Feel free to leave the training mat hanging and stay on the ground–or better yet, get on your knees. If you should focus on just one abdominal exercise, it should be cable crunches. FITBOOK editor ...

Add Yahoo as a preferred source to see more of our stories on Google. fotostorm/Getty Images Gym machines help target and build specific muscle groups, making them great for ab exercise. Moves like ...

Your core is like a WI-FI router. When it’s strong, everything in your body is connected and working seamlessly. But when it’s down, random places in your body start hurting out of nowhere. The only ...