Why aren't the Children allowed to get out and enjoy Recess @ Schools any more, isn't this a bad mistake ?

I personally feel our Children are kept inside too much, because after School hours a lot of our kids choose to stay inside, and play video games etc. It just seems they don't get enough exercise, or fresh air in their lungs, by not being allowed to run, jump,and yell, outdoors. What do you think, and what can be done about improving our Childrens' health when it comes to recess @ school ?