I found CTX a welcome change after doing a PS rotation. However to not lose any ground, I found that I had to work each body part twice a week. I did CTX Leaner Legs and CTX Power Circuit in their entirety each once per week, for the other days I did the remaining CTX series adding on additional body part. For example, I'd do CTX Kickbox and its bicep portion, plus just the tricep portion from 10-10-10. On another day I would do 10-10-10 in its entirety plus add on the Kickbox bicep section. So I'd work biceps, triceps, chest, and shoulders twice a week. Hope that helps.
Stacy