Sure, you can do crunches until you’re blue in the face, but that won’t take you to hard-abs town. “That is the worst way to go about abs. You need to think bigger,” says Oprea. Meaning: Your core contains far more muscles than crunches can target, like your internal and external obliques. Make planks and wood chops (try them with a cable or holding onto a medicine ball) part of your regular routine. These bigger movements engage a larger range of muscles in your body.