People are writing as never before--in blogs and text messages and on MySpace and Facebook and Twitter. Teenagers do a good deal of this writing, and in some composing environments--for example, the text-messaging space of a cell phone--they are ahead of adults in their invention of new writing practices and new genres. At the same time, teenagers…

Background: While studies have determined the importance of physical activity in advancing health outcomes, relatively few have explored the relationship between exercise and various health behaviors of adolescents. The purpose of this study is to examine the relationship between frequency and intensity of physical activity and both health risk…