Body Saw (with Towel or Slider)
To do the Body Saw, set up in a plank position on your forearms with your feet on towels or sliders. Elbows should be under your shoulders and your feet should be together. With your body in a nice straight line from your head to your heels, slide your feet back and lengthen through your arms. As you slide back you should extend your body down to your elbows, shifting your shoulders back behind your elbows. Do not let your hips sag as you slide back. You are extending your triceps as you slide back.
Then, using your lats and core, pull your feet back in to the plank position. When you come back into the plank position, do not let your butt go up in the air. Make sure your hips don’t sag either.
Then slide back out, lengthening your body out as much as you can. Again do not let your low back take over. Make sure that you also aren’t simply sliding forward and then back to the start but are actually sliding back and lengthening through your triceps and lats.
To regress the movement, beginners will want to do it without the towels or sliders. See that move HERE.