Help with growing pains?

The constant stopping when running sprints can lead to pain and stiffness in the joints, its really hard on your knees. An anti-inflammatory should help. For future reference, try to minimize sudden jarring stops when runnning sprints. To avoid future muscle pain you should stretch thoroughly before and after strenuous activity. the 2 minutes of "stretching" that most amateur athletes do is sad. Watch the 300 pound football players warm up next time you watch an NFL game. Those guys can put their head on their knee. They stretch and warm up for a minimum of 30 minutes before a game.