The Shadow said:by keeping constant tension on the muscles.....there is a restriction of blood flow....much like a limb falling alseep at night(like the other thing you mentioned).
You will begin to notice your vascularity "pop"......common theory says that you cant train for that.
Wrong.
...and it will become evident that the thought that you cant is just a gym myth.
Shadow so TUT can bring out vascularity is what your saying? It makes sense when I do a longer contraction especially with bies and tries too, I start to see things poping.