Researchers today warned of serious health risks for children with more than two hours daily television viewing - as New Zealand broadcasters said their average viewer last year watched for a record average of three hours and eight minutes a day.
A team of researchers from the New South Wales Centre for Overweight and Obesity said today those children and young teenagers who spend more than two hours a day in front of computers or televisions were significantly less likely to be fit.
Led by Louise Hardy, of Sydney University, the team surveyed 2750 students aged 11-15 years and found strong links between their cardiovascular fitness and screen use.
Published in the February edition of the American Journal of Preventive Medicine, the findings mark the first physiological evidence supporting 2001 guidelines by the American Academy of Paediatrics (AAP) for a two hour cap on sedentary behaviour for children.
"Our findings represent the first physiological link between more than two hours small screen recreation and lower aerobic fitness," Dr Hardy said in a statement.
The researchers also found that girls were more likely to experience lower fitness as their sedentary behaviour increased compared with older boys whose fitness was less affected.
"These boys, who would be over 15 years, probably have developed enough muscle mass which allows them to `sit and be fit'," Dr Hardy said.
But most children needed to exchange excess "sitting time" for "active time" and to limit their time in front of a screen to less than two hours a day to maintain fitness levels: "No-screen days would be even better".
Rick Friesen, chief executive of the NZ Television Broadcasters' Council, announced a new record average viewing time of 188 minutes in 2008, up 8.6 per cent on 2007.
"This is the highest level of television viewership achieved in New Zealand since records began," he said yesterday.
Viewing numbers were highest on Saturday and Sunday and the council said that on average 2,452,600 people tuned in to television at some point each evening, up from 2,360,400 in 2007.