This is a great illustration of the abdominal muscle structure.  Notice how there are several sections.  You want to include exercises in your routine that engage all sections and often in combination.
There is so much involved in getting a 6 pack.  As honest trainer will tell you that it is more about diet than it is about exercise, with the exception of those who have it in their genes.  You know the 24 year old guy, who drinks 4 nights a week, and only eats crap.... Read more »