When you train with resistance bands you often look for a place to attach them at a certain height to do different exercises. A door can be found everywhere so this suddenly makes it a lot easier and the number of different exercises you can do with your elastics is suddenly more than doubled!
I often have trouble finding enough variation in my workouts, you often fall back on the same exercises, but by attaching the elastic a loop higher or lower, you strain the muscles slightly differently, which increases the effectiveness of the workout.
Make sure that you attach the anchor in such a way that if you apply a lot of force, the door will be pulled into the frame.
