Sunday, March 31, 2013

Does Speed Work work? My response to Mike Tuchscherer’s article. Part 2


Does Speed Work work? My response to Mike Tuchscherer’s article
Part 2


Click here for the part 1 of this article.




INTENSITY, LOAD, EFFORT, EXERTION…

One thing I forgot to emphasize and explain in Load-Velocity profile (from now on L-V profile or L-V trade-off) was that all reps are done at MAXIMUM INTENT to lift as fast as possible (within technical limit). In another words EFFORT of each rep, at each LOAD was MAXIMAL.  In some strength circuits this is called C.A.T (Compensatory Acceleration Training).

I have created a graph to explain that submax weights could be done with less than maximum effort.

Load-Velocity profile done with different effort levels

Using the above example I could lift 120kg at 0.55 m/s with maximal effort. With submax effort I will lift it slower (I have used percentage of the maximal velocity for a given load as percent of maximal effort, although this relationship might not be linear like this). Also, it might not be possible to slow down certain loads too much (especially not 1RM) due sticking points and TUT (endurance).

We use the word intensity to refer to a given percentage of 1RM. Recent paper by James Steele (thanks to Bret Contreras for pointing it out) argues against it and you can quickly see why in the above graph. I can lift submax load with maximal or submaximal effort. Steele recommends using intensity of load, intensity of effort to make things clearer:

In RT, we could talk of the intensity OF load as being the percentage of 1 RM or maximum voluntary contraction that is being used. Or we might talk of the intensity OF effort involved during an exercise with the caveat that we can only gain subjective measurement of the sense of effort through RPE, and measurement of motor unit (MU) recruitment in RT provides a physiological variable correlating with effort, with max MU recruitment representing max effort independent of load --- Steele J. Br J Sports Med Published Online First

Up to this point we have talked about only single rep velocity at certain load. Using less than maximal load one could perform couple of reps until exhaustion (technical or complete failure). On the following picture is the table by Dan Baker for experienced trainers.


Repetition maximum continuum
 This is another fundamental concept in strength training and it is called repetition maximum continuum or Load-Reps trade-off. 

Please note that there is no special reference to the effort of those reps (or speed) so they are usually done at self-selected pace. Also, there is an important difference in L-R relationship between exercises, level of lifters, etc. One could use Reps-till-fatigue to estimate 1RMs, although as said there is a big difference between exercises, lifters, etc thus most coaches use different tables.

In R-L continuum we are again talking about MAXIMUM reps done at certain load (%1RM). Using submax effort one could perform lower number of reps.  If we say that lifting for maximum reps athlete reaches maximum exertion (or exhaustion), then lifting for submax number of reps one reaches submax exertion.

This is one of the main principles of Mike Tuchscherer’s Reactive Training System. Mike uses RPE scale (Rate of perceived exertion) to quantify exertion for number of reps performed. You can read more about it HERE.

Another table is relative intensity which I’ve picked up from Donnell Boucher (click HERE). I am presenting here one example of such a table:

Relative intensity table

What is common to both of these tables is the concept of quantifying how hard a given set was (in terms of exertion at the end of it). This is useful for programming since all-out-sets demands a lot from the body and demands more time for recovery.

I will visualize it by using Dan Baker table

Performing submax number of reps at certain %1RM




 Please note that this is not universal percent table – it is only an example that you can use. For more info please refer to work by Mike Tuchscherer. I have provided outline of his system HERE and HERE.

As you can see there are two inter-related fundamental concepts L-V and L-R. It is crucial to understand them, but it is also crucial to understand the terminology issues. Thus we have

Intensity of load (%1RM)

Intensity of effort (lifting speed, intent to lift fast – concentric only or concentric-eccentric; tempo)

Intensity of exertion (expressed sometimes as 5[10] which means 5 reps of possible 10 reps; one could use RPE system as well or relative intensity table)

As you can see this is all related to one set. Then we have more programing variables relating to volume aspects, like number of sets, total number of reps, tonnage, rest between sets, etc.

