I was doing some research on CNS fatigue and came across this awesome thread. I feel the same way as you as far as wanting to be in the gym 7 days a week, lol.
Anyways, here is an interesting article about CNS fatigue that may be worth reading and was surprising and wanted some input, especially the end that stated how fast our CNS recovers.
https://bayesianbodybuilding.com/cns-fatigue/
I've been into bodybuilding (never got on stage tho) since I was 16y/o and I'm in my late 40's now. Based on my nutrition, ergogenics, rest, economics, and occupational stress, I have tried anywhere from EOD, to 3 on/1 off and at the most I went 5 on/ 2 off.
My training routine for the past ten years have been pretty much EOD with some fluctuations in-between based on social obligations. I make it a point to train each bodypart once per cycle
Back
Chest
Quads/calves
Shoulders
Arms
Hamstrings
I am lucky to say that my mind-muscle connection as well as my exercise choice has allowed me to primarily stimulate the intended muscle group such that "peripheral fatigue" is not a factor. Also, I only spend about 45 minutes in the gym, which includes the warm-ups but not the cool down (due to time-constraints) so with that little time my workouts are pretty high-intensity.
Sorry for the long post but here's my question...My occupational stress and limited access to nutrition pretty much forced me to train EOD. However, for the past couple of years I transferred to a Monday-Friday "desk" job that is about 95% stress-free and allows me to eat pretty much every 2-3 hours. I also get 7-8 hours of sleep nightly and coupled with being on prescribed TRT (also take the usual supps that most people use like a multi, creatine, fish oil,etc),
I was thinking about increasing my training to 4-5 days on/ 1 off with everything else status quo. Based on the opinion that CNS recovery occurs quicker than previously thought and that my bodypart split allows for specific muscle recovery, I'm hoping it could work?