There has been tons of discussion lately about the CNS.  As best I can tell, the CNS became part of the everyday lifter’s vernacular sometime in the mid-to-late 90’s.  And even now, it seems that most of us don’t have a clue what we’re talking about.
The terms “CNS activation”, “CNS fatigue”, and a host of other like terms get tossed around.  But it’s like nobody stops to ask what the CNS is to begin with.  Biology makes no issue about it.  The CNS is the brain and the spinal cord.  Period.  So if your “CNS is fried, bro” then what you’re literally saying is that your brain and spinal cord are tired.
Okay, whatever.  I don’t even care about that too much.  But if you look a little closer, you see guys switching exercises a lot to “keep the CNS fresh” or “keep from frying the CNS”.  Well, even a rudimentary understanding of how muscles work will tell you that no matter how you change the exercise, voluntary movement starts in the brain, travels down the spinal cord, and then to the peripheral nervous system. 

On the contrary, I’ve become more and more aware that CNS fatigue, though it is real, is not all that common.  And people who do experience it tend to be very emotionally driven when they train.  If you’re the kind of guy who listens to loud thrash metal during training, gets all jacked up to hit a lift, often misses, etc… then you’re a candidate for some central systemic fatigue.  If you’re not and you have more of a “workman’s attitude” while training, then chances are you won’t experience that kind of fatigue.  You see, it’s not the weight on the bar that is stressful.  It’s the psychological arousal.  I’ve seen this in my training, in the training of many of my athletes, validated it with various tests, corroborated it with other coaches and other coaches’ tests.  To me, I’ve seen enough evidence of this to accept it as fact.  Intensity by itself isn’t stressful.  Volume is stressful (less is required at high intensities, of course).  Psychological arousal is stressful. 
Anyway… this isn’t really about the CNS and how we’ve bastardized the term in strength training circles.  It’s about something I realized recently.  Momentum is important in your performance.  A lot of us have realized this, but at least for me it’s been difficult to verbalize.  But I suppose I had an epiphany or something because it’s all very clear to me now.

Momentum is critical to anything fitness-related.  If you’ve never trained before, we tell you to train consistently and put the time in to see real changes in the body.  It’s not any one training session that “makes the difference”, but rather it’s the culmination of all of the training.  This is pretty common knowledge when it comes to beginning lifters, but intermediate and advanced lifters aren’t immune to the cumulative effect of training either.

The problem is that as you become more advanced, the more fine the edge of the blade, the more profound effect a slip-up can have.

Let me give you an example of what I mean.  This past weekend, I traveled to a seminar.  I flew from my house to Ohio, hung out and talked quite a bit on Friday.  All day Saturday I was talking training or presenting.  I presented for a total of 5 hours.  Then we went to dinner and sat up talking about stuff until 10:00PM.  The next day we were in the gym all day long doing hands on stuff, presenting, etc.  Then at the end, we went to dinner again and talked training until late.  Maybe that just sounds like a lot of talking, but I’m here to tell you that when I got up on Monday morning to train, I was exhausted.  And my training went pretty poorly.  I flew back home, slept, etc.  The next day I felt better, but was still tired.  Training still went poorly.  The next day I just did some GPP work.  The next day I tested my lifts.  It went pretty badly.  The momentum of the previous week was ongoing.  I had missed lifts, etc.

Contrast that with another example where you consistently do the training, things are going right in and out of the gym… as long as you keep making smart decisions, you keep riding the wave, building your strength, etc.  This even seems to be true in a more micro-environment.  If you go to a Powerlifting meet, the opening squat is most important because it sets the tone for the meet.  If you miss your opener, it’s an uphill battle for a victory in the squat.  And show me a guy who is 1 for 3 after squats and I’ll show you a guy who, more often than not, will miss at least one, probably two benches.  And if he is 2 for 6 at the end of the bench, how do you think deadlift is going to go?  Can you pull out of ruts like that?  Of course.  But it’s an uphill battle.  You’re fighting momentum.  On the other hand, if you are 3 for 3 on squats, you’re 3 for 3 on benches, then you’re probably in a good place mentally and feeling “on” for the deadlift.

The point of all this is much bigger than just an anecdote on attempt selection at the meet.  It has to do with the way you train everyday.  And not just the way you train in the gym, but everything you do that "prepares" you.  And by contrast everything that un-prepares you.  You have to build momentum.  Get momentum on your side so good training – and good training results – are easier to come by.  If you’ve been on a downward swing, voluntarily take a step back.  That could be lowering the weights, taking a day off, etc.  It really depends on you and what’s going on in your training.  But when you come back, start conservatively.  Put in a good, conservative workout.  Then the next workout, build on it.  Then build on it again.  Take what’s there – take what your body gives you on a given day (autoregulation).  But build on each session.  Don’t go overboard or make dumb decisions because that takes momentum out of your side. 

The thing is there is so much that is like this.  Skip a session?  Lost some momentum.  Went too crazy and missed some reps that you shouldn’t have?  Lost some momentum.  Trained when you should have taken a nap?  Lost some momentum.  Didn’t eat how you were supposed to?  Lost some momentum.

What’s the matter?  Is that too restrictive for you?  Tough.  We say the same thing to noobs all the time.  “Gotta put in the time and effort.”  We are no different.  It’s just that after we get to a certain level, we think we can slack off once a week or something and it won’t catch up with us.  If anything, all this stuff gets more critical as you get advanced.

If you’re looking for the take-away, here it is.  It’s not all that sexy or glamorous.  Do something every day to get you closer to your goals.  Already do something every day?  Then you probably need to do something every hour to get you closer to your goals.  What is that “something”?  I don’t know.  I don’t know you.  Maybe training.  Maybe stretching.  Maybe nutrition or visualization or something else.  Maybe read something educational.  But you have to build momentum.  Build a track record of good decisions and success in your pursuits, then your goals will come a lot easier.