Will I survive having a teenage runner girl???

Where do I even begin? Having a teenage runner girl is like nothing I have experienced before. They are......aliens I believe!

They are emotional, irritable, sassy, sweet, cute, mean, smart mouthed, loveable, needy, social butterflies, bored, too busy, etc, etc, etc.

My teenage daughter is a runner, a very good runner. The problem is she is addicted to the sport. She has started training for cross country with her running club. They have gone to TN for a camp and we weren't able to make it this year. Her coach gave her a schedule to run and it contained a lot of mileage. As a parent, I felt it was too much for her to run. I have not let her run a couple of the days and asked her to cut back on a couple of longer mileage days. Well, I took her running yesterday and told her that 6 was her maximum miles that day. We finished up 6 and I told her that we were done, well she decided that she WAS going to run 7 and took off running and left me behind. I was NOT a happy mother. My first thought was to spank her when she returned, but decided I didn't want Child Protective Services called, so I gave the same lecture that I have been giving her for the last year or so...cut back on the running and/or eat more calories to supplement the increase in mileage.

I am stumped as to what to do with her...have her see a therapist, stop her running? I don't know, I need help. I can't force feed her and the bad thing is, she is a really good runner!!!

I need help!!!