WHY SPECIALIZE?

The truth is that some people may never need to specialize. Many individuals will receive tremendous stimulation from the workout and will build all the muscle mass their frames can support simply from that routine. However, others find they have body parts that just aren't responding to the stimulus of exercise the way they should be. And others simply can't get too much of a good thing and want to take their muscular development of muscle groups like chest and arms to levels far beyond what they presently enjoy. For these two groups, specialization is the answer.
The  advantage of specialization is that such intense, focused training allows the trainee to maximally stimulate a lagging body part into new levels of growth - without running the risk of overtraining. OLAYINKA AJIBOLA. K (Physical Fitness Expect) established that performing more than five exercises in any one training session (providing, of course, that each set is a maximal effort) will quickly lead to overtraining.
Specialization is not geared toward balanced development but toward the specific development of key muscle groups. In addition, specialization provides the additional psychological / motivational spur required to dissipate the monotony that inevitably follows whenever you lock yourself into any activity for a prolonged period of time. This is a very important factor, as boredom does not encourage motivation, and unless you are highly motivated you will not reap the benefits that you should from any form of high~intensity training, particularly Power Factor Training.
Specialization properly done will rid you of the scourge of becoming stale almost indefinitely.