A charity has warned that most schoolchildren in the UK are not getting the hour of daily exercise suggested for good health.
Just one in eight, or 13%, get the required amount of exercise, while 30% get under an hour every week.
As many as 78% overall have no idea how much exercise they should be getting every day, while 30% said they "can't be bothered".
In the British Heart Foundation (BHF) poll of more than 1,000 children aged eight to 15 for the Food4Thought campaign launch, 20% said exercise was "a chore" meant for only overweight people.
But 55% of those surveyed text or chat with friends, or visit social networking websites for an hour or more every day. By 2050 experts forecast, two-thirds of all children will be overweight or obese.
BHF's director of prevention and care Dr Mike Knapton said: "We have a generation of kids growing up who have a shockingly blasé attitude towards exercise and being active."
The charity has unveiled an Ultimate Dodgeball challenge in UK schools backed by athlete Sally Gunnell.
Dr Knapton said: "Ultimate Dodgeball is a great way to get children interested in sport and physical activity - young people need to switch off their square eyes and get in the habit of exercising now."