Looking to start the Martial Arts again-

Can anyone give me some advice or opinions-
As a younger child I achieved my red belt in Taekwondo. I soon after quit (bad mistake) and I would love to start again. I am now 15 and it has been at least 3 years since I stopped my training. I can't remember much, and I am not in the proper shape to study the arts at the moment (lack of flexibility). If anyone has any ideas on how to get in shape again or anything concerning the topic, please post-

Well from what I have read a good website about workouts and stretching is: http://www.stadion.com/column.html

You worry to much, just get back to the dojo and it will all start to come back. 15 years old, you have a life time ahead of you.