A study in the Archives of Pediatrics & Adolescent Medicine showed that children need only seven minutes of intense exercise daily to stave off obesity and related conditions. However, researchers found children spend almost 70% of their time doing sedentary activities, 23% engaging in light physical activity, nearly 7% doing moderately physical activities and only 0.6% engaging in intense physical activity. Girls are less likely than boys to get vigorous physical activity, researchers said.