Using blogs to expand the classroom

I teach eighth grade physical education at a middle school in Renton, Washington.  Although I am a complete novice to blogging, I feel confident enough to use this technology as a way to enhance my classes and expand the borders of the classroom.  Being a physical education teacher, I am constantly encouraging students to continue or become physically active outside of school.  The world we live in today has blessed us with tons of new and exciting forms of technology to make things easier or entertaining for us.  However, it has also made us lazier and sadly lazy does not equal healthy.  I would have my students showcase their outside school activities and use the blogging sites as a way for them to share their achievements with their classmates and myself.  I can post weekend goals/activities for the students to accomplish over the days off and they could respond before we see each other on Monday.  Another great time to make use of the blogging sites is during the extended breaks.  I generally see setbacks in students' fitness levels after breaks; holidays, large meals, vacations, tend to lead to less exercise.  I could post motivating messages, even if they are just reminders to get an hour of physical active everyday!