Inchworms are a different kind of push up, except you go in the opposite direction. You start out in the standard push-up position, and do a single push-up. Then you lift your hips as high as you can, so that your butt is in the air but your hands and feet are on the ground. Moving slowly, inch your feet toward your hands, but make sure you keep your knees straight. Then you slowly inch your hands away from your feet, so you're back in the starting position, at which point you lower yourself back into the push-up pose. When you begin, 10 reps are perfect.