Friday, April 30, 2010

CNS "burnout"?

I found this piece from Justin Harris and I wanted to put it up because I found it interesting. While I often have to use terms with "CNS" in it because so many believe in this theory (created and perpetuated by bro-science) in relation to training, I have never really believed in the whole "CNS burnout" theory in relation to lifting weights. As Justin notes here, you'll hear this term thrown all over the place on message boards but there isn't any peer reviewed material backing up this bro-science. If anyone can post any up feel free to do so. I personally think it was started by the LSCN master himself. Now you have all of these minions running around spouting it off like it's a scientifically proven theory. I think a lot of it started after Mike Mentzer and his HIT theories resurfaced about a decade and a half ago. People started chanting about how training to failure all the time would result in adrenal burn out, with literally no evidence behind this.

Since then DoggCrapp has had people training to failure over and over again on multiple exercises in a session, 20 rep squats, and high rep deadlifts. All in a week, and what happened? People ate a lot and grew like crazy. Even from a bro-science standpoint, if CNS burnout and adrenal fatigue were true, that's the one program that would have proven it. Yet people just got big and strong on it.

From Harris -

"I won't get too involved with the CNS training and strength sports, but I don't get too excited about that concept either.

Adrenal fatigue is thrown around quite frequently these days and I don't really know why. There is no medically recognized disease of adrenal fatigue. If you look into the term adrenal fatigue you'll find many articles posted on bodybuilding and powerlifting forums, but you'll find no scientific or peer reviewed articles on the subject.
If you search for peer reviewed journals on adrenal insufficiency, you'll find addison's disease, a disease which is caused when the adrenal glands do not produce enough of the hormone "cortisol."
This is the exact opposite of what people write about when mentioning adrenal fatigue. They talk about excessive cortisol production from various forms of stress. Adrenal insufficiency is exactly the opposite of this.

The central nervous system and the peripheral nervous system are quite different systems. The system that is most readily affected by training and forms of physical stress is the somatic branch of the peripheral nervous system.

The PNS connects the "body" to the CNS and is exposed to injury and toxins in ways the CNS isn't. The CNS is hidden away in the brain and spine and protected by the blood-brain barrier.

Specialized strength training is important and has come a long way, but I believe there can be too much specialization. Specialization to the point of limiting progress and variance in physical stimulus isn't progress.

I've always trained to get bigger muscles by using heavier and heavier weights. I don't know whether that is bodybuilding training or powerlifting training.
I know that my training didn't really change a whole lot between training for football, training for bodybuilding, and training for powerlifting and I did well in each of them. Perhaps I could have done better with more specialized training, but I have too much fun at the gym to stress about those things.

I'm not here to get in a debate about the CNS. There are people who've had success with all forms of training. I am never one to discourage anyone from doing something that has brought themselves and their clients success. My feelings on the subject stem from what I understand about psychopharmacology and how it is affected from physical stimulus."



  1. Paul-

    The only thing I can comment on is experience when doing the circa-max cycle. We were using heavy band tensions (sometimes 2 strong and 1 average band a side) looped around the bad pegs and up over the bar. We kept the set/reps low, usually 5 sets of 2, and then would work up to a single at the end with the bands still on.

    The first few cycles of this, after every single band squat workout, all of us felt like we had the flu about 10 minutes after the work sets. You felt sick, fuzzy, and your legs felt like walking around on noodles. This lasted for hours. Something I had never experienced before or since (even when doing 20s, etc.)

    All we could ever figure is it had something to do with the CNS in some way. No proof, but it was weird as hell and always on the circa-max with crazy bnd tensions.


  2. I think since it was a new movement could have played a big part. When new guys comes in to bench or squat the path of the bar is all over the place, much in the same way.

    I have always likened it to writing. When you are first learning to write you are all sloppy and it's very slow to spell even short words. After muscle memory is developed you can write at a much faster pace. This is layman terms of course.

    Obviously this is connected to brain function as well, like anything you do. But I have pushed through weeks of bad workouts before staying heavy, then hit weeks of awesome ones. From an anecdotal standpoint (yeah I'm gonna whup out some bro-science myself LOL), if adrenal burnout were the reason for my grinding workouts, you would see a continued downward spiral. However I have worked through these many times before and hit PR's out the other side. I would often run my doggcrap cycles for months without a break because I kept gaining.

    I think this side of training is largely unexplored from a scientific standpoint, and will be a while before we really have a better idea of these things.

    Of course some people don't even believe EMG studies when it comes to showing what muscle actually do the work on certain movement patterns.

  3. ****But I have pushed through weeks of bad workouts before staying heavy

    I meant "while staying heavy" i.e. training as heavy as I could still.

  4. So it seems like PNS burnout is a more accurate phrase? Like you said, you can't train in the red all the time. Something will eventually put the brakes on.

  5. Or a branch of the PNS. But that opens a whole new can of worms doesn't it?

  6. Hey Paul:

    New to your blog...just wanted to say its very informative and will be a regular visitor...cheers