A survey of more than 2,000 nine to 18-year-olds in schools across Victoria has revealed that today’s students are slower, fatter and stiffer than their counterparts of a decade ago.

Among 12-year-olds tested by researchers at the Royal Melbourne Institute of Technology, both boys and girls took about a minute longer to complete a mile circuit than their predecessors in 1985. They also showed less physical flexibility in hamstring stretch tests.

Children tested on lower back and hamstring flexibility were significantly less supple, the survey found. On sit-and-stretch tests, the 1985 12-year-olds could reach nearly three inches further than those of today.

Medical experts say the results have serious implications for the health of these young people as they grow up.

According to the head of the research team, Dr Jeff Walkley, the decline in children’s fitness is due mainly to a reduction in physical education and sport in schools and a big increase in sedentary leisure activities such as videos and computer games.

Social factors such as both parents working and increased car use, as well as parental concern about children playing alone outside the home, were also contributing to the decline, Dr Walkley said.

A previous study that looked at the motor skills of 1,200 children in Victoria showed that they were poor at playing typical schoolyard games such as throwing balls, running, jumping, dodging, catching and kicking. Dr Walkley said that children who could not perform well in front of their peers tended to avoid movement-related activity because it was no fun and they had no reason to improve either their skills or their fitness.

In New South Wales, another investigation has shown that children’s interest in PE classes wanes in Years 5 and 6, and that the older children are, the less likely they are to participate in school sport.