To do the Body Saw, set up in a Plank position from your forearms and toes with your feet close together. Your forearms should be right under your shoulders and your body should be in a nice straight line from your head to your heels.
Then begin to walk your feet backward, taking small steps. Keep your body in a nice straight line and don’t let your hips sag toward the ground. Lengthen through your triceps and lats as you walk back. Walk back as far as you can while keeping your core engaged.
Then walk your feet back forward until you are back in the Forearm Front Plank. Do not let your butt go up in the air as you walk your feet back in.
Repeat, walking your feet back out. Only walk out as far as you can without your low back engaging. If your low back feels this move, don’t walk out as far. Start with only a few steps.