The authors and coaches often confuse effort and exhaustion (I have wrote about it HERE). The example that James Steel gave depict the situation perfectly:

Along this vein of thought, however, we might also consider the differentiation between sense of effort and the physical sensations associated with exercise, which, considering the above definition of intensity, would also be inappropriately labelled as such. Indeed, these phenomena have also been recently called upon to be differentiated appropriately within the articles published in BJSM.16 17 Smirmaul16 offers a practical example appropriate to RT in this regard suggesting, “A short maximal voluntary contraction for leg extension, for example, will induce a maximal sense of effort while, initially, other unpleasant sensations will probably be modest. Repeating this maximal contraction several times, however, will increase these unpleasant sensations continuously, whereas sense of effort will always be the same (ie, maximal).” Indeed, I and my colleagues have questioned the use of RPE in RT to determine relative effort.6 Shimano et al9 showed that, when repetitions were continued to MMF, RPE was similar at 60%, 80% and 90% of 1 RM for most exercises;
* MMFMomentary Muscular Failure

Why is all of this important? It is important to differentiate between different methods and understand that a lot of authors forget to describe all related parameters, so we end up not knowing what the exact training was.  


MOTOR UNIT RECRUITMENT AND SIZE PRINCIPLE

One analogy I like to make is the example of DC motor with attached battery.  

Battery = Nervous System, motor = Musculo-skeletal system; Both = motor system


In this simple example motor is the muscle and battery in nervous system. For a same level of voltage motor will behave differently (in terms of angle velocity, torque, power) based on the load at his axis (inertial, friction, air, etc).

This is pretty much along the lines with Load-Velocity profile – velocity of the motor will depend on the external load, but also on the voltage (and in this case voltage is effort).

Effort = voltage

  
Thus lifting with maximal effort is like lifting with maximal voltage not matter what load is on the bar.

Another example might be lifting submax weights to exhaustion/failure (RE method). Suppose that the motor can fatigue and decrease his force/velocity output for the same voltage over time.  You attach certain load to the motor which is 50% of his maximal torque and use 50% of voltage. He is going to rotate slowly but as the motor get “tired” one needs to increase voltage to maintain rotation at certain velocity. After you eventually reach the highest voltage and are unable to increase more, the motor will stop.

This is along the lines of lifting submax weight until failure. At the end it will result with you recruiting you maximal voltage.

To make things more confusing sometimes the battery might get tired or reduce its voltage based on some feedback from the motor (e.g. temperature) to avoid complete motor breakdown (for this one needs more complex circuitry). Now we are talking about central fatigue as opposed to peripheral fatigue (at the level of the motor). Usually they are both involved in larger or smaller degree depending on what time frame we are talking about (single set, workout, week, etc), exercise, intensity, etc. You can read more about it in Cesey Butt article HERE.

Why am I saying all of this? Because according to Ralph Carpinelli it is not only the intensity of the load (%1RM) that determines motor recruitment (i.e. battery voltage):

…That is, the size principle does not support the popular resistance training recommendation to use a maximal or near maximal resistance. The size principle and interpolated twitch studies support the contention that if maximal
motor unit activation is desired, a maximal or near maximal effort at the end of a set of repetitions— regardless of the amount of external resistance—will elicit maximal motor unit activity. Effective resistance training does not require the use of a maximal or near maximal force to stimulate the available motor units and produce significant increases in muscular strength.

… Despite the plethora of opinions in the resistance training literature, the specific mechanisms of fatigue and exactly what constitutes an optimal stimulus for strength gains are unknown. If a maximal— or near maximal—effort is applied at the end of a set of repetitions, the evidence strongly suggests that the different external forces produced with different amounts of resistance elicit similar outcomes

…Despite the plethora of opinions in the resistance training literature, the specific mechanisms of fatigue and exactly what constitutes an optimal stimulus for strength gains are unknown. If a maximal— or near maximal—effort is applied at the end of a set of repetitions, the evidence strongly suggests that the different external forces produced with different amounts of resistance elicit similar outcomes


So the things are not so simple. I am not sure I completely agree with Ralph Carpinelli regarding the training recommendations (read the whole article), but at least this shed up some light on the issue that it is not only intensity of load (%1RM) that is important in increasing strength and maximizing muscle recruitment. Lifting submax weights to exhaustion will result in maximal recruitment as well.

I tend to believe that this is dynamic animal – there is certainly a dynamic threshold in intensity of load (%1RM) that a given trainee have to use and this might change over time. Also, there might be fatigue limit to performing submaximal weights to exhaustion and this might limit total work overall and thus limit strength gains.

