I have been working out hard for about 6 to 7 years now, and my ab muscles are really strong(from doing various medicine ball situp throws to leg lifts to crunch machine with like 150lbs) BUT I have never had a fully developed 6 pack (non flex) except when I used to wrestle and I was cutting weight . now when I flex, my abs actually pertrude and you may see a slight 4 pack. My stomach is not Flat but my abs are strong, I want a 6 pack or at least a flat stomach, what do I need to do?