Kids who spend ages lazing in front of the TV or playing video games are up to nine times clumsier than their active peers, Portuguese researchers have claimed.

Scientists at the University of Minho, Braga, looked at the movements of more than 200 nine and ten year olds and measured their levels of activity over a five day period.

They were also asked to perform tests, such as walking backwards on a low beam, hopping over some blocks and stepping between boxes without falling off.

Combined, the results were seen as measure of the child's co-ordination. The scientists found that, on average, children were inactive for three-quarters of the time, and although girls were more inactive than boys, the impact on co-ordination was seen more prominently in boys.

The findings, published in the Journal of Human Biology, even stood when factors such as height, weight and amount of strenuous exercise they did was taken into account.

Dr Luis Lopes, of the University of Minho said that co-ordination had previously been linked to healthy weight and strong muscles but that it requires "practice, encouragement feedback and instruction".

He said: "Childhood is a critical time for the development of motor co-ordination skills which are essential for health and well-being."

Story posted by Robert Mair on 15 August 2012