In my experience abs have been the must difficult muscle's to gain, they often frustrate me because they never seem to gain, although mine are hard as a rock. I do my ab workout with my back and bicep workout, it goes: back, biceps, and then abs last. I also use the ab machine with 50 lbs on it, I usually do 3 sets of 10-15 reps and I do that 3 times a week just like these guys are saying, I have a six pack but it shows very minimal. I don't get it, I have been doing what these guys are saying to do and it's not working one bit. I don't have much fat at all (see my pics in the pics section) so my abs should be showing A LOT more. 