Elizabeth D Hello! Thank you for taking the class and the time to message me! I am so happy you love the abdominal work. This class progressed from one light yellow spring, then to blue, and on to the red and eventually heavier spring. I meant for it to flow from standing in the well at the back of the reformer to working my way up to the front. When I prepare a class, I think of the theme and where I want to start. From there I just start to move through exercises and flow them together as much as possible. That includes exhausting the use of the spring before I move on. Hope that made sense! :)