What you must do: hung with the horizontal bar, the isolated hands of the width of the shoulders, the thighs are folded and parrallèles on the ground, the knees are folded.
By contracting to you abdominal muscles, tend slowly and gradually the legs, then return to the starting position by folding the knees.
So that this exercise effective is made long series (until feeling a burn on the level as of your abdominal muscles).
Breathing: by carrying out this exercise expire (to empty the lungs) when you tighten the legs and inspire (to inflate the lungs) when E you fold up
knees.
