It is easy to get caught in the isolationist trap. Trying to isolate an energy system or any system of the body may be mentally convenient and look good in theory but in practice it is like chasing a pot of gold at the end of a rainbow. All systems of the body work together all the time and they work together synergistically to maintain a state of homeostasis. When you do a heavy lifting session it is certainly of high nervous system demand and very taxing on the muscles involved but there is also an ancillary cardiovascular effect and endocrine hormonal effect. In designing and implementing an effective long-term training program this must be taken into account. Look at how systems of the body integrate and how there is a spillover from one training method to another. Tap into the wisdom of the body, integrate to adapt to the demands of training in order to prepare for competition.