The CNS controls everything; if it's fried your performance is going to suck. So you have to be careful about CNS intensive methods and allowing for proper recovery of the CNS. CNS intensive training methods are the max effort method in which you are lifting extremely heavy weights for a max or near max attempt and the dynamic effort method in which you are lifting light weights very fast. Sprinting and all types of plyos are also CNS intensive activities.
Ideally, you never want to perform two CNS intensive workouts on back to back days. The nervous system needs adequate recovery and although you may not be sore the next day after a CNS intensive workout, that doesn't mean that you are ready to train.
So if you do a 1 rep max squat on Monday you need to do something like repetition upper body work and/or some light running drills or cardio or whatever on Tuesday. What you don't want to do is sprint, jump or lift heavy again. You should ideally separate CNS intensive days by 48 hours. Therefore if you have to incorporate sprints into the weekly schedule it is usually best to do them as a double session on your max effort days. So on Monday morning you would run your sprints and then on Monday night you would do your max effort squats. If you are really pressed for time you could do a short sprint workout outside and then walk into the gym for your max squats.
If you are simply training for bodybuilding this is not as important but if you are training for strength/performance this rule needs to be taken under strict consideration.
While CNS recovery is important to consider I should also point out that it has gotten to be a very hot topic recently and I think some people may be taking it too far. Actually, I know they are taking it too far. It's good to constantly make advances and stay up to date on the latest scientific discoveries and apply them to our training but we never want to get too caught up in this either. If your schedule doesn't work out perfectly with the structure of CNS intensive days and non CNS intensive days, don't freak out about it. When we were growing up we didn't know anything about this and we were all ok. I used to jump, trying to touch the rim at least fifty times per day in high school. And when I finally got there, I continued to jump fifty times per day trying to dunk for the next few years. That was high intensity plyos being done 365 days per year and you know what happened? My vertical went up.
Walter Payton was probably the greatest running back of all time and he famously did hill sprints every single day of every off season. Would he have been better if he skipped a day between? Who knows? But the point I am trying to make is that you have to always be aware of and take into consideration the science, but never be afraid of hard work and breaking the rules when you have to; we don't live in a perfect world. The guy who works harder than anyone else will always have an advantage over the science geek who worries about and plans his training to the T. It's like Rocky versus Ivan Drago…
Years ago nobody ever discussed or heard of CNS fatigue or adrenal fatigue and now everybody and their mother is worried about it and is p*ssy footing around like a bunch of school girls. Get over it. If you drink too much coffee and don't always get ten hours of sleep and get stressed out on occasion and train harder than everyone you know, it aint gonna kill ya. You'll be fine. I don't know who is writing this stuff but I keep getting questions about it and now I feel bad that I ever mentioned it in the first place. It just gives the weak another excuse to remain weak.
Yes, CNS and adrenal fatigue are real issues and you should be concerned about avoiding both of them by trying to adhere to the rules I listed above. But the reality is most people just need to learn how to train harder and smarter and stop making excuses.
Besides, rules are made to be broken. Right?
Source 4 Foods Never To Eat