Designing flexibility into habit frameworks

Reading a recent blog post by Peter Janiszewski made me think about designing flexibility into habit frameworks. For instance, Peter proposes a plan to increase his daily activity level by taking a mini exercise break several times a day. Each break consists of 3 sets of 30 repetitions. He never performs the same set twice in one day and selects the sets in a given break so that he exercises core, upper body, and lower body. Thus, he has a general structure in place to minimize the risk of overexercising specific muscles, but he does not plan out the sequence of exercises he is going to do in advance. By relying on a core set of exercises he already knows well and these self-made guidelines, he can exercise on autopilot if he feels less motivated. For the times when he wants to make things more interesting, he can mix up the sequence or improvise a new type of exercise. Establishing a framework for habitual behavior while making room for variation and invention seems to me like a good idea for sustaining behavior change over time.