Alex V posted this on a forum: I believe it’s a quote from Thibaudeau explaining a little bit about NeuroDynamics and inno-sport.
Food for thought
"Here’s a portion from one of the new chapters that will be added to the paperback version of my new book. I think that it might help you understand DB’s principles (I do believe that I’m a wee bit better teacher… ).
Unfortunately I wasn’t able to include the numerous charts and figures from the chapter…
The nature of the neural drive
To keep it simple, all motor actions first start by a neural action. Either a voluntary motor command or a reflexive one. This action, or command, is sent to the appropriate motor units. Upon reception of the impulse (potential of action) the motor unit is activated, producing force. This is obviously a gross oversimplification of the neuromuscular action, which would require a book on its own to fully explain. But for the scope of this book, it’s sufficient and will allow us to better understand how to manipulate the neural action/command processes.
The neural drive has three distinct characteristics which will vary in relative importance depending on the type of action needed. These three characteristics are:
A. Rate: How fast can the neural drive activate or deactivate motor units.
B. Duration: For how long the neural drive keeps the motor units activated.
C. Magnitude: The importance of the neural impulse. The larger is an impulse, the motor motor units it will activate.
Now, for any given muscle action there will be a different type of neural drive. A neural drive can be rate-dominant or duration-dominant. An important magnitude can occurs with both types of dominance as we will illustrate.
Rate-dominant drive of a high magnitude: In this first type of drive, we can see that the rate of the drive is very important. That is, it doesn’t take long for the neural drive to reach its peak. On the other hand, the duration of the drive is short. In real life we thus have a very rapid force production lasting for only a brief period of time. The relatively high magnitude indicates a high level of force production. This type of drive is characteristic of shock training methods such as plyometrics, depth landings and reactive strength exercises (catching a load and quickly reversing its motion).
Rate-dominant drive of a low magnitude: In this second example we still have an important rate and a short duration of action. But this time the magnitude is lower. Meaning that we are still seeing a rapid and brief neural drive, but the actual force production is not that high. Rapid unloaded limb movements and regular jumps and bounds are good examples.
Duration-dominant drive of a high magnitude: This type of neural drive occurs when we need to produce a high level of force for a relatively long period of time. We mean long compared to the rate-dominant drive. Generally speaking we are talking anywhere between 4 to 12 seconds when force production is concerned. This type of drive is characteristic of actions requiring a high level of force production that must be sustained. A good example is heavy lifting: lifting a near-maximal or maximal weight might take you 4-12 seconds. This requires that the nervous system sends a sustain drive for the duration of the effort.
Duration-dominant drive of a low magnitude: This type of drive is found in movements where you must produce a moderate amount of force for a longer period, when talking about strength training 20-70 seconds is a good approximation. In that case we can sustain the effort for longer than during a duration-dominant drive of a high magnitude, but the output is lower. This means that the neural drive is active for longer, but it is of lesser importance. A good example of such a drive would be found in sub-maximal lifting at a controlled tempo (sets of 8-20 reps).
Importance of the type of neural drive
Knowing the type of neural drive present in a given muscle action is crucial for several reasons. Among the most important we can name:
a. Reducing the risk of CNS overtraining
b. Higher rate of progress by avoiding opposite types of drive within a single session
c. Selecting training methods and means adapted to the needs of the individual
d. Selection training methods and means adapted to the needs of the sport
Reducing the risk of CNS overtraining
Neural drive magnitude, rate and duration all have an impact on CNS stress. A high magnitude is extremely demanding on the CNS by itself. In fact, the more important the magnitude of the neural drive is, the greater is the ensuing CNS fatigue. The duration of the drive can also have an impact in that cumulative CNS output can place a significant burden on the neuromuscular apparatus. A long duration by itself is not really stressful: if you maintain an extremely low magnitude for a long duration the actual CNS stress is virtually nil. However when a high magnitude occurs at the same time, the cumulative CNS fatigue effect is very important. A high rate of neural drive is also demanding on the CNS, especially when of a high magnitude. However since it’s almost impossible to have both a long duration and a high rate, the cumulative CNS fatigue effect from rate work is harder to accomplish. It’s still possible to do so, by using too many total repetitions.
The most CNS-demanding neural drive is thus duration-dominant and high magnitude. The second most demanding being a rate-dominant high magnitude drive. The third most demanding is a rate-dominant low magnitude drive while duration-dominant low magnitude work is the least demanding on the CNS, which is why it’s often used as a restorative method following a period of CNS demanding work.
