Forget crunches. If you want to get faster, fitter and stronger, you need to train your core like a runner In the past you'd have been hard-pressed to find elite runners paying attention to their abs.

Core-focused exercises for lower abs including crunches, planks, and twists.

Add Yahoo as a preferred source to see more of our stories on Google. DEVELOPING THE TYPE of six-pack abs guys dream about can be a time-consuming process that requires discipline both in and out of ...