
Originally Posted by
pebble
dec11 - Are you trying to say words like force, transfer, and hypertrophy have no place on a training forum?
OP, The reason I asked is because the abdominals primary role is to transfer force between the lower and upper body. For sports this is usually accomplished by training with stabilization techniques (i.e. planks) or rotational techniques (i.e. barbell twists). Seeing is your goal is solely aesthetics your exercise choice should be based around hypertrophy (muscle growth) training. I would suggest training them with a variety of rep ranges (5-8, 10-12, 15-20, and even >20) because they are postural muscles that are used all the time. This also means that you can train them more frequently because they do not fatigue as easily. You could easily get away with training them every other day without problems (as long as you do not cause excess trauma on the days you are working out).
To answer your question I would say 3-8 sets depending on how many reps you are doing. Sets and reps have an inverse relationship. This means that when you are doing 20+ reps you should be using a lower amount of sets for this example 3. But if you are doing 8 reps, 4-6 sets is likely more optimal. Don't forget that if you are doing fewer reps, it is smart to choose an exercise that resistance can be added to such as cable crunches, whereas with higher reps an exercise such as leg lifts is a better fit.
Diet (hypocaloric - less kcal than you need) will play a bigger role than the exercises you choose in making your goal happen. You need to reduce fat and allow your abs to be visible.