I think when doing squats and deadlifts and other major compound exercises, you should really be focusing on calling your core into action here. I think you will do you spine some good if ALWAYS make sure you engage your core into these lifts. After speaking with some of my wife's colleges (Physical Therapists) they really recommend using your core as the foundation of these lifts. I'm not saying dont work your abs, I'm just saying focus on using your core more and more during squats and deads and you will develop them that way. I really love weighted decline situps and leg raises, but dont forget to work your lower back as well. YOu really want to work and create a tree truck of a core.