There's a reason she's out there all alone. Children worldwide are spending less time on sports and active play and more time with TVs and video games. iStockphoto.com hide caption toggle caption iStockphoto.com Shots - Health News Kids Are Less Fit Today Than You Were Back Then November 20, 2013 Around the world, children are slowing down. Researchers have found that kids don't run as fast as they did in the 1970s. The finding suggests a potential uptick in future heart problems because running speed is a proxy for aerobic fitness and a measure of overall cardiovascular health.