Our abdominal core is an amazing anatomical composition of 12 muscles that wrap around us like a girdle and when properly trained, holds our midsection in flat and tight. However, recent research shows that standard floor crunches train only 2 of these critically important core muscles. Developed by noted fitness expert Linda LaRue, her unique exercise method focuses on each core muscle like a laser, targeting your upper abs, those hard to reach deep lower abs, your left and right side obliques, and wrapping all the way around to your lower back.