8% BF for fitness? not sure I have ever seen bodyfat levels this low on a woman that is not pro. unless you have a "Friend" doing your callipar test. I have seen women claim 8-10% range without one ab showing, and I almost have to laugh. Most women will start showing abs at the 16-18% range..... while a mans will start to show in the 10-12% range. Of course this is just a general guidline and everyone is built different..but ussually works out pretty close.
my wife just had her bod pod done (this includes visceral fat, fat around the organs, calipars dont count this)... she is 162 @ 14-15% (if you take viceral fat out) and has striations in her pecs , shoulders and most of her abs showing..... if your a female and someone does a calipar test on you, and tells you that your 12% and you dont have a full six pac....they did the test wrong. god forbid you let them do the hand held bioelectric test on you.