Yes. If you click on Account Preferences at the top left of your Start page, about 1/2 way down you'll see the link to change how your calorie range is calculated. Making that change won't delete your past tracking, but it will help if your calories burned differs from week-to-week.
"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."