There are two different options for calculating your SparkPeople calorie range. The one you're referring to will change your calorie range based on how much exercise you track. Here's an article that gives more detail on that method: www.sparkpeople.com/resource/nutrition_art
Hope that helps,
"You may have a fresh start any moment you choose, for this thing that we call "failure" is not the falling down but the staying down." Mary Pickford
"No matter how slow you go, you are still lapping everybody on the couch."