Hello. I know that the StrongFirst rule of thumb is a maximum of 10% of training should be isometrics, but can anyone explain the actual reasoning why behind this? (I am assuming specificity of training / being able to move well instead of just staying still, type thing, but just checking.)
Secretes of Soviet Sports Fitness and Training
One the source on the use of 10% in a training program with Isometrics comes from Dr Michael Yessis book, listed above.
Yessis is one of the leaders in the strength field. Yessis speaks Russian and translated the Soviet's training research into a magazine, "The Soviet Sports Review". Some universities have copies of the magazine in their archives. Those are still referenced in research.
The 10% Isometric Training Recommendation?
That is a good question. There nothing that I have seen on the reason for the 10% Isometric recommendation.
With that said, very few lifters every use Isometric and Eccentric Training in their training program or understand how to use it.
Two of the most knowledgeable Strength Coaches understand how to program Isometrics are...
Josh Bryant
Combining isometric training with CAT can help even the most stagnant lifter power through to a new PR. Bill March set several world records in weightlifting during the 1960’s. He was probably also the first American to use Dianabol. March didn’t attribute his accomplishments to steroids...
www.t-nation.com
and
Chris Thibaudeau
thibarmy.com
Interesting Aspects of Isometrics
1) Isometrics allow you to increase Maximum Strength around 15% above and below the position of the movement.
Thibaudeau goes into how this allows you to increase strength where you sticking point is in a movement is.
With that in mind, where the bar stop moving isn't your sticking point.
Car Analogy
Think of your sticking point as a car that you are diving that runs out of gas. The car will keep rolling until it stops.
That means where the car stops isn't where you ran out of gas. The same applies to your sticking point.
Thus, with Isometric Sticking Point Training in a movement, in let's say a Power Rack, the Isometric needs to be performed an inch or two below where the bar stopped moving.
2) Training Percentage
Many competitive lifter base their training percentage off their Competition Max, their personal best on that particular day.
The issue with that is that your 1 Repetition Max varies from training session to training session. Your personal competition best on that one day is not the same when you go back to training.
A great example of that is...
The Russian Training Percentage Method
The Russians based their training on their 1 Repetition Max; which was unobtainable with higher training percentages. Thus, their volume of High Training Percentage appeared to be much lower than the Bulgarians.
The Bulgarian Training Percentages
The Bulgarian Training Percentages were much more realistic.
The Bulgarian Training Percentages were based on their "Daily Training Max". As we know strength fluctuates from week to week and day to day.
Thus, the Bulgarian success was incorrectly view as a result of their greater volume of training with High 1 Repetition Max Training Percentage based on their Competition Max; not so.
With that said, I am not quite sure how they were able to determined their "Daily 1 Repetition Max" to program their training for each particular day.
My guess is that they probably used some type of early "Velocity Based Training" or "Auto-Regulation" to determine their 1 Repetition Max for each training session.
The Same Training Percentages
What the research shows is the Russians and Bulgarians Training Percentage were essentially the same.
The confusion that continues is the belief that the Bulgarian's 1 Repetition Max Percentage Training was based on their Competition Max like the Russians; it Was Not!
Unfortunately, that misinformation continue to be perpetuated.
This bring us back to...
Isometric Maximum Strength Training
One of the primary benefits of Isometric Training is that it allows you to perform the Isometric Action with your Maximum Strength in each training session; there is no guess work on what part of the Training Percentage Scale your are in.
Less Taxing
Isometric, as well as Eccentric Training, is less taxing than exercises composed of an Eccentric-Concentric Action, like a Squat.
Isometric Training allows for faster recovery from training sessions.
While Eccentric Training is less taxing that Eccentric-Concentric Movements, Eccentric Training produces greater muscle damage, which require a longer recovery period.
As per...,
"Wound Healing"
The greater the damage to the body, via training, surgery, sickness, etc, the longer the recovery time required.