As with any form of fitness there are exericses that target muscle groups and even more exercises that target multiple muscle groups. Pilates is no different. Below are some repetoires of exercises, essential being exercises that a new comer would start with and intermediate being exericses someone with a little more experience would tackle. However, I do not feel that anyone, new or experienced at Pilates, should feel that they should follow one repetoire over the other. There are a few fundamental exercises that are a good place to start learning from when first starting Pilates but these fundamental exercises are also a great challenge for more experience Pilates practioners.
Essential Mat Repetoire
Intermediate Mat Repetoire
Essential Reformer Repetoire
Intermediate Reformer Repetoire