Higher rate of progress by avoiding opposite types of drive within a single session
For maximum results you should not mix rate-dominant and duration-dominant exercises within the same training session. This would lead to sub-optimal neural adaptations, which would impair both short and long-term progress. I have myself been guilty of using a mixed approach; the Canadian Ascending-Descending program is such an example. It did produce good results, better than traditional strength training, so at first I did not question the validity of the approach. However as I improved my understanding of the neural processes involved in training I came to the conclusion that separating rate and duration work would bring the fastest results. And it did. It takes a big man to recognize his mistakes, and I fancy myself of being relatively big! So although a mixed approach will produce good results, separating rate and duration work into different sessions will lead to an even faster rate of improvement.
I find the following combination to work very well:
Two methods in one session
- maximum effort concentric – repetitive effort concentric
- maximum effort eccentric – maximum intensity isometric
- submaximal eccentric – maximum duration isometric
- high intensity absorption – dynamic effort concentric
Three methods in one session
- maximum effort concentric – repetitive effort concentric – maximum duration isometric
- maximum effort eccentric – maximum intensity isometric – submaximal eccentric
- high intensity absorption – ballistic isometric – dynamic effort concentric
Four methods in one session
- max effort concentric – repetitive effort concentric – max duration isometric – max intensity isometric
- max effort eccentric – submaximal eccentric – max duration isometric – max intensity isometric
- overspeed eccentric – high intensity absorption – ballistic isometric – dynamic effort concentric
Selecting training methods and means adapted to the needs of the individual
Each individual will have motor unit activation properties in which he’s more efficient. For example, you might be very efficient at producing a duration-dominant neural drive. This means that you can keep on producing the required level of force for a relatively long period. This is what I call “grinders”: when lifting a maximal load the speed will be extremely slow, almost static really, but it continues to move. Grinders can produce and sustain maximum force in 5-10 seconds, however they often have problems with explosive or reactive exercises requiring a rate-dominant neural drive.
On the opposite side of the coin you have rate-dominant individuals. I call them “hit or miss” because with them they either complete a lift with seemingly room to spare, or miss it at the first sign of slowing down. For example such an individual could bench press 315lbs in 2 seconds (rather easily), but miss 320lbs! These peoples can produce a very large amount of force in a brief period of time, but they cannot sustain it for long, hence the hit or miss phenomenon.
Then you have mixed individuals who are neither rate nor duration dominant. They are pretty much equal in both types of actions.
You can get a good idea of the dominance of an individual by timing the concentric portion of a maximum strength lift (bench press or squat for example). A duration-dominant individual will complete his maximal lift in 5-10 seconds; a rate-dominant individual will complete it in 1-3 seconds and a mixed individual in 4-5 seconds.
When you know somebody’s strength (dominance) you also know his weakness: if someone is obviously duration-dominant, more rate work should be included in the program and vice versa. Sometimes an individual might participate in a sport where one type of action is not needed. Still, you should work on individual needs (individual-specificity) first and sports related needs (sport-specificity) second.
Selection training methods and means adapted to the needs of the sport
Certain sports are rate-dominant (jumps, football, sprints, throws, etc.) others are duration-dominant (powerlifting, strongmen events, etc.) and many are mixed demands. Once that individual needs are filled out, you can start to maximize those capacities involved in the sport of choice of your athlete.
But remember, individual-specificity first, sport-specificity second!
Elastic versus Contractile force production
During any given movement/muscle action force is being produced via a combination of muscle contraction and elastic action. The muscle contraction aspect is also called voluntary muscle activation while the elastic action can be called reflexive action.
Generally speaking, the importance of the reflexive action increases when there is a rapid switch from stretching to contraction (or from eccentric to concentric). The faster the transition is, the more important will be the reflexive component. On the opposite, during single regimen actions (concentric-only, eccentric-only, isometric only) and during slow transition movements, it’s the voluntary muscle activation that plays the biggest role.
Some individuals have very good reflexive properties while have weak voluntary properties or vice versa. For maximum performance it is important to establish if an athlete is less efficient in one of these types of actions. In most cases, rate-dominant athletes have better reflexive properties than duration-dominant athletes while the later have stronger contractile properties" (Christian Thibaudeau)