Some people I know train abs/core 'hard' and still don't look great, some people just can't get them like others can. A lad I was at my Para Reg Assessment course with had a stomach like I have never seen. He had an eight pack that looked like hot dog buns under his skin who NEVER trained his core, he looked like the 300 film cover. I thought he was full of shit until we did our PTA and one of the tests was max sit ups in 2 mins and he managed a lowly 54, considering some of us were doing 80-90
I found a routine of medine ball twist situps, crunches and toe touches with some dumbell core weight exercises along with a good diet worked wonders, but I was training for core strength rather than a beach body, abs were just a welcome by-product.
Take me for example, I look
in better shape than my cousin for example going on how my core looks
, but at the gym I stuggle to keep up with him when we do the circuit. I just naturally am more that way than he is.
Mind you, take on board what others say and work the rest of your body aswell. Having a washboard stomach and skinny little arms is almost as bad as a stacked weight lifter with chicken legs.