Most school children in Britain are not getting enough exercise to keep healthy, according to a charity.
The British Heart Foundation says you should spend an hour a day playing or doing sport, but only one in every eight kids get that amount of exercise.
Their report found that most kids spend more time texting mates or surfing the internet than having a kick around at the park.
They predict that almost 70 percent of children will be overweight by 2050.
Keeping active is really important. If you don't take enough exercise you are more likely to suffer from illnesses like heart disease and high blood pressure in later life.
Athlete Sally Gunnell is backing the campaign to get more kids to do sport. She says: "It's something that all children should enjoy as part of a healthy lifestyle and is also a great way to socialise with friends."
The charity's report is based on the exercise habits of 1000 children aged between 8 and 15.