The most asked about muscle group without a doubt, has to be the abdominals. This is next to the glutes of course. Everyone is looking for that nice flat stomach, or the washboard six pack. This muscle group also takes the most work.
Without the right nutrition plan, you can do all of the crunches in the world & it won't make a difference. Your abs are covered by a layer of body fat. If there's too much body fat, you won't see the results of your efforts underneath.
Genetics comes into play too. Some people were born with fitness model bodies. Some people have to work a little bit harder. That doesn't mean it can't happen at all, it just means that it will take a hell of a lot more work than the genetically gifted.
So, with nutrition & genetics aside, how do you get the coveted six pack? It all starts with anatomy & working from the inside out.
Most people want to worker their "lower abs". What they really want to work is their deep internal muscles that support the body. The Transverse Abdominis. The core.
The best way to start working your core is using the "drawing-in maneuver". It's as simple as pulling the navel in toward the spine. You want to focus on the region just below the navel pulling in as well.
You should do this all day long. In your computer chair at work, while you're out & about running errands & most definitely during every single exercise. This maneuver activates your core, not only making it stronger, but stabilizing your body helping to prevent injury to your spine.
If your abs are strong from the inside, the outer muscles, the Rectus Abdominis, will work more efficiently. Then you'll be on your way to a kick butt set of abs that you'll want to show off.