Grey book question

[Griffin727]

So on page 128, it states that doing DE helps increase motor units. So can the PNS be improved, but not the CNS? If that's the case then why do verticals not improve with DE on squats. Or is this statement stating it teaches you to use all of your genetic motor units the most productive way, pretty much practice. I figured the DE day just only useful for a light day for lower body lifts, because I would just press hard on a light upper day.

[Mark Rippetoe]

I have a hard time with acronyms, even though they are fashionable. What is the "PNS"?

[Griffin727]

Peripheral Nervous System, pretty much every nerve but the spinal cord. I didn't think nerves had much of an adaptive ablity like muscle belly's. I guess I'm confused on what you mean by increases motor nerves. I thought motor nerves were a 100 precent genetic. DE is dymanic effort day. I feel like this would be useless for most people expect for maybe as a light day on lower body lifts. As for the upper body if focusing on bench, the press is the most superior light day one can do.

[Mark Rippetoe]

Nerves have a very limited capacity to adapt. DE is best thought of as Practice.