Athletes of all sports—from baseball to football to hockey—base their physical training on improving the strength of their core using compound movements. That’s great for pro athletes, but what about guys who just want to get ripped abs? Regardless of where you fit on the fitness spectrum, the best ab workouts should comprise three planes of motion: frontal, sagittal, and transverse.

Myriad total-body exercises hit your core, but targeted ab workouts can really make a difference in strengthening your core from every angle. And doing core exercises in a circuit keeps the intensity high and will likely lead to more fat loss.

But we need to acknowledge a hard truth: Not all six-packs 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.