First off, let's acknowledge a hard truth: Not all abs are created equal. Some guys need to work their belly to exhaustion before they can carve out abs, while other dudes seem to get theirs to pop without a single situp.
Regardless of where you fit on the fitness spectrum, effectively training the core comes down to the three planes of motion: frontal, sagittal, and transverse. Doing abs exercises in a circuit style keeps the intensity high and will likely lead to more fat loss.
