In the United States today, we are starting to see more and more of a problem with children who are overweight. Doctors and are trying to do something about it. They are recommending healthier foods and that children get daily exercise. They also recommend that children go outside and do things instead of sitting in front of the TV. They have suggested that children get at least an hour of exercise a day by doing things like jumping rope or cycling, or anything else that makes their heart beat faster. This kind of exercise is known as aerobic exercise. Something else they recommend is for children to do exercises that strengthen the bones and muscles. There are lots of ways children can do this. One way is running.

What detail in the above passage explains what doctors want children to do?