Physical education in primary school children—not so bad for boys

A recent survey of children at primary schools in England found a marked decline in timetabled physical education between 1994 and 1999.  Sport England expressed concern about the impact of competing priorities on curricular physical education and concluded that children from poorer backgrounds would be worst affected. In this study the authors used accelerometers to measure the impact of timetabled physical education at school on overall physical activity in children.

The authors monitored physical activity during waking hours for seven days using accelerometers in 215 children (120 boys and 95 girls aged 7.0-10.5 years) from three schools with different sporting facilities and opportunity for physical education in the curriculum. 

School 1, a private preparatory school with some boarding pupils, had extensive facilities and 9.0 hours a week of physical education in the curriculum.  School 2, a village school awarded Activemark gold status for its focus on physical activity, offered 2.2 hours of timetabled physical education a week.  School 3, an inner city school with limited sporting provision, offered 1.8 hours of physical education a week.

The accelerometer electronically measures clock time, duration and intensity of movement, and is highly reproducible. A total of 74% (85 boys and 74 girls) complied with their accelerometers. School 1 recorded the most activity in school time but this was barely twice that of pupils in Schools 2 or 3  despite timetabling more than four times the amount of physical education.  Surprisingly, total physical activity between schools was similar because children in Schools 2 and 3 did correspondingly more activity out of school than children at School 1.  Among the boys, total activity was higher in School 2 than in School 1 and School 3 with mean  units of activity a week of 39.1, 34.7 and 33.7.

In general girls did less physical activity a week than boys (32.7 v 35.9), but their patterns according to school were the same.  Mean household incomes were 5.5, 4.3, and 2.7 units in the three schools .

The total amount of physical activity done by primary school children does not depend on how much physical education is timetabled at school because children compensate out of school.  This is unexpected, but encouraging, because the amount of timetabled physical education offered in School 1 is unlikely to be bettered elsewhere, and children from School 3 (the poorest) were not adversely affected. 

Less encouraging is that girls do significantly less physical activity than boys yet are known to have higher insulin resistance and triglyceride levels.  It may be relevant that more girls than boys develop type 2 diabetes in childhood.

The authors could not comment on whether physical activity among primary school children has declined, but found no evidence that children from poorer backgrounds are adversely affected.

Ref: Web

Back to top

Mediterranean Diet

As winter is here now may be the time to think of a Mediterranean diet. To some summer visitors to the shores of the Mediterranean, a Mediterranean diet might be thought to consist of lager and burgers, just in larger quantities than usual.

To most of us it is more like a Greek salad with lots of olive oil, grilled fish, and some fruit, all washed down with the odd bottle of vino. There are big differences in the diet and big differences in what that diet does for us.

Much has been written on the benefits of Mediterranean diets, and the particular components that make it better. A recent large observational study has made understanding this just a bit easier.

This was an examination of 22,000 Greek adults aged 20 to 86 years from all parts of Greece. Dietary intake for the year before enrolment was obtained by a questionnaire delivered by trained interviewers, and examined frequency and amount of food with photographs for estimation of usual portion sizes. The daily intake of 14 food groups or nutrients was obtained in grams per day for each participant.

Adherence to a Mediterranean style diet was determined with reference to some of these food groups, by the simple expedient of whether an individual consumed more or less than the median for their sex.  Possible scores were 0-9.

Individuals were followed up for 44 months, and the date and cause of death for any participant obtained from death certificates and other sources. Observers were blinded to the diet score of individuals.

There were 22,000 people with full details available. There were significantly fewer deaths among women than men, and more deaths in people over 55 years than in those under 55 years, and in current smokers, but fewer deaths in people who took more exercise.

Death rates in women and men were higher in those with a low diet score than in those with diet score of 4 and above. A two point increment in the Mediterranean diet score reduced the risk of death by about 25%. Effects were important for older people, those taking less exercise, and any level of BMI, as well as cause of death or coronary heart disease or cancer.

A randomised trial examined the dietary intervention of an Indo-Mediterranean diet consisting of a control group using the National Cholesterol Education Programme step 1 diet and the same diet with additional recommendations to consume every day at least 400-500 grams of fruit, vegetables or walnuts or almonds a day, 400 -500 grams of whole grains and mustard seed or soy bean oil. The aim was to provide plenty of phytochemicals, antioxidants and alpha-linoleic acid.

Patients were Indians with a documented history of coronary artery disease, and randomisation was stratified by risk factors. Follow up was for two years, and the principle outcomes were fatal or nonfatal myocardial infarction, sudden cardiac death, and the combination of these outcomes.

Each group contained almost 500 patients, and their average age was 49 years. Most patients had serum cholesterol between 6.2 and 6.7 mmol/L; about half were smokers at entry. About 30% were overweight or obese.

Reductions were similar for all components of the combined outcome. For every 14 patients exposed to the Indo-Mediterranean diet for two years, one fewer had a fatal or nonfatal myocardial infarction or sudden cardiac death than similar patients using a standard NCEP diet.

The gains are not trivial. The setting of the randomised trial was that of secondary prevention, where we expect NNTs over five years for statins of about 10-20. The Indo-Mediterranean diet had an NNT of 14 over two years, equivalent to an NNT of 5-6 over five years if the effect continued over that time.

Ref: Bandolier

Back to top