I don’t want to turn this into discussion on lifting to failure or not or single set vs. multiple set, since I believe both are tools in your toolbox and needs to be done at certain periods for maximum results. What is important to get from this is that for maximal motor unit recruitment (according to Carpinelli) it might not be necessary to use maximal loads or near maximal loads.

And in the end this is the static picture I alluded to in the first part. We know that the goal is to increase 1RM, to increase battery voltage, to increase velocity around circa maximal weights, to improve technique (efficiency). But we don’t know what is the best method to come there. We know the destination, but we are not sure what the best journey is.

Will maximum recruitment yield most improvements in 1RM over time or is it something else? Force output? Number of grinding reps? Volume of lifts over 80%, over 90%? Total number of reps? At the end of the day we still don’t know.  That’s why we have programs that yield same or very similar outcomes by using totally different approaches – one might use low frequency of grinding reps (maximal recruitment, maximal exertion) usually known as HIT; one might use high volume and frequency of lower intensity of load (%1RM) like Sheiko. One  might combine different methods like Westside guys do to reach maximum recruitment in most things they do (ME for maximum recruitment with highest intensity of load; DE for maximum effort with lower intensity of loads for maybe maximum recruitment but with lower load; RE for maximum recruitment as the fibers get tired). Key message is that even if we know the static picture we still don’t know what change that static picture over time. And there are a lot of ways to skin a cat.



TALKING ABOUT THE JOURNEY

What Mike Tuchscherer believes [as far as I can tell from his writings] that will bring these improvements is the following – (1) force output during an exercises is very important stimulus and since force output changes with increasing loads [I will cover this soon] then higher loads are more important than lower, and (2) higher volume of work with this higher force output and (3) technique similarity. This is his rationale behind ditching lower intensity (50-70%) Dynamic Effort methods and putting more focus into higher intensity of load (sets @8RPE).

Basically, even if there is maximal muscle recruitment during Dynamic Effort method or Repetition Effort the force output is lower than with higher loads (%1RM) and hence will bring less improvements over time.  

I am not sure how correct this is, but  I wanted to explore my Force output during different loads. I am going to use my bench press (with pause) as an example. Here is my force output during set with 60kg:

Gym Aware output with 60kg bench press

Please note that the force is estimated using reverse dynamics using position change of the barbell. Refer to this paper for more info. 

To understand the forces involved I will create a simple mechanical model. 

Simple mechanical model...
What you can see on the above graph is estimated Muscular Force. When the muscular force is over gravity force (in this case 60kg x 9,81 = 588N) then barbell will start accelerating. If the muscular force is below gravity force the barbell will start decelerating, as you can see happening during the last 1/3 of the concentric phase. If the muscular force is below zero, that means I am actually pulling the barbell down (rowing) and as you can see that happens during the last period of the lift. This happens during the lighter weights (in terms of %1RM) and I believe in greater amount during the bench press than squat (your feet are not bolted to the ground so you can pull down actually).

Here is the table from Sanchez-Medina et al. Importance of the Propulsive Phase in Strength Assessment. Int J Sports Med 2010; 31: 123 – 129 where they showed relative contribution of the breaking phase in the bench press.
Breaking phase over  20-100 %1RM



According to this table - only loads over 80% 1RM produce no breaking phase. This is one of the reasons for using chains and bands when doing Dynamic Effort method – to extend the propulsive phase and create more force.

Here is my force output with 100kg.  







Gym Aware output with 100kg bench press

This time I need to overcome 100kg x 9,81 = 981N to get the bar moving. And there is not below zero force (no pulling the bar).


On the next table I have compared Peak Force output during concentric phase against different loads when reps are done with maximum effort (C.A.T.).

Peak force output over %1RM continuum in bench press


Peak force is the highest force achieved during the concentric phase. Using mean force output will yield weight of the barbell – so I have used peak force.

As you can see there is a curvilinear relationship (I have used polynomial equation on the graph and linear on the table, as you can see R2 is higher on graph). Bret Contreras posted similar picture from a study by Swinton et al. that is pretty much in line with this one.


According to my bench press data, to reach over 90% of Peak Force output one needs to use loads over 82% 1RM. To reach over 80% of Peak Force output one need to use more than 68% 1RM.

To make sure that this is also the case with squat I compared my squat numbers with even jump squat. 

