How do i get tighter abs?

I hit my gym 3 times a week each time for 1 and a half hour, should i add swimming? would 2 times be good? i have a normal body, i'm not fat or small. I eat good stuff and drink fast carbs pre- and protein powder post workout. i want my abs smaller and more tight, so sit ups is useless for that, right? should i do plank exercises?
THX

ck2014-04-06T12:32:03Z

do situps, planks, and russia twists for the obliques. Remember the ABs have multiple zones so be sure to exercise each of them. Swimming and all cardio exercises are good to keep fat levels down.