This approach to weight training came along in the late 50's and is still used in gyms around the world today. Joe Weider preached this method through his media empire. It involves doing a lot of sets and split routines and requires a lot of gym time.
The muscles have to do a lot of work in this approach. An example would be doing 6 sets just for biceps. And that is just one muscle. It takes a lot to cover the whole body.
the German version of volume training is the 10 X 10 method covered in that section.