In my mid 30's I have to stay sharp! I NEED to train in a CERTAIN way so that I can employ my fast twitch muscle fibers & nervous system.

IF THE NERVOUS SYSTEM IS THE SOFTWARE OF THE BODY THEN THE SKELETAL MUSCLE/FIBERS/TENDONS/LIGAMENTS ARE THE HARDWARE. This kind of training helps train both so that my nervous system TRUSTS my hardware without lifting heavy weights slowly- but moderate/light weights quickly! So that I don't slow down because I am NOT a bodybuilder