Excellent abdominal exercise. Choose a weight that is not too heavy to
pull down, but not too light that it makes counterbalancing and
stabilization difficult. Use a short (black) triceps pressdown-type
rope.
Three variations on this exercise:
(1) Both knees on dome side of BOSU normal or close or shoulder width
apart. Place the BOSU far enough from high pulley so you can get a good
stretch on the extended position.
(2) Both knees on dome side of BOSU in a wide or abducted position near
the base circumference of the BOSU. This position causes more work from
the adductors and lower parts of abdominal muscles working to stabilize
the abducted position. The adductors sort of grip the BOSU. Place the
BOSU far enough from high pulley so you can get a good stretch on the
extended position.
(3) One knee on dome side of BOSU with the opposite leg in a hip
extended position. Balancing on one knee can be difficult with extra
stabilization necessary. The external and internal obliques seem to work
extra hard to help with stabilization Place the BOSU far enough from
high pulley so you can get a good stretch on the extended position. You
may find you can only do about 10 reps of this exercise at first.
— mb