Athletes know the value of a strong coremore stability, power and a decreased likelihood of injury. Muscle sculpting fanatics, on the other hand, are obsessed with achieving as many grooves, nooks and cuts as possible. Regardless of whether you're solely going for function or aesthetics, this circuit training routine, compliments of Naudi Aguilar, owner and trainer of Functional Patterns, will shred every muscle fiber in the midsection simply by using cables. As always, diet and nutrition are equally critical to the abdominal equation, but give this style of training a shot. You'll feel it tomorrow.