in my opinion you wont start to see those bad boys until you get to a low bodyfat percentage. i work my core everyother day (that works for me, might not work for everyone) and i didnt start to see them until i hit 11% bodyfat. you also might have loose skin hanging out. your core will always have a small amount of fat to protect organs but you can get ripped if you work hard enough. only advice i can give is eat primal.