[missjane]

Another tip I picked up during my core classes regarding the long lever arm during crunches is to 'glue' your arms to your ear. Do not allow your arms to propel you up during the crunch and make sure those arms stay right there the whole time. Also, to now allow the ball to roll back and forth as you crunch.

I see lots of balls rolling back and forth and lots of long arms moving back and forth at my gym. When I really concentrated on both of these things, and really worked the crunches slow and contracted on each crunch, it made them a lot more difficult.