Gym Aware output during squat jump with 20kg 
When I put everything in table this is what I get

Peak force output over %1RM continuum in squat

According to this sample, loads needed to reach over 90% of Peak Force are over 84% 1RM and to reach over 80% of Peak Force one need to use over 73% 1RM.  Here is the table

% Peak Force
Bench
Squat
>90%
>82% 1RM
>84% 1RM
>80%
>68% 1RM
>73% 1RM


It seems that Mike Tuchscherer is right in this regard – One cannot reach peak barbell force outputs with submaximal loads even if he utilizes compensatory acceleration.

[Disclaimer: The forces explained here are the forces acting on the barbell and not Ground Reaction Forces. To estimate those I have added 100% of my BW to the load . This is what I got:
Estimated GRF forces using 100% BW along with barbell weight

As you can see, using 100% BW into calculation I managed to produce the same peak force during the 20kg countermovement jump and 160kg squat. Does this mean I need to work more on my strength levels since I’ve utilized full its potential in the jump? I have no clue – I would need more data and need to think more about this since I just discovered it for the purpose of this article. Having a force plate might help as well.

This is also an example of result dependency on measurement method as I have alluded in this post on power measurement. Anyway, according to this study barbell kinematics should not be used to estimate barbell and body system center of mass in the back squat. So using barbell velocity as a representative overestimated barbell-body center of mass velocity and hence acceleration, power and force.

Anyway, if I stick to squat performance (without jump squat) to reach over 90% of peak GRF one need to use more than 74% 1RM and to reach over 80% of peak GRF one need to use more than 54% 1RM – a lot less than when we consider only barbell force. The question now is which one is more important – GRF or barbell force?

End of Disclaimer]

I believe that you are confused at this moment. Welcome to the club. To summarize – Mike Tuchscherer is right when he says that one can’t achieve peak forces with loads less than 80% 1RM when one take forces applied to the barbell only. In the case with peak GRF (in squat; estimated using LPT, but I would need force plate to be more certain) one needs loads higher than 70%.  Please note that Dynamic Effort uses 50-60% 1RM raw loads.

One thing to consider is that my C.A.T. with submax loads is NOT the same as Dynamic Effort. In Dynamic Effort one is performing both eccentric and concentric parts explosively for 2-3 reps, plus add chains or bands to the equation and the forces might be much higher than with my pause technique. But you also have sitting on the box that might actually decrease it. Without measuring it I can only speculate.

 So even if Mike is right when it comes to force outputs, does it means that force outputs are key stimuli for strength improvement, or something else? Only the experimental study could tell us this. And not done on college kids or weak coaches (point taken), but on real powerlifters. Changes should be estimated using smallest worthwhile changes. Anyone up for an experiment give me a call.


CONCLUSION

Conclusion is that the things are complex and there are a lot of ways to skin a cat. I cannot say with any confidence that DE works or not. Plus, one needs to take into account the whole training system and not only one method the system uses It is only tip of the iceberg. This brings me to my opinions that you should take with grain of salt.

I do think that Dynamic Effort is a little bit overrated. I am leaning more toward Mike Tuchscherer’s side, but I am maintaining my skeptical attitude. Mike is probably right when he says that force outputs are lower in DE then when working with higher loads (not necessary to exhaustion; in his system around 8RPE), along with different technique of execution which might not bring transfer. But again, are these the sole things behind strength increase stimuli? We don’t know.

One thing to consider is that DE might work for the other reasons instead of developing explosive force for blasting through the sticking point (this might be an interesting study to find out). When one works with ME twice a week and really pushing it, then he is not left with much than to do easier weights (50-60%) the next two day. This is similar to the polarization of the training for endurance runners.

This is why it is important to take a look at the big picture. Numerous champs are using this Westside, but numerous tall humans are playing basketball which doesn’t prove basketball make humans tall. One could use different methods during different phases.

This study (although sketchy) showed higher improvements in bench press in group performing it with C.A.T and before velocity drops below 80% of the  best rep, even when doing less volume compared to a group who did self-selected lifting speed to failure. I am very interested in this velocity based strength training at the moment – and I believe there is a huge potential in this approach.

One idea might be to utilize accumulation phase(s) using higher number of sets, lower number of reps with relatively higher %1RM (75-80%) with NO grinding at all and with C.A.T. (that is around 8RPE according to Mike) before switching to more Westside program for couple of weeks/months, where DE might be utilized as a complement to ME session.  

I hope you have enjoyed this article without any confident conclusion.










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