If you know ANYthing about the CNS you should know. All movement is controlled by the CNS, contracting a muscle is an act of the CNS, when you train to 'failure' (which should be better said momentary muscular fatigue as actually the muscle isnt failing) your CNS is what is failing not the muscle. The CNS doenst process the ability to contract the muscle due to fatigue. If you care to start quoting Manning, Brzycki, Jones,Lyle to back up your claims be my guest.. I'll rip them a new asshole like I have forever now, HIT science is the most incorrect science on earth.
Kc