A closer look at the abdominal muscles and one can see the ABS are organized as broad sheets of muscles in comparison to the biceps group, for example. Why is this important? Because when training the ABS this picture and concept needs to be in the back of your mind when designing a program to build a well-balanced set of musculature. Equally important, the way a broad sheet of muscle fibers is trained is not the same as the biceps. The ABS are mix of different muscle fiber types with varying ranges and fiber directions. Exercise selection, range, reps, and volume all need to be respected in a well-designed abdominal periodization.