This concept or secret I've learned and implemented in Fat X 101 workouts and the 12 Day Fat X Program is the concept of synergy.
Synergy is what makes the exercises in each of the workouts interact and cooperate with each other in such a way that they produce a combined effect greater than the sum of it parts to produce a highly effective and efficient fat burning exercise program.
In putting together Fat X 101 workouts and picking exercises, not only did I choose high quality effective exercises, but I organized them in an order and intensity level (in respect to one rep max) to work synergistically and enhance the overall effect.
I've constantly been asked about "the secret" to the success of Fat X workouts and the 12 Day Fat X Program, and again it's not so much a secret as it is this very important and under utilized concept of synergy.
If you haven't already tried the exercise program, check out the free section. If you like those, you'll love the 12 Day Fat X Program.