Nearly half of secondary school girls and more than a third of boys fail to do the equivalent of 10 minutes brisk walking during three school days, according to unpublished research from Exeter University.
Neil Armstrong, professor of health and exercise science, said children were even more torpid on Saturdays, with 92 per cent of girls and 71 per cent of boys not raising their heart rates to the level of a brisk walk. During the course of monitoring almost 750 ten to 16 year-olds, he found the change in heart rates during PE lessons was barely perceptible in some pupils.
"Children have surprisingly low levels of habitual activity," he said, adding that very few satisfied the recommendations made by a recent international conference on physical activity for adolescents.
The first said that all young people should be physically active daily as part of play, sport, work, transport or recreation in home, school or community activities. The second recommendation said adolescents should have, in addition to daily lifestyle activities, at least three 20-minute sessions a week of more vigorous levels of exertion.
Professor Armstrong found that younger girls did more exercise than older ones, with teenage girls exercising much less than boys. He said young people should be exposed to a balanced programme of competitive, co-operative, individual and team activities as a foundation for an active lifestyle in the future.
Competitive team games dominated secondary school PE, but there was little evidence to show that young people continued once they left school. And many girls rejected competition, even those who exercised regularly. Team games' dominance might well contribute to girls' low levels of physical activity, he said in a paper presented to a recent European conference in Spain, which will be published later next year.
His findings lend weight to the Sports Council's National Junior Sports Programme, launched earlier this year, which aims to create a continuum from primary through to secondary and club level.