Central Nervous System Series: Part 1

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So I am dedicating myself this summer to writing some more articles, and fortunately, I think I have learned just enough in the last year to put some new fresh information out. My summer vacation is underway, and right now it is the first time in 8 years that I haven't spent the months of June, July and August slaving for the man to make some extra change. So basically, this should give me an opportunity to write just a bit more than I have been in the past year.

So right now I would like to talk a little bit about the Central Nervous System (CNS). I think that this is a buzzword and popular topic in strength training today (as it should be), so lets get into it shall we? In a nutshell, the CNS is the primary controller of strength and power gains in athletic pursuits. Most of the gains that you make early in a strength training program are not the result of your muscle-tendon unit becoming stronger, but that of your CNS working more powerfully and efficiently. A simple way of looking at this is in terms of fiber recruitment. In any movement, a certain number of muscle fibers are involved. In a state of de-training, however, there will be a lot of muscle fibers that are left out in a given movement. When you train though, your body will turn on more of these fibers. You can't turn on 100% of your fibers though, except for in life/death situations (lifting a car off a baby, etc.). I beleive the maximal number you can turn on in normal situations is around 80-90%, but you get the idea.

For speed/power type work, training emphasis is usually on "recruiting the fast twitch muscle fibers/fast twitch motor neurons", which is theoretically done by doing explosive work with all out effort (to recruit all available fibers). This is why doing 3 sets of 5 depth jumps with 5 minutes rest between sets beats doing 2 sets of 100 squat jumps with a minute rest (the sets of 5 will allow each jump to be much more explosive, and thus have higher recruitment, then the 2 sets of 100).

Now eventually, in any strength program, the gains that your CNS will pick up will max out, so to speak (can't recruit any more fibers/all available fibers are now recruited), and now the only way to keep gaining strength will be for the muscle to increase in size. This is not a completely fine line (pure neuro gains for certain time/then all muscle size), but a small muscle can only produce so much power. Also, an interesting and important fact is that performance gains that are acheived by muscle size gain will last longer than those gains which are brought about by CNS recruitment gains. Part of the reason that this is true is the "soon ripe-soon rotten" principle. An athlete who does high powered CNS training for 6 weeks prior to basketball season will probably make some great gains in that 6 weeks, but will also lose it pretty quickly once the season is underway, unless he/she is somehow able to maintain that training.

Before I get onto the next section of this article, let me quickly get into what I would consider "CNS" training. I have ranked these in order of the CNS demand of these exercises.

1. True Plyometrics: Depth Jumps, Hurdle Hops, Bounding....Basically any type of max-effort rebound style exercise. These are very high demand exercises!

2. Heavy Weightlifting: Anything 80% or greater definitely falls in this category, but explosive lifts in the 50% and above range could fall in this category as well.

3. Short Sprint Work: The shorter the sprint, the higher than CNS strain. Sometimes sprint coaches will actually steer athletes with weak nervous systems towards towards longer distances in their sprint workouts to avoid overstraining the CNS. I would say sprint work that falls into this category would be any sort of max effort sprinting that is 100m or less. Hill work also falls into this category.

3. Jump and Dunk attempts: Any sort of high jump/dunk attempts would be considered a high CNS effort, but not so much as something like a depth jump. I would put this in a similar CNS category as short and intense sprint work, so I labeled them both #3.

4. Medicine Ball and Shot Throws: Any all out full body overhead or underhanded shot or med ball throw. Not talking about chest passes or ab twists here. This is more of a track and field specific exercise.

Alright, so there are some way to train the Central Nervous system.....so whats the point? Well, the point is that too much CNS specific training, or too much sequential training with an emphasis on the CNS will lead to overtraining and greater likelihood of injury. Also, although CNS training gains come the soonest, overtraining of the CNS will also last the longest (as opposed to overtraining other systems in the body). Overtrain the CNS of an athlete and they will be functioning submaximally for weeks, or sometimes even months if you did it bad enough. This alone is a very important reason to pay attention to the amount of CNS in training. I am assuming most people reading this article have, at some point in their training reached a point where they were very worn out because of this type of burnout.

Now I am not one for babying training, and only going hard once in a great while, in fact, I think that you can train hard every single day. The catch though is, that you can't train the CNS hard every day, you have to rotate the trainable facets of the human organism. A great DVD I bought in the last couple years is on the 5 biomotor abilities in athletics. They include speed, stength, endurance, flexibility, and coordination.

You can find a link giving a greater rundown of these abilities HERE: http://www.coachr.org/fitness.htm

Now really, you can divide these qualities up into CNS and non-CNS demand abilities. The CNS demand abilities would be Speed and Strength. The non-CNS demand abilities would be endurance, flexibility and coordination. I don't really recommend training the CNS hard more than 2 days a week in most situations, so a weekly setup involving the training of the different motor abilities for a team sport such as basketball could look something like this:

Monday: CNS Speed-Strength (Plyos and Weights)

Tuesday: Specific Endurance (maybe something like 10x45 second sprints)
Wednesday: Coordination and Flexibility (this could be as simple as game drills and stretching)

Thursday: Upper Body Submaximal Lifting (under 80% max)

Friday: CNS Speed-Strength (Speed and Weights)

Saturday: Endurance and Flexibility (2 mile jog and stretch)

Ok, so this is a weekly setup with 2 intense CNS training days a week. An average trainee will be able to make some decent gains off something like this for a month or two, but after that a plateau will occur because of the CNS stress. This will happen even with a switch of exercises and format. I will mention that some athletes have stronger nervous systems than others. There are a few things you can do to reduce the total CNS stress of the training system. Probably the best thing you can do to combat CNS overtraining is have an easy training week every 3rd or 4th week. This is one of the most important, but overlooked principles in sport training. In an easy training week, you could have one or zero CNS intensive days, but still train the other qualities throughout the week. The following is an example for a low CNS stress week.

Monday: Endurance/Flexibility

Tuesday: Coordination/General Strength Training

Wednesday: CNS-Weightlifting (the one intense day, but no plyos...the #1 stressor)

Thursday: Endurance/Flexibility

Friday: Coordination/General Strength Training

*General Strength Training would be bodyweight style circuit training and possibly low intensity repeated jumping drills.

So over the long haul, say 3 months time, a training set up designed to reduce CNS burnout could look like this:

Week 1: CNS 2 day

Week 2: CNS 2 day

Week 3: CNS 0 day

Week 4: CNS 2 day

Week 5: CNS 2 day

Week 6: CNS 1 day

Week 7: CNS 2 day

Week 8: CNS 2 day

Week 9: CNS 2 day

Week 10: CNS 0 day

Week 11: CNS 2 day

Week 12: CNS 3 day (shock week)

Week 13: active rest

Week 14: active rest

Week 15: start over again (bump up the volume 5-10% next time around)

So this concludes the first part of this series. The next article will talk about training the structure of the musculo-skeletal system in conjunction with the nervous system for optimal results!