If you need a bit more intensity than the basic crunch, go ahead and give this advanced ab workout a try. Most of the exercises can be modified to increase or decrease the intensity, but all are a step up from the basic crunches, sit ups and planks that may be a part of your usual ab workout.
If you prefer mixing and matching your own ab exercises to find the perfect challenge for you, take a look at the full list of abdominal exercises.
Do you have a favorite exercise that isn't listed? Share your favorite ab exercises.