This is Pretty Good:
http://www.youtube.com/watch?v=7D0DqEsohNM
BUT he goes too Fast on the Positive Part ( the flexing) and almost over looks that part Totally.
Thats the Part that Will Shape and engorge the muscle with Blood Volume.
His Negative ( the lowering of the weight is Very good)
I tried to find a better vid but could not.