SLDL's are always incorporated into my back workout. In fact, I have added leg curls to my back workout, while my leg workout does NOT include hamstring work. I have read many articles that state you cannot get a good ham workout in if you are blasting the quads on leg day. Seems to be working, as my hams are coming out more, and back day is a more rigorous workout now. Stiff Legged version also brings out the obliques.