as an indicator of how children are putting on weight over time.
But Professor Wardle was concerned that BMI measurements weren’t sensitive
to the fact that exercise, while reducing fat, builds up muscles. Waist
measurements are sensitive to this.
“Waist measurement is a much purer indication of fatness,” she says. It’s also
important because studies have shown waist measurement to be a better
indicator of the risk of coronary artery disease in adolescents than BMI.
Another reason to take it seriously is that it picks out the long-observed
difference to exercise at school between boys and girls. Though the girls’
increase in waist size over the five years was less with more school
exercise, the change was not large enough to be statistically significant,
unlike the pronounced pattern in the boys’ waist sizes.
“We suspect that this is because girls tend to go off games much earlier,”
says Professor Wardle. A big study by the Institute of Youth Sport at
Loughborough University in 2005 found that girls hated school PE because
they disliked the kit (30 per cent) and were self-conscious about their
bodies (40 per cent). One girl in five said that she took part in PE only
because she had to.
The new study doesn’t provide all the answers on how we prevent young people
becoming overweight. But it does tell us that we shouldn’t let the
Government off the hook on school exercise. And if that gym kit does get
lost, dirty or worn out during the term, it’s better than it not being used
at all.
How much PE do children need?
The Department of Health recommends that children between 5 and 18 participate
in at least one hour of moderate-intensity exercise (eg, swimming, cycling)
every day. Norwegian scientists in The Lancet last year said that
children engaging in 90 minutes of moderate exercise a day are less likely
to have heart disease, high cholesterol or high blood pressure. A 2006
study at Glasgow University found that the recommended level of adult
exercise – 30 minutes, three times a week – isn’t enough to have any effect
on weight control in kids.
