Swiss balll crunch

Is there an alternative to this one?  I must be doing it wrong, because I don't feel a thing.  I prefer the prone jacknife - that one I feel working.  Is there another ab exercise that I can do instead of the swiss ball crunch or should I just skip it? 

Make sure you are "pulling in" all of your stomach muscles, and do the crunches slowly so you can feel all the muscles working.  If I just do some crunches, I don't feel anything either, but if I really work on contracting the muscles as I do it, then I do get fatigued by the end.

I didn't feel these at first either.  I started doing the hands above head variation (I think they show an illustration in the book), and eventually added weight (10lbs) to that.  Now I can barely finish the 3x15 sets!

Original Post by awestendorf:

I didn't feel these at first either.  I started doing the hands above head variation (I think they show an illustration in the book), and eventually added weight (10lbs) to that.  Now I can barely finish the 3x15 sets!

There's an added weight version?  I find these incredibly easy as well.

Next workout I do these I'll do the above the head version.  Hopefully that will make them harder.

There are actually several variations.  You can keep the original form and just hold a weight against your chest - I didn't care for those.

I'm pretty sure the book shows the above-the-head variation, and describes adding weight if you need to.  I'm up to 15 lbs for stage 2 (10x2) - still killer!  The 3x15s were the toughest though.

At first I didn't feel it either, but than I started to curve my body back as far down on the ball as I could go, while having my hands overhead.  I go slow, and find it's really hard to do the last reps. You don't need to come up to a full sitting position.  Make sure to tighten your stomach through out. You should be feeling this below the bellybutton. If you'll know when your doing it right, trust me!