How to stay in shape

You did the hard part: you put in all that effort and you got your body in shape. Congratulations! We're so proud of you. Now for the harder part (yes, there's a harder part): staying in shape while time constraints or other life factors keep you from maintaining your old activity level. It is important that you maintain a healthy diet and an active lifestyle. You can make your daily activities more active to help you stay fit. Make sure to eat properly for your new activity level, and fit easier exercises into the time that you do have.
So what are the reasons for staying in shape.