While doing exercises for abs is important you gotta remember that how lean or ripped you are depends on your body fat percentage. You can do abs till your blue in the face... If you do not have your body fat percentage down then they will not show well. Clean diet,regular exercise and cardio consistency must be done to get your percentage down. Now those with a higher metabolism will tend to stay lean easier, and loose fat quicker. They may not even need Cardio either