If we compare three days a week with the push/pull system for instance, you'll notice something interesting. Let's say you typically do 4 working sets for chest, and of course, on the push/pull system, that means 8 sets a week per chest exercise.When you shift to a whole-body, three days-a-week structure, you're now using 12 sets a week, since you'll now be training chest three days instead of two. That's a 50% increase. Seems significant, right?