Standard abdominal crunches on the BOSU balance trainer are incredibly
challenging and isolate the abdominals very well.
Since the dome side of the BOSU is round it allows you to comfortably, slightly hyperextend your back to move through
a greater range of motion which is not possible when doing abdominal crunches on
In addition to the extra range of motion as in stability ball crunches, you can
really focus and isolate the abdominals when doing them on the BOSU because you
are lower to the floor with the full support of your feet.