This article was reviewed by Craig Primack, MD, FACP, FAAP, FOMA. “Right to the core,” “core values,” and “hardcore.” These little idioms highlight just how vital the concept of “core” is in our lives ...

Exercises like push-ups, crunches, planks and Russian twists involve the hands, forearms, buttocks or the back touching the ground. But what if you don't want to sit or lie down or use your hands to ...