One thing I didn't see mentioned (sorry if I missed it) was ensuring that you're getting adequate protein for muscle building and maintenance. I tracked my diet for a few weeks when I transitioned to Primal and was surprised that my protein intake was below what was recommended. Once I upped it, recovery was better. I've been doing You Are Your Own Gym, not CF, but there were some intense workouts (like learning one-legged squats and one-arm pushups) with several-day-long DOMS. The other thing that sbhikes touched on that was crucial for me was enough sleep. Which goes along with work stress--if I've got a hectic work schedule, I just don't work out as hard--can't do it all at full intensity! Good luck with it.