Children and teens can spend hours sitting in front of a TV, computer, and video game. The statistics are scary: Kids younger than 8 spend an average of 2.5 hours watching TV or playing video games every day, while kids 8 and up spend 4.5 hours in front of a screen. And you can’t rely on physical education (PE) classes at school to give your children the exercise they need, as many schools are cutting down the length of PE classes and even on recess.