Place your hands about shoulder width apart with your arms straight and your feet close together. You should tighten up your torso (by pulling your navel in toward your spine, so that your hips don’t sag). Your body should be in a straight line from head to heels; the neck should be keep in line with the rest of the spine. Execute the move by lowering your chest to the floor and tucking the elbows so that they form a 45 degree angle. Pause at the bottom and push your body back up to the start position. Throughout the exercise, keep your head and neck in line with the rest of the spine and the torso tight. Make this move less challenging by doing it on an elevated surface like a chair, bench, or wall. Or more challenging by stacking the feet.