Sit ups might not always be the most exciting gym move, but you’ll love the results from these variations. (GIFs by Demand Media Studios) Sure, crunches and sit-ups can be monotonous, and they likely ...

The reverse crunch is a challenging core exercise that primarily hits your rectus abdominis, the muscle in your abdomen that makes up your “six-pack.” It’s a simple exercise that you can pick up in ...