This exercise can be done with a barbell or ab wheel.
The elbows are to be locked and kept in a vertical
line with the shoulders. Many ab wheel commercials
show the user with their arms extended out but it is
felt that this puts unnecessary stress on the
shoulders and lower back.
Keep the body locked
in a straight position with no back "sag" when in the
bottom position.
All movement in this
exercise is initiated by the hips, not the arms/lats.
The emphasis should be on raising the butt as high as
possible in a "piking